WEBVTT 00:01.266 --> 00:03.866 align:left position:45% line:89% size:45% ♪ ♪ 00:05.800 --> 00:08.233 align:left position:37.5% line:83% size:52.5% NARRATOR: Are rising temperatures driving 00:08.233 --> 00:11.900 align:left position:10% line:83% size:80% Earth's ecosystems past a point of no return? 00:11.900 --> 00:13.433 align:left position:37.5% line:83% size:52.5% JANE LONG: We can't go back. 00:13.433 --> 00:14.866 align:left position:15% line:89% size:75% There is no path backwards. 00:14.866 --> 00:18.200 align:left position:32.5% line:5% size:57.5% STEVE PACALA: Every year, the damages are worse. 00:18.200 --> 00:21.366 align:left position:37.5% line:83% size:52.5% NARRATOR: We have promising technologies 00:21.366 --> 00:23.966 align:left position:27.5% line:83% size:62.5% that put solutions within our grasp, 00:23.966 --> 00:27.100 align:left position:10% line:89% size:80% but are we reaching far enough? 00:27.100 --> 00:28.833 align:left position:32.5% line:83% size:57.5% FRANK KEUTSCH: We have to have emissions 00:28.833 --> 00:30.000 align:left position:35% line:89% size:55% cut to zero. 00:30.000 --> 00:32.366 align:left position:12.5% line:89% size:77.5% Even if we stop emitting CO2, 00:32.366 --> 00:36.200 align:left position:22.5% line:83% size:67.5% we still have the CO2 we've already emitted. 00:36.200 --> 00:38.800 align:left position:37.5% line:77% size:52.5% NARRATOR: So scientists are building a new toolkit... 00:38.800 --> 00:40.233 align:left position:30% line:83% size:60% ATTICUS STOVALL: It has power. 00:40.233 --> 00:42.566 align:left position:37.5% line:77% size:52.5% NARRATOR: ...to ensure a prosperous future. 00:42.566 --> 00:44.000 align:left position:15% line:89% size:75% Our society has to survive. 00:44.000 --> 00:47.466 align:left position:30% line:77% size:60% SHEILA JASANOFF: We need to reduce the heating effect. 00:47.466 --> 00:49.700 align:left position:37.5% line:83% size:52.5% NARRATOR: Cutting-edge solutions... 00:49.700 --> 00:51.800 align:left position:30% line:83% size:60% ALDO STEINFELD: It's going to be revolutionary. 00:51.800 --> 00:54.766 align:left position:22.5% line:83% size:67.5% LOLA FATOYINBO AGUEH: It's like science fiction. 00:54.766 --> 00:55.933 align:left position:35% line:77% size:55% DAVID KEITH: And there's the balloon up there. 00:55.933 --> 00:58.600 align:left position:37.5% line:83% size:52.5% NARRATOR: ...and high-risk measures... 00:58.600 --> 01:01.833 align:left position:17.5% line:83% size:72.5% I really hope we'll never have to do this. 01:01.833 --> 01:04.500 align:left position:17.5% line:83% size:72.5% It's really important that humanity has a backstop. 01:04.500 --> 01:07.033 align:left position:37.5% line:83% size:52.5% NARRATOR: ...in a race to discover: 01:07.033 --> 01:09.366 align:left position:20% line:89% size:70% can we cool the planet? 01:09.366 --> 01:11.300 align:left position:22.5% line:89% size:67.5% Right now, on "NOVA." 01:11.300 --> 01:12.466 align:left position:45% line:89% size:45% ♪ ♪ 01:33.066 --> 01:36.266 align:left position:37.5% line:77% size:52.5% JASANOFF: It's a new time in the Earth's history 01:36.266 --> 01:40.533 align:left position:20% line:83% size:70% in which we are not just inhabiting our planet, 01:40.533 --> 01:43.966 align:left position:15% line:83% size:75% we're operating as stewards of the very thing 01:43.966 --> 01:47.100 align:left position:22.5% line:89% size:67.5% that we're living on. 01:47.100 --> 01:51.466 align:left position:37.5% line:77% size:52.5% NARRATOR: Since the Industrial Revolution, humanity has been running 01:51.466 --> 01:53.766 align:left position:15% line:89% size:75% an unintentional experiment 01:53.766 --> 01:55.666 align:left position:22.5% line:89% size:67.5% in Earth's atmosphere, 01:55.666 --> 01:58.566 align:left position:25% line:83% size:65% pushing the climate to new extremes. 01:58.566 --> 02:00.500 align:left position:42.5% line:83% size:47.5% LONG: Things are going to get hot. 02:00.500 --> 02:02.733 align:left position:45% line:83% size:45% MAN: Boy, you can feel the heat. 02:02.733 --> 02:03.700 align:left position:30% line:89% size:60% This is insane! 02:03.700 --> 02:06.166 align:left position:35% line:89% size:55% Oh, my God. 02:06.166 --> 02:08.566 align:left position:40% line:83% size:50% PACALA: Attitudes have changed rapidly 02:08.566 --> 02:11.400 align:left position:20% line:83% size:70% because everyone can see for themselves 02:11.400 --> 02:14.933 align:left position:27.5% line:83% size:62.5% the climate change that is occurring. 02:14.933 --> 02:18.200 align:left position:37.5% line:77% size:52.5% NARRATOR: A child born today will witness, across her lifetime, 02:18.200 --> 02:22.000 align:left position:25% line:83% size:65% a planet transformed by rising temperature. 02:22.000 --> 02:24.533 align:left position:45% line:83% size:45% MAN: I got you, I got you. 02:25.966 --> 02:28.533 align:left position:37.5% line:83% size:52.5% NARRATOR: How did we get here? 02:28.533 --> 02:30.933 align:left position:45% line:89% size:45% ♪ ♪ 02:30.933 --> 02:32.633 align:left position:42.5% line:83% size:47.5% LONG: Every time you get in your car, 02:32.633 --> 02:34.033 align:left position:15% line:89% size:75% every time you fly a plane, 02:34.033 --> 02:35.900 align:left position:10% line:89% size:80% every time you turn the heat on, 02:35.900 --> 02:37.900 align:left position:25% line:83% size:65% all of those things are putting carbon dioxide 02:37.900 --> 02:39.333 align:left position:25% line:89% size:65% into the atmosphere, 02:39.333 --> 02:41.600 align:left position:17.5% line:5% size:72.5% and if there's more carbon dioxide in the atmosphere, 02:41.600 --> 02:45.233 align:left position:12.5% line:5% size:77.5% there's a higher temperature. 02:45.233 --> 02:48.900 align:left position:37.5% line:5% size:52.5% NARRATOR: And now temperatures have started to spike. 02:48.900 --> 02:51.666 align:left position:42.5% line:77% size:47.5% KEITH: If we keep pumping billions of tons of CO2 02:51.666 --> 02:53.166 align:left position:12.5% line:89% size:77.5% into the atmosphere each year, 02:53.166 --> 02:55.833 align:left position:12.5% line:83% size:77.5% we really will cook ourselves, literally, in the end. 02:55.833 --> 02:58.166 align:left position:27.5% line:89% size:62.5% (birds squawking) 02:58.166 --> 02:59.766 align:left position:37.5% line:83% size:52.5% NARRATOR: To stop the worst impacts 02:59.766 --> 03:03.533 align:left position:22.5% line:83% size:67.5% of planetary heating, we need rapid emissions cuts, 03:03.533 --> 03:06.466 align:left position:32.5% line:89% size:57.5% starting now. 03:06.466 --> 03:08.333 align:left position:40% line:77% size:50% PACALA: The developed nations of the world 03:08.333 --> 03:10.966 align:left position:30% line:83% size:60% need to go from the energy system they have now 03:10.966 --> 03:16.066 align:left position:10% line:83% size:80% to one that emits nothing, zero, in 30 years' time. 03:18.666 --> 03:20.333 align:left position:45% line:89% size:45% ♪ ♪ 03:20.333 --> 03:23.066 align:left position:17.5% line:83% size:72.5% The good news is, we know how to do that. 03:23.066 --> 03:26.866 align:left position:10% line:83% size:80% Renewables now are the cheapest form of electricity 03:26.866 --> 03:28.300 align:left position:32.5% line:83% size:57.5% on two-thirds of the Earth's surface, 03:28.300 --> 03:29.600 align:left position:10% line:89% size:80% and it's going to be everywhere. 03:29.600 --> 03:34.733 align:left position:37.5% line:5% size:52.5% NARRATOR: A world of carbon-free energy is coming. 03:34.733 --> 03:36.200 align:left position:25% line:5% size:65% (thunder crackling) 03:36.200 --> 03:38.600 align:left position:25% line:5% size:65% But climate impacts are coming faster. 03:38.600 --> 03:41.100 align:left position:35% line:5% size:55% KATE MURPHY: Lasers are at power. 03:41.100 --> 03:42.700 align:left position:35% line:5% size:55% There it is. 03:42.700 --> 03:46.366 align:left position:37.5% line:5% size:52.5% NARRATOR: So scientists are opening a second front in the battle... 03:46.366 --> 03:47.833 align:left position:40% line:5% size:50% STOVALL: Sweet. It has power. 03:47.833 --> 03:49.666 align:left position:37.5% line:5% size:52.5% NARRATOR: Bringing new technologies 03:49.666 --> 03:52.100 align:left position:15% line:5% size:75% to bear on the way we fight climate change... 03:52.100 --> 03:53.966 align:left position:30% line:5% size:60% FATOYINBO AGUEH: We now have so much data. 03:53.966 --> 03:56.200 align:left position:42.5% line:5% size:47.5% This is going to be a game-changer. 03:56.200 --> 03:59.900 align:left position:40% line:5% size:50% PACALA: There are a whole class of solutions 03:59.900 --> 04:02.833 align:left position:20% line:83% size:70% to actually get this job all the way done. 04:04.533 --> 04:06.900 align:left position:37.5% line:83% size:52.5% NARRATOR: By removing CO2 from the air... 04:06.900 --> 04:07.933 align:left position:20% line:83% size:70% SANDRA SNAEBJORNSDOTTIR: This little guy, 04:07.933 --> 04:10.600 align:left position:15% line:89% size:75% this is just the beginning. 04:10.600 --> 04:13.200 align:left position:37.5% line:83% size:52.5% NARRATOR: Converting CO2 from a waste 04:13.200 --> 04:14.700 align:left position:30% line:89% size:60% to a resource... 04:14.700 --> 04:19.066 align:left position:32.5% line:77% size:57.5% APOORV SINHA: We see this kind of as a testing ground. 04:19.066 --> 04:21.900 align:left position:37.5% line:83% size:52.5% NARRATOR: Even extreme measures, 04:21.900 --> 04:25.733 align:left position:10% line:89% size:80% like shielding us from the sun. 04:25.733 --> 04:26.900 align:left position:25% line:89% size:65% (machinery whirring) 04:26.900 --> 04:28.333 align:left position:40% line:77% size:50% PACALA: There's been a technical revolution 04:28.333 --> 04:30.100 align:left position:22.5% line:89% size:67.5% in the last few years 04:30.100 --> 04:32.533 align:left position:22.5% line:83% size:67.5% that's unlike anything we've seen 04:32.533 --> 04:36.066 align:left position:20% line:89% size:70% in the previous hundred. 04:36.066 --> 04:39.100 align:left position:27.5% line:83% size:62.5% This is a problem with a solution. 04:39.100 --> 04:44.033 align:left position:37.5% line:77% size:52.5% NARRATOR: Can a new wave of climate tech take us the rest of the way 04:44.033 --> 04:47.200 align:left position:35% line:83% size:55% to turn down the global thermostat? 04:47.200 --> 04:50.000 align:left position:40% line:77% size:50% KEUTSCH: We need to look at everything that's out there-- 04:50.000 --> 04:51.833 align:left position:27.5% line:89% size:62.5% natural solutions, 04:51.833 --> 04:53.766 align:left position:27.5% line:89% size:62.5% CO2 sequestration, 04:53.766 --> 04:57.166 align:left position:22.5% line:89% size:67.5% solar geoengineering. 04:57.166 --> 04:59.433 align:left position:10% line:83% size:80% There may be this idea out there that nobody has come up with yet 04:59.433 --> 05:01.366 align:left position:25% line:83% size:65% that could be really transformative. 05:01.366 --> 05:06.500 align:left position:45% line:89% size:45% ♪ ♪ 05:13.400 --> 05:17.133 align:left position:37.5% line:5% size:52.5% NARRATOR: Cooling the planet means, first, stopping more CO2 05:17.133 --> 05:19.166 align:left position:15% line:5% size:75% from entering the atmosphere 05:19.166 --> 05:22.900 align:left position:22.5% line:5% size:67.5% and then finding ways to remove it. 05:22.900 --> 05:28.133 align:left position:22.5% line:5% size:67.5% But just how much CO2 are we talking about? 05:28.133 --> 05:31.733 align:left position:27.5% line:5% size:62.5% Imagine you filled the National Mall all the way 05:31.733 --> 05:36.033 align:left position:10% line:5% size:80% from the Lincoln Memorial to the Capitol steps with coal... 05:36.033 --> 05:40.933 align:left position:45% line:89% size:45% ♪ ♪ 05:40.933 --> 05:42.800 align:left position:22.5% line:83% size:67.5% ...and you piled it up all the way 05:42.800 --> 05:48.533 align:left position:27.5% line:83% size:62.5% to the top of the Washington Monument ten times. 05:48.533 --> 05:52.700 align:left position:10% line:5% size:80% That would be a gigaton of coal. 05:52.700 --> 05:58.600 align:left position:22.5% line:5% size:67.5% "Giga" means billion, so that's a billion tons. 05:58.600 --> 06:02.733 align:left position:10% line:83% size:80% Now, we actually burn ten times that much carbon every year. 06:02.733 --> 06:05.966 align:left position:15% line:83% size:75% People actually go dig that stuff up out of the ground, 06:05.966 --> 06:07.733 align:left position:20% line:89% size:70% ten billion tons of it, 06:07.733 --> 06:11.466 align:left position:27.5% line:83% size:62.5% and set it on fire in power plants, in engines, 06:11.466 --> 06:13.266 align:left position:10% line:89% size:80% in factories all over the world. 06:13.266 --> 06:14.700 align:left position:22.5% line:89% size:67.5% (imitating combustion) 06:14.700 --> 06:17.600 align:left position:45% line:89% size:45% ♪ ♪ 06:17.600 --> 06:20.533 align:left position:10% line:83% size:80% And then because that carbon has reacted with oxygen, 06:20.533 --> 06:22.566 align:left position:22.5% line:83% size:67.5% ten gigatons of carbon is burned, 06:22.566 --> 06:28.133 align:left position:17.5% line:83% size:72.5% but it creates 37 gigatons of CO2. 06:28.133 --> 06:33.333 align:left position:37.5% line:77% size:52.5% NARRATOR: At our current rate, that's just one year of CO2 emissions. 06:33.333 --> 06:35.500 align:left position:45% line:89% size:45% ♪ ♪ 06:35.500 --> 06:38.633 align:left position:25% line:83% size:65% To blunt the impacts of heating the planet, 06:38.633 --> 06:41.333 align:left position:12.5% line:89% size:77.5% we need to shrink that number, 06:41.333 --> 06:42.600 align:left position:40% line:89% size:50% to zero. 06:42.600 --> 06:47.500 align:left position:45% line:89% size:45% ♪ ♪ 06:47.500 --> 06:50.933 align:left position:12.5% line:89% size:77.5% But there's another problem-- 06:50.933 --> 06:53.500 align:left position:12.5% line:89% size:77.5% the gigatons that came before. 06:53.500 --> 06:55.933 align:left position:42.5% line:77% size:47.5% LONG: The single most important fact about climate change 06:55.933 --> 06:58.633 align:left position:17.5% line:5% size:72.5% is that the carbon dioxide that we emit into the atmosphere 06:58.633 --> 07:00.833 align:left position:35% line:5% size:55% stays there for thousands of years. 07:00.833 --> 07:05.566 align:left position:37.5% line:5% size:52.5% NARRATOR: Year after year, we live with the carbon dioxide 07:05.566 --> 07:10.433 align:left position:20% line:5% size:70% we've added over time-- nearly 1,000 metric gigatons 07:10.433 --> 07:14.200 align:left position:10% line:5% size:80% since the Industrial Revolution began. 07:14.200 --> 07:16.833 align:left position:42.5% line:77% size:47.5% LONG: Almost everything we emit stays there, 07:16.833 --> 07:18.400 align:left position:22.5% line:89% size:67.5% and it's staying there 07:18.400 --> 07:20.833 align:left position:15% line:83% size:75% until you do something about taking it out. 07:20.833 --> 07:22.600 align:left position:45% line:89% size:45% ♪ ♪ 07:22.600 --> 07:25.300 align:left position:37.5% line:83% size:52.5% NARRATOR: Pulling CO2 out of the air. 07:25.300 --> 07:29.100 align:left position:20% line:89% size:70% (men speaking on radios) 07:29.100 --> 07:30.633 align:left position:37.5% line:83% size:52.5% NARRATOR: It sounds futuristic, 07:30.633 --> 07:32.700 align:left position:27.5% line:83% size:62.5% but it's a problem we've encountered before. 07:32.700 --> 07:35.700 align:left position:30% line:83% size:60% JAN WURZBACHER: Remember Apollo 13? 07:35.700 --> 07:37.733 align:left position:10% line:5% size:80% It was all about CO2 filtering, right? 07:37.733 --> 07:39.666 align:left position:10% line:5% size:80% That was the big problem, how to get the CO2 out of the air. 07:39.666 --> 07:42.000 align:left position:17.5% line:89% size:72.5% (indistinct radio chatter) 07:42.000 --> 07:44.133 align:left position:37.5% line:83% size:52.5% NARRATOR: In 1970, following an accident, 07:44.133 --> 07:48.633 align:left position:10% line:83% size:80% the crew of Apollo 13 aborted a mission to land on the moon. 07:48.633 --> 07:51.366 align:left position:20% line:83% size:70% JOHN SWIGERT (archival): Houston, we've had a problem. 07:51.366 --> 07:54.200 align:left position:37.5% line:77% size:52.5% NARRATOR: Forced to return to Earth in a smaller capsule, 07:54.200 --> 07:56.933 align:left position:25% line:83% size:65% the astronauts faced a big problem. 07:56.933 --> 07:58.333 align:left position:35% line:83% size:55% WURZBACHER: You're in confined spaces. 07:58.333 --> 07:59.533 align:left position:27.5% line:89% size:62.5% People exhale CO2. 07:59.533 --> 08:00.866 align:left position:15% line:89% size:75% You need to remove that CO2. 08:00.866 --> 08:03.466 align:left position:30% line:89% size:60% (person exhales) 08:03.466 --> 08:07.533 align:left position:37.5% line:77% size:52.5% NARRATOR: Every exhale caused carbon dioxide to build up, 08:07.533 --> 08:11.166 align:left position:32.5% line:83% size:57.5% making the air increasingly toxic. 08:11.166 --> 08:12.966 align:left position:30% line:77% size:60% MAN (archival): Okay, now, let's everybody keep cool. 08:12.966 --> 08:14.233 align:left position:20% line:89% size:70% Let's solve the problem 08:14.233 --> 08:17.600 align:left position:10% line:83% size:80% but let's not make it any worse by guessing. 08:17.600 --> 08:19.200 align:left position:45% line:89% size:45% ♪ ♪ 08:19.200 --> 08:22.700 align:left position:37.5% line:77% size:52.5% NARRATOR: The astronauts survived by modifying their air scrubber 08:22.700 --> 08:25.133 align:left position:12.5% line:89% size:77.5% to remove more carbon dioxide. 08:25.133 --> 08:29.833 align:left position:32.5% line:89% size:57.5% (air flowing) 08:29.833 --> 08:33.533 align:left position:25% line:83% size:65% Inside the scrubber, negatively charged sites 08:33.533 --> 08:37.533 align:left position:10% line:83% size:80% on the filter polarize and bond with the CO2, 08:37.533 --> 08:41.800 align:left position:17.5% line:89% size:72.5% removing it from the air. 08:41.800 --> 08:47.166 align:left position:12.5% line:83% size:77.5% Could something like this work in Earth's atmosphere? 08:47.166 --> 08:48.933 align:left position:40% line:77% size:50% DENNING: There's not a lot of CO2 in the air compared to 08:48.933 --> 08:50.933 align:left position:25% line:89% size:65% nitrogen and oxygen. 08:50.933 --> 08:54.500 align:left position:17.5% line:83% size:72.5% Imagine a box with 10,000 ping pong balls in it 08:54.500 --> 08:56.633 align:left position:30% line:83% size:60% and four of them are painted black-- 08:56.633 --> 09:01.366 align:left position:15% line:89% size:75% those are the CO2 molecules. 09:01.366 --> 09:03.600 align:left position:10% line:83% size:80% Trying to find those four balls out of that big box 09:03.600 --> 09:05.533 align:left position:10% line:89% size:80% full of ping pong balls is hard! 09:05.533 --> 09:10.366 align:left position:45% line:5% size:45% ♪ ♪ 09:12.866 --> 09:17.233 align:left position:37.5% line:77% size:52.5% NARRATOR: Removing CO2 from a spacecraft is one thing. 09:17.233 --> 09:21.400 align:left position:10% line:83% size:80% Removing it from our atmosphere poses a much bigger challenge. 09:21.400 --> 09:23.966 align:left position:45% line:89% size:45% ♪ ♪ 09:23.966 --> 09:26.300 align:left position:30% line:89% size:60% Is it realistic? 09:26.300 --> 09:29.100 align:left position:35% line:77% size:55% WURZBACHER: Most people to whom we told we are taking CO2 09:29.100 --> 09:31.266 align:left position:17.5% line:83% size:72.5% out of the air would say, "You're crazy." 09:33.733 --> 09:37.033 align:left position:12.5% line:83% size:77.5% But here you see a full-scale direct air capture plant. 09:37.033 --> 09:40.166 align:left position:22.5% line:83% size:67.5% You see it consists of 12 individual modules 09:40.166 --> 09:41.666 align:left position:27.5% line:83% size:62.5% capturing the CO2 out of the air. 09:41.666 --> 09:44.000 align:left position:45% line:89% size:45% ♪ ♪ 09:44.000 --> 09:46.333 align:left position:37.5% line:83% size:52.5% NARRATOR: Jan Wurzbacher is a co-founder 09:46.333 --> 09:49.500 align:left position:32.5% line:83% size:57.5% of Climeworks, a Swiss start-up specializing 09:49.500 --> 09:54.166 align:left position:30% line:83% size:60% in what's called direct air capture. 09:54.166 --> 09:58.333 align:left position:12.5% line:83% size:77.5% Through this side, we suck in ambient air with 400 PPM-- 09:58.333 --> 10:00.766 align:left position:15% line:83% size:75% that's 400 parts per million CO2. 10:00.766 --> 10:04.733 align:left position:45% line:89% size:45% ♪ ♪ 10:04.733 --> 10:10.133 align:left position:10% line:83% size:80% And on the other side, we expel about 100 PPM CO2 content. 10:10.133 --> 10:13.500 align:left position:27.5% line:83% size:62.5% So three-quarters are kept inside. 10:13.500 --> 10:17.100 align:left position:37.5% line:77% size:52.5% NARRATOR: A filter with highly reactive chemicals called amines 10:17.100 --> 10:22.500 align:left position:27.5% line:83% size:62.5% catches even small concentrations of CO2. 10:22.500 --> 10:26.200 align:left position:27.5% line:83% size:62.5% Heating the filter then breaks the bond. 10:26.200 --> 10:31.066 align:left position:35% line:77% size:55% WURZBACHER: You release the CO2 and you can extract pure concentrated CO2. 10:31.066 --> 10:33.133 align:left position:27.5% line:83% size:62.5% And then you start all over again. 10:33.133 --> 10:39.133 align:left position:45% line:89% size:45% ♪ ♪ 10:39.133 --> 10:44.933 align:left position:37.5% line:77% size:52.5% NARRATOR: But generating the energy to do this can produce its own CO2. 10:44.933 --> 10:46.766 align:left position:45% line:89% size:45% ♪ ♪ 10:46.766 --> 10:48.833 align:left position:20% line:89% size:70% Their solution for that 10:48.833 --> 10:50.766 align:left position:35% line:89% size:55% is garbage. 10:50.766 --> 10:53.900 align:left position:22.5% line:83% size:67.5% Here we are on top of the waste incineration plant. 10:53.900 --> 10:56.466 align:left position:15% line:83% size:75% The reason why we're here is the main energy source 10:56.466 --> 11:00.266 align:left position:12.5% line:83% size:77.5% for our process of CO2 capture from the air, 11:00.266 --> 11:04.700 align:left position:25% line:83% size:65% waste heat from the incineration process. 11:04.700 --> 11:08.566 align:left position:37.5% line:77% size:52.5% NARRATOR: Heat that would have been wasted instead heats the filters 11:08.566 --> 11:10.600 align:left position:27.5% line:89% size:62.5% inside the array, 11:10.600 --> 11:15.033 align:left position:17.5% line:83% size:72.5% which capture nearly 1,500 metric tons of pure CO2 a year-- 11:15.033 --> 11:19.500 align:left position:22.5% line:83% size:67.5% about what's expelled from the tailpipes of 300 cars. 11:26.800 --> 11:28.300 align:left position:40% line:83% size:50% PACALA: Once you've pulled 11:28.300 --> 11:31.900 align:left position:12.5% line:5% size:77.5% CO2 out of the atmosphere with a direct air capture machine, 11:31.900 --> 11:34.900 align:left position:17.5% line:83% size:72.5% the question is what to do with it. 11:34.900 --> 11:36.233 align:left position:35% line:83% size:55% WURZBACHER: The big picture is taking 11:36.233 --> 11:38.133 align:left position:12.5% line:83% size:77.5% one percent of CO2 out of the atmosphere 11:38.133 --> 11:40.000 align:left position:30% line:83% size:60% within the next five to ten years-- 11:40.000 --> 11:45.366 align:left position:15% line:83% size:75% that is roughly 400 million tons-- and store it underground. 11:45.366 --> 11:47.400 align:left position:45% line:5% size:45% ♪ ♪ 11:47.400 --> 11:50.866 align:left position:37.5% line:77% size:52.5% NARRATOR: Could we put carbon right back where we found it-- 11:50.866 --> 11:52.833 align:left position:35% line:89% size:55% underground? 11:52.833 --> 11:55.733 align:left position:40% line:77% size:50% PACALA: There are lots of rocks near the surface of the Earth 11:55.733 --> 11:59.233 align:left position:20% line:83% size:70% that would want to bond spontaneously with CO2. 11:59.233 --> 12:01.933 align:left position:20% line:83% size:70% There's enough of these kinds of minerals that you could 12:01.933 --> 12:06.500 align:left position:12.5% line:83% size:77.5% remove all of the atmospheric CO2 many, many times over. 12:06.500 --> 12:10.766 align:left position:45% line:89% size:45% ♪ ♪ 12:10.766 --> 12:16.066 align:left position:37.5% line:5% size:52.5% NARRATOR: One of the best places to try that out is Iceland. 12:18.433 --> 12:22.400 align:left position:45% line:89% size:45% ♪ ♪ 12:26.566 --> 12:27.600 align:left position:27.5% line:83% size:62.5% SNAEBJORNSDOTTIR: Here we are-- 12:27.600 --> 12:31.666 align:left position:17.5% line:83% size:72.5% the land of ice and fire. (laughs) 12:31.666 --> 12:33.466 align:left position:27.5% line:89% size:62.5% We have eruptions. 12:33.466 --> 12:35.633 align:left position:25% line:89% size:65% We have earthquakes. 12:35.633 --> 12:41.233 align:left position:37.5% line:77% size:52.5% NARRATOR: Iceland is an island formed out of volcanic rock called basalt. 12:41.233 --> 12:44.266 align:left position:12.5% line:83% size:77.5% We see the basaltic mountains here around me 12:44.266 --> 12:49.800 align:left position:22.5% line:83% size:67.5% and actually extending several kilometers downwards. 12:51.233 --> 12:54.933 align:left position:37.5% line:77% size:52.5% NARRATOR: Basalt is porous rock that readily bonds with CO2 12:54.933 --> 12:58.600 align:left position:30% line:89% size:60% over centuries. 12:58.600 --> 13:03.433 align:left position:12.5% line:83% size:77.5% Sandra Snaebjornsdottir's team has found a way 13:03.433 --> 13:06.000 align:left position:17.5% line:89% size:72.5% to speed up that process. 13:06.000 --> 13:07.900 align:left position:27.5% line:83% size:62.5% SNAEBJORNSDOTTIR: CarbFix is the method 13:07.900 --> 13:13.866 align:left position:30% line:83% size:60% of capturing CO2 and turning it into stone. 13:13.866 --> 13:18.800 align:left position:10% line:5% size:80% It's magic, but it's magic that already occurs in nature. 13:21.500 --> 13:25.233 align:left position:37.5% line:77% size:52.5% NARRATOR: CarbFix is turning one-third of the CO2 from this power plant 13:25.233 --> 13:30.333 align:left position:30% line:83% size:60% into solid rock in less than two years. 13:30.333 --> 13:33.966 align:left position:27.5% line:89% size:62.5% The key is water. 13:33.966 --> 13:39.333 align:left position:12.5% line:83% size:77.5% Inside this scrubber, gaseous CO2 is dissolved in water 13:39.333 --> 13:41.133 align:left position:25% line:83% size:65% to react with basalt more quickly. 13:41.133 --> 13:43.200 align:left position:27.5% line:83% size:62.5% SNAEBJORNSDOTTIR: This scrubber is actually 13:43.200 --> 13:45.100 align:left position:20% line:89% size:70% just a giant SodaStream. 13:46.533 --> 13:49.366 align:left position:37.5% line:77% size:52.5% NARRATOR: The fizzy water is then pumped into injection wells. 13:49.366 --> 13:53.200 align:left position:27.5% line:77% size:62.5% SNAEBJORNSDOTTIR: This is actually my favorite part of it all. 13:53.200 --> 13:55.800 align:left position:25% line:83% size:65% From here, the magic starts to happen. 13:57.266 --> 14:01.133 align:left position:47.5% line:83% size:42.5% This pipe extends to over 2,000 feet. 14:01.133 --> 14:07.233 align:left position:12.5% line:83% size:77.5% And there, we finally release this fluid to the rock. 14:07.233 --> 14:10.533 align:left position:45% line:89% size:45% ♪ ♪ 14:10.533 --> 14:15.366 align:left position:37.5% line:77% size:52.5% NARRATOR: Once inside the basalt, the dissolved CO2 reacts with metals 14:15.366 --> 14:21.633 align:left position:12.5% line:83% size:77.5% in the rock to form new solid minerals like calcium carbonate. 14:21.633 --> 14:24.466 align:left position:12.5% line:83% size:77.5% Once we have injected the CO2 into the rock, 14:24.466 --> 14:28.333 align:left position:25% line:5% size:65% it's there forever. 14:28.333 --> 14:30.566 align:left position:37.5% line:77% size:52.5% NARRATOR: And Sandra is looking beyond Iceland. 14:30.566 --> 14:31.933 align:left position:25% line:89% size:65% She is test-driving 14:31.933 --> 14:37.133 align:left position:17.5% line:83% size:72.5% a direct air capture unit that can suck up CO2 anywhere. 14:37.133 --> 14:39.300 align:left position:27.5% line:83% size:62.5% SNAEBJORNSDOTTIR: We don't need the power plant. 14:39.300 --> 14:40.566 align:left position:30% line:89% size:60% This can be done 14:40.566 --> 14:44.200 align:left position:20% line:83% size:70% anywhere where you have a formation to store your CO2. 14:44.200 --> 14:46.466 align:left position:45% line:5% size:45% ♪ ♪ 14:46.466 --> 14:52.266 align:left position:42.5% line:5% size:47.5% LONG: What that means is, you can go backwards. 14:52.266 --> 14:57.366 align:left position:45% line:89% size:45% ♪ ♪ 14:57.366 --> 14:59.500 align:left position:15% line:5% size:75% You can reverse the process 14:59.500 --> 15:01.733 align:left position:17.5% line:5% size:72.5% of emitting carbon dioxide into the air. 15:01.733 --> 15:06.266 align:left position:37.5% line:77% size:52.5% NARRATOR: Negative emissions technologies like direct air capture 15:06.266 --> 15:09.833 align:left position:27.5% line:83% size:62.5% could play a role in reaching net zero, 15:09.833 --> 15:13.266 align:left position:12.5% line:83% size:77.5% the moment when humans remove as much CO2 from the atmosphere 15:13.266 --> 15:15.100 align:left position:30% line:89% size:60% as they put in. 15:16.400 --> 15:22.133 align:left position:12.5% line:83% size:77.5% So why isn't this the ultimate answer to our CO2 problem? 15:22.133 --> 15:23.500 align:left position:42.5% line:83% size:47.5% LONG: These technologies are 15:23.500 --> 15:26.333 align:left position:22.5% line:83% size:67.5% very hard to scale up to a meaningful amount. 15:26.333 --> 15:27.900 align:left position:45% line:89% size:45% ♪ ♪ 15:27.900 --> 15:30.466 align:left position:35% line:77% size:55% WURZBACHER: The base module of our direct air capture plant, 15:30.466 --> 15:32.600 align:left position:30% line:83% size:60% that's a 40-foot shipping container. 15:34.166 --> 15:38.033 align:left position:10% line:83% size:80% In order to take one percent of global emissions out of the air, 15:38.033 --> 15:44.733 align:left position:22.5% line:83% size:67.5% we would need 750,000 shipping containers. 15:44.733 --> 15:49.733 align:left position:37.5% line:77% size:52.5% NARRATOR: All to remove just half a gigaton of our annual emissions. 15:49.733 --> 15:51.933 align:left position:45% line:89% size:45% ♪ ♪ 15:51.933 --> 15:55.000 align:left position:40% line:77% size:50% DENNING: Direct air capture is very expensive 15:55.000 --> 15:59.800 align:left position:10% line:83% size:80% and it takes energy to suck CO2 out of the air. 15:59.800 --> 16:01.900 align:left position:12.5% line:89% size:77.5% So I hope you're not imagining 16:01.900 --> 16:05.333 align:left position:10% line:5% size:80% direct air capture vacuuming up the entire fossil fuel emissions 16:05.333 --> 16:07.466 align:left position:12.5% line:5% size:77.5% of the world, because it ain't gonna happen. 16:07.466 --> 16:13.333 align:left position:37.5% line:77% size:52.5% NARRATOR: We'll need lower-cost clean energy everywhere 16:13.333 --> 16:16.000 align:left position:27.5% line:83% size:62.5% before the promise of direct air capture can meet 16:16.000 --> 16:17.800 align:left position:17.5% line:89% size:72.5% the scale of the problem. 16:17.800 --> 16:19.733 align:left position:30% line:89% size:60% (switch clicks) 16:19.733 --> 16:21.400 align:left position:67.5% line:89% size:22.5% M7 is on. 16:21.400 --> 16:27.266 align:left position:37.5% line:77% size:52.5% NARRATOR: So some are exploring another idea: recycling our emissions. 16:27.266 --> 16:29.666 align:left position:80% line:83% size:10% MAN: Correction factor 0.7. 16:29.666 --> 16:34.466 align:left position:42.5% line:77% size:47.5% LONG: We need to think about this problem very pragmatically. 16:34.466 --> 16:36.266 align:left position:30% line:83% size:60% We can electrify a lot of things. 16:36.266 --> 16:38.733 align:left position:15% line:83% size:75% But there are certain parts of the energy system 16:38.733 --> 16:40.100 align:left position:20% line:83% size:70% that are extremely hard to decarbonize. 16:40.100 --> 16:42.900 align:left position:45% line:89% size:45% ♪ ♪ 16:42.900 --> 16:47.166 align:left position:40% line:83% size:50% PACALA: A good example is aviation. 16:47.166 --> 16:49.866 align:left position:35% line:77% size:55% WURZBACHER: You couldn't build today a commercial airplane 16:49.866 --> 16:53.100 align:left position:27.5% line:83% size:62.5% for long distances which could fly on batteries. 16:53.100 --> 16:54.600 align:left position:20% line:83% size:70% You would just carry way too much weight. 16:56.366 --> 16:59.066 align:left position:37.5% line:83% size:52.5% STEINFELD: This is physically impossible. 16:59.066 --> 17:02.600 align:left position:10% line:5% size:80% There is no way around jet fuel. 17:02.600 --> 17:04.566 align:left position:45% line:89% size:45% ♪ ♪ 17:04.566 --> 17:08.366 align:left position:42.5% line:77% size:47.5% LONG: We need to be producing fuel that, when you burn that fuel, 17:08.366 --> 17:10.700 align:left position:10% line:89% size:80% it doesn't emit carbon dioxide. 17:10.700 --> 17:14.066 align:left position:17.5% line:89% size:72.5% Remo, go ahead and rotate. 17:14.066 --> 17:16.666 align:left position:37.5% line:77% size:52.5% NARRATOR: Aldo Steinfeld thinks he's found a way. 17:16.666 --> 17:21.600 align:left position:45% line:89% size:45% ♪ ♪ 17:21.600 --> 17:24.066 align:left position:37.5% line:83% size:52.5% STEINFELD: Perfect. We are on target. 17:28.866 --> 17:33.266 align:left position:10% line:5% size:80% We have demonstrated that we can produce liquid hydrocarbon fuels 17:33.266 --> 17:34.900 align:left position:22.5% line:89% size:67.5% from two ingredients. 17:37.733 --> 17:40.400 align:left position:40% line:89% size:50% Sunlight 17:40.400 --> 17:43.533 align:left position:30% line:89% size:60% and ambient air. 17:43.533 --> 17:47.266 align:left position:45% line:89% size:45% ♪ ♪ 17:47.266 --> 17:50.066 align:left position:37.5% line:89% size:52.5% (whirring) 17:50.066 --> 17:54.100 align:left position:27.5% line:83% size:62.5% It may sound like science fiction or magic... 17:54.100 --> 17:56.000 align:left position:37.5% line:89% size:52.5% (whirring) 17:56.000 --> 17:57.666 align:left position:25% line:89% size:65% But it is chemistry, 17:57.666 --> 17:59.333 align:left position:25% line:89% size:65% it is heat transfer, 17:59.333 --> 18:02.400 align:left position:25% line:83% size:65% and also, it's a lot of engineering. 18:02.400 --> 18:05.233 align:left position:45% line:89% size:45% ♪ ♪ 18:05.233 --> 18:09.500 align:left position:37.5% line:77% size:52.5% NARRATOR: Aldo captures CO2 and water from the air 18:09.500 --> 18:12.600 align:left position:25% line:83% size:65% and feeds them into a solar reactor. 18:12.600 --> 18:16.000 align:left position:37.5% line:83% size:52.5% STEINFELD: Solar radiation is reflected 18:16.000 --> 18:20.566 align:left position:12.5% line:83% size:77.5% and concentrated at the focus by a factor of 5,000. 18:20.566 --> 18:23.666 align:left position:20% line:5% size:70% It is like the intensity of 5,000 suns. 18:23.666 --> 18:26.700 align:left position:37.5% line:83% size:52.5% NARRATOR: Concentrated solar energy 18:26.700 --> 18:29.733 align:left position:10% line:83% size:80% drives a reaction that generates a synthetic gas, 18:29.733 --> 18:33.500 align:left position:27.5% line:83% size:62.5% which can then be converted into fuels. 18:33.500 --> 18:36.666 align:left position:22.5% line:5% size:67.5% And here in my hands, I have an example of 18:36.666 --> 18:39.500 align:left position:30% line:89% size:60% solar methanol. 18:39.500 --> 18:42.900 align:left position:45% line:89% size:45% ♪ ♪ 18:42.900 --> 18:44.200 align:left position:37.5% line:83% size:52.5% NARRATOR: When it's burned, 18:44.200 --> 18:47.100 align:left position:20% line:83% size:70% the carbon in this fuel returns to the atmosphere. 18:47.100 --> 18:53.300 align:left position:17.5% line:83% size:72.5% But since it was harvested there, the net CO2 is zero. 18:53.300 --> 18:54.666 align:left position:12.5% line:89% size:77.5% This is called carbon-neutral, 18:54.666 --> 18:58.566 align:left position:17.5% line:83% size:72.5% and hundreds of scientists like Aldo are working to make 18:58.566 --> 19:02.333 align:left position:10% line:89% size:80% carbon-neutral fuels a reality. 19:04.666 --> 19:07.500 align:left position:30% line:83% size:60% If they succeed, annual net emissions would drop 19:07.500 --> 19:11.033 align:left position:10% line:89% size:80% by as much as one billion tons. 19:11.033 --> 19:15.333 align:left position:17.5% line:83% size:72.5% It's going to be something revolutionary. 19:16.900 --> 19:20.933 align:left position:37.5% line:77% size:52.5% NARRATOR: But with these fuels up to six times the cost of standard fuel, 19:20.933 --> 19:26.866 align:left position:27.5% line:83% size:62.5% it's a revolution that has only just begun. 19:26.866 --> 19:28.966 align:left position:15% line:89% size:75% But it raises the question: 19:28.966 --> 19:33.966 align:left position:22.5% line:83% size:67.5% what else can we make by recycling CO2? 19:33.966 --> 19:36.666 align:left position:40% line:77% size:50% DENNING: Carbon is this incredible building block. 19:36.666 --> 19:37.933 align:left position:30% line:89% size:60% Think of it like 19:37.933 --> 19:40.500 align:left position:12.5% line:83% size:77.5% those little sort of Lego toys that we used to have, 19:40.500 --> 19:42.833 align:left position:20% line:83% size:70% only there's four little plug-ins for it. 19:42.833 --> 19:46.333 align:left position:20% line:83% size:70% So you could bond carbon to carbon to carbon to carbon 19:46.333 --> 19:49.433 align:left position:15% line:89% size:75% to build all kinds of stuff. 19:49.433 --> 19:51.566 align:left position:45% line:77% size:45% MAN: Imagine a world where everything around you 19:51.566 --> 19:53.700 align:left position:12.5% line:89% size:77.5% is made from carbon emissions, 19:53.700 --> 19:55.600 align:left position:17.5% line:83% size:72.5% from the products you use everyday 19:55.600 --> 19:57.166 align:left position:20% line:89% size:70% to the clothes you wear. 19:57.166 --> 19:59.600 align:left position:37.5% line:77% size:52.5% NARRATOR: This ad from the XPrize Foundation pitches 19:59.600 --> 20:03.566 align:left position:15% line:83% size:75% a future where recycled CO2 shapes our world-- 20:03.566 --> 20:08.200 align:left position:20% line:83% size:70% and a $20 million bounty to make that a reality. 20:08.200 --> 20:10.500 align:left position:15% line:5% size:75% We announced, "Hey, there's a $20 million prize out there, 20:10.500 --> 20:12.766 align:left position:12.5% line:5% size:77.5% "we're looking for innovators around the world. 20:12.766 --> 20:15.266 align:left position:10% line:5% size:80% "If you know how to convert CO2 into a useful material, 20:15.266 --> 20:16.466 align:left position:12.5% line:5% size:77.5% consider entering this prize." 20:16.466 --> 20:20.066 align:left position:45% line:5% size:45% ♪ ♪ 20:20.066 --> 20:21.500 align:left position:12.5% line:5% size:77.5% We are trying to help catalyze the whole ecosystem 20:21.500 --> 20:23.800 align:left position:15% line:5% size:75% of companies, of investors, 20:23.800 --> 20:25.933 align:left position:10% line:5% size:80% of people that can deploy these technologies. 20:25.933 --> 20:30.566 align:left position:45% line:5% size:45% ♪ ♪ 20:30.566 --> 20:35.800 align:left position:37.5% line:5% size:52.5% NARRATOR: The Carbon XPrize has brought five of the finalists here 20:35.800 --> 20:38.400 align:left position:20% line:5% size:70% to put their innovations to the test. 20:38.400 --> 20:44.433 align:left position:10% line:83% size:80% They're setting up shop next to a plentiful supply of CO2. 20:44.433 --> 20:46.133 align:left position:37.5% line:77% size:52.5% EXTAVOUR: They've got to take the emissions 20:46.133 --> 20:47.500 align:left position:12.5% line:89% size:77.5% from a natural gas power plant 20:47.500 --> 20:50.066 align:left position:10% line:5% size:80% and convert those into whatever material they like. 20:50.066 --> 20:53.366 align:left position:37.5% line:5% size:52.5% NARRATOR: From toothpaste... 20:53.366 --> 20:55.666 align:left position:30% line:5% size:60% to yoga mats... 20:55.666 --> 20:57.533 align:left position:35% line:5% size:55% to watches. 20:57.533 --> 21:02.466 align:left position:20% line:83% size:70% Each team will be scored on its net CO2 reduction. 21:02.466 --> 21:03.833 align:left position:37.5% line:83% size:52.5% EXTAVOUR: You could have a process 21:03.833 --> 21:05.533 align:left position:10% line:83% size:80% that uses up a lot of CO2 to make its product, 21:05.533 --> 21:08.700 align:left position:12.5% line:83% size:77.5% but in the end, just produces more CO2 than it uses up. 21:08.700 --> 21:09.666 align:left position:77.5% line:89% size:12.5% Okay. 21:09.666 --> 21:11.033 align:left position:25% line:77% size:65% We don't want that. Yup. 21:11.033 --> 21:12.966 align:left position:15% line:83% size:75% We want things that actually are reducing CO2 overall. 21:12.966 --> 21:15.033 align:left position:45% line:89% size:45% ♪ ♪ 21:15.033 --> 21:18.133 align:left position:42.5% line:77% size:47.5% SINHA: We just moved to site about two weeks ago. 21:18.133 --> 21:19.966 align:left position:35% line:83% size:55% A day later, and I think we'd have 21:19.966 --> 21:22.533 align:left position:35% line:77% size:55% (chuckling): snow in here that we'd be shoveling out, so... 21:22.533 --> 21:28.166 align:left position:37.5% line:5% size:52.5% NARRATOR: Apoorv Sinha is the C.E.O. of Carbon Upcycling Technologies, 21:28.166 --> 21:30.600 align:left position:40% line:5% size:50% or CUT. 21:30.600 --> 21:33.566 align:left position:15% line:83% size:75% We're a carbon tech company which takes carbon emissions 21:33.566 --> 21:36.633 align:left position:15% line:83% size:75% and converts them into solid nanomaterial products 21:36.633 --> 21:39.266 align:left position:10% line:83% size:80% for use in anything from cutlery to car parts. 21:39.266 --> 21:41.000 align:left position:45% line:89% size:45% ♪ ♪ 21:41.000 --> 21:45.633 align:left position:37.5% line:77% size:52.5% NARRATOR: But to make the biggest impact on CO2 and win this competition, 21:45.633 --> 21:49.566 align:left position:15% line:89% size:75% Apoorv is focused on cement. 21:49.566 --> 21:53.300 align:left position:10% line:83% size:80% Cement is an essential component of concrete-- 21:53.300 --> 21:55.000 align:left position:25% line:83% size:65% the glue that binds it together. 21:57.733 --> 22:02.333 align:left position:20% line:83% size:70% But producing it creates a lot of CO2. 22:02.333 --> 22:03.866 align:left position:42.5% line:83% size:47.5% SINHA: Cement production accounts 22:03.866 --> 22:06.800 align:left position:12.5% line:83% size:77.5% for over eight percent of the world's annual emissions. 22:06.800 --> 22:10.200 align:left position:15% line:83% size:75% If all the cement-producing companies were a country, 22:10.200 --> 22:13.400 align:left position:10% line:83% size:80% they would be the third-largest emitter in the world. 22:13.400 --> 22:16.500 align:left position:45% line:89% size:45% ♪ ♪ 22:16.500 --> 22:18.166 align:left position:37.5% line:83% size:52.5% NARRATOR: Apoorv's process converts CO2 22:18.166 --> 22:20.400 align:left position:20% line:83% size:70% into a needed ingredient for concrete. 22:20.400 --> 22:23.266 align:left position:15% line:89% size:75% And he believes it will also 22:23.266 --> 22:28.333 align:left position:10% line:83% size:80% reduce the amount of cement that concrete manufacturers need. 22:28.333 --> 22:30.600 align:left position:15% line:83% size:75% He starts with an industrial waste powder 22:30.600 --> 22:32.400 align:left position:15% line:89% size:75% left over from burning coal 22:32.400 --> 22:35.066 align:left position:30% line:89% size:60% called fly ash. 22:35.066 --> 22:36.900 align:left position:30% line:83% size:60% With the reactor that we have behind us, 22:36.900 --> 22:39.100 align:left position:30% line:83% size:60% we're scaling up and commercializing 22:39.100 --> 22:41.966 align:left position:25% line:83% size:65% an enhanced fly ash, where the fly ash has been 22:41.966 --> 22:43.666 align:left position:25% line:83% size:65% chemically activated to capture CO2. 22:46.366 --> 22:50.333 align:left position:25% line:83% size:65% As the reactor spins the fly ash, we inject CO2. 22:50.333 --> 22:53.100 align:left position:25% line:83% size:65% Ball bearings coated with a catalyst 22:53.100 --> 22:55.566 align:left position:10% line:89% size:80% speed up the chemical reaction. 22:55.566 --> 22:58.733 align:left position:25% line:83% size:65% As the ball bearings rise and fall, 22:58.733 --> 23:00.833 align:left position:25% line:83% size:65% the motion breaks up the fly ash 23:00.833 --> 23:05.400 align:left position:12.5% line:83% size:77.5% and roughs up the surface, so that more CO2 can be absorbed. 23:05.400 --> 23:08.400 align:left position:37.5% line:77% size:52.5% NARRATOR: As the CO2 penetrates the fly ash surface, 23:08.400 --> 23:11.533 align:left position:10% line:89% size:80% it forges tunnels along the way. 23:11.533 --> 23:15.500 align:left position:27.5% line:83% size:62.5% In effect, carbon dioxide has bonded with fly ash 23:15.500 --> 23:20.633 align:left position:20% line:83% size:70% to create a nanoparticle with more reactive surface area, 23:20.633 --> 23:23.233 align:left position:32.5% line:83% size:57.5% which can bind concrete together 23:23.233 --> 23:25.800 align:left position:27.5% line:83% size:62.5% and strengthen it with less cement. 23:25.800 --> 23:29.333 align:left position:42.5% line:77% size:47.5% SINHA: If concrete producers are able to use less cement 23:29.333 --> 23:31.900 align:left position:10% line:83% size:80% in their production, they could considerably reduce 23:31.900 --> 23:34.566 align:left position:20% line:83% size:70% the emissions that come from their industry. 23:34.566 --> 23:36.400 align:left position:37.5% line:83% size:52.5% NARRATOR: The question remains: 23:36.400 --> 23:40.566 align:left position:25% line:83% size:65% is it strong enough for concrete makers to buy it? 23:40.566 --> 23:42.333 align:left position:27.5% line:83% size:62.5% We just want to make sure that the technology is good, 23:42.333 --> 23:43.866 align:left position:15% line:89% size:75% and that it works really well. 23:43.866 --> 23:46.966 align:left position:42.5% line:77% size:47.5% SINHA: One of our local partners is a family-owned Calgary-based 23:46.966 --> 23:49.266 align:left position:10% line:89% size:80% concrete business called Burnco. 23:51.800 --> 23:55.433 align:left position:37.5% line:5% size:52.5% NARRATOR: Burnco is testing the strength of concrete held together 23:55.433 --> 23:58.566 align:left position:15% line:89% size:75% using Apoorv's nanoparticle. 23:58.566 --> 24:01.266 align:left position:45% line:89% size:45% ♪ ♪ 24:01.266 --> 24:02.566 align:left position:10% line:83% size:80% MAN: When the cylinder breaks, 24:02.566 --> 24:04.633 align:left position:10% line:83% size:80% we will have our final pressure read up there. 24:04.633 --> 24:10.133 align:left position:45% line:89% size:45% ♪ ♪ 24:10.133 --> 24:13.333 align:left position:35% line:83% size:55% NORM KUNTZ: These are impressive results. 24:13.333 --> 24:15.266 align:left position:22.5% line:5% size:67.5% In normal production, you're looking for changes 24:15.266 --> 24:18.366 align:left position:17.5% line:5% size:72.5% of three to four percent, and these are showing 24:18.366 --> 24:20.533 align:left position:10% line:89% size:80% results in, in double digits, 24:20.533 --> 24:22.100 align:left position:17.5% line:89% size:72.5% which is very encouraging. 24:22.100 --> 24:24.033 align:left position:45% line:89% size:45% ♪ ♪ 24:24.033 --> 24:26.333 align:left position:42.5% line:77% size:47.5% SINHA: We're very confident that we can get 24:26.333 --> 24:27.333 align:left position:12.5% line:89% size:77.5% up to a ten percent reduction 24:27.333 --> 24:30.033 align:left position:20% line:83% size:70% in the amount of cement used today. 24:30.033 --> 24:33.000 align:left position:12.5% line:83% size:77.5% But our real target is to get that number up to 20% or 25%. 24:33.000 --> 24:35.300 align:left position:45% line:89% size:45% ♪ ♪ 24:35.300 --> 24:37.966 align:left position:15% line:83% size:75% Then we start talking about significantly moving the needle 24:37.966 --> 24:41.566 align:left position:10% line:89% size:80% on the 37-gigaton-a-year number. 24:42.866 --> 24:45.733 align:left position:37.5% line:77% size:52.5% NARRATOR: But even if these new technologies can scale 24:45.733 --> 24:48.033 align:left position:20% line:89% size:70% to their full potential, 24:48.033 --> 24:51.433 align:left position:17.5% line:83% size:72.5% they could only lock away a fraction of our emissions. 24:53.100 --> 24:56.133 align:left position:42.5% line:77% size:47.5% KEITH: The total volume of CO2 that we create in the atmosphere 24:56.133 --> 24:59.400 align:left position:27.5% line:83% size:62.5% is so much bigger than the volume of any product. 24:59.400 --> 25:02.166 align:left position:10% line:5% size:80% I think people are losing track of the central issue, 25:02.166 --> 25:04.866 align:left position:15% line:5% size:75% which is, we have to reduce net CO2 emissions. 25:07.833 --> 25:09.100 align:left position:40% line:5% size:50% DENNING: The easiest thing, 25:09.100 --> 25:12.300 align:left position:27.5% line:5% size:62.5% believe it or not, is to burn less carbon, right? 25:12.300 --> 25:14.933 align:left position:15% line:5% size:75% To, to not generate the CO2 in the first place. 25:14.933 --> 25:20.866 align:left position:37.5% line:77% size:52.5% NARRATOR: Carbon-free energy like wind, solar, and nuclear power 25:20.866 --> 25:24.000 align:left position:17.5% line:83% size:72.5% can drive down most of our annual emissions. 25:24.000 --> 25:25.733 align:left position:15% line:89% size:75% And the rest could be offset 25:25.733 --> 25:28.200 align:left position:20% line:83% size:70% with negative-emissions technologies 25:28.200 --> 25:31.433 align:left position:12.5% line:89% size:77.5% that remove CO2 from the air. 25:31.433 --> 25:33.266 align:left position:42.5% line:5% size:47.5% KEITH: We will do it. 25:33.266 --> 25:36.266 align:left position:20% line:5% size:70% We will get to the day-- there'll be global celebrations 25:36.266 --> 25:38.100 align:left position:15% line:5% size:75% when we get to net zero day, 25:38.100 --> 25:42.366 align:left position:17.5% line:5% size:72.5% where we brought human CO2 emissions to zero. 25:42.366 --> 25:44.033 align:left position:25% line:83% size:65% I think it'll happen in my lifetime. 25:44.033 --> 25:45.100 align:left position:32.5% line:89% size:57.5% It is doable. 25:45.100 --> 25:46.133 align:left position:30% line:89% size:60% But on that day, 25:46.133 --> 25:48.933 align:left position:27.5% line:83% size:62.5% we have not solved the climate problem. 25:48.933 --> 25:51.866 align:left position:32.5% line:83% size:57.5% All we've done is stop making it worse. 25:51.866 --> 25:53.333 align:left position:45% line:89% size:45% ♪ ♪ 25:53.333 --> 25:57.200 align:left position:37.5% line:77% size:52.5% NARRATOR: The problem that remains is heat. 25:57.200 --> 26:00.633 align:left position:45% line:89% size:45% ♪ ♪ 26:00.633 --> 26:02.533 align:left position:40% line:77% size:50% DENNING: The temperature of the Earth is determined by heat coming in 26:02.533 --> 26:03.700 align:left position:35% line:89% size:55% from the sun 26:03.700 --> 26:06.400 align:left position:27.5% line:83% size:62.5% and heat going out by radiation out to space. 26:06.400 --> 26:09.500 align:left position:45% line:89% size:45% ♪ ♪ 26:09.500 --> 26:12.866 align:left position:37.5% line:77% size:52.5% NARRATOR: Every single day, CO2 from our past emissions 26:12.866 --> 26:15.866 align:left position:35% line:83% size:55% traps energy in the Earth's system-- 26:15.866 --> 26:20.266 align:left position:17.5% line:83% size:72.5% the same amount of energy as 500,000 of the bomb 26:20.266 --> 26:24.466 align:left position:25% line:83% size:65% dropped on Hiroshima detonating at once. 26:24.466 --> 26:27.633 align:left position:22.5% line:83% size:67.5% That heat is altering our climate. 26:27.633 --> 26:29.833 align:left position:10% line:5% size:80% What's it going to be like when, you know, 26:29.833 --> 26:32.866 align:left position:20% line:5% size:70% three months of the year are 115 degrees? 26:35.433 --> 26:40.466 align:left position:17.5% line:5% size:72.5% When vast ecosystems have died out? 26:40.466 --> 26:44.700 align:left position:12.5% line:5% size:77.5% People are going to push for, for doing something about this. 26:44.700 --> 26:49.166 align:left position:37.5% line:5% size:52.5% NARRATOR: And many fear Earth is approaching a tipping point 26:49.166 --> 26:51.766 align:left position:10% line:5% size:80% that will trigger rapid change. 26:51.766 --> 26:55.833 align:left position:40% line:5% size:50% PACALA: The uncertainties that keep me up at night are, 26:55.833 --> 26:57.266 align:left position:10% line:5% size:80% what if we aren't doing enough, 26:57.266 --> 27:00.433 align:left position:10% line:83% size:80% and there's some monster lurking behind the door 27:00.433 --> 27:01.800 align:left position:17.5% line:89% size:72.5% that all of a sudden comes 27:01.800 --> 27:03.866 align:left position:27.5% line:83% size:62.5% out into the world among us? 27:03.866 --> 27:07.800 align:left position:45% line:89% size:45% ♪ ♪ 27:12.066 --> 27:14.233 align:left position:12.5% line:89% size:77.5% It's a good idea that humanity 27:14.233 --> 27:17.200 align:left position:30% line:5% size:60% has some sort of a backstop technology, 27:17.200 --> 27:21.200 align:left position:17.5% line:5% size:72.5% something to do if we get surprised in a way 27:21.200 --> 27:22.500 align:left position:12.5% line:89% size:77.5% that is very, very dangerous. 27:25.466 --> 27:30.500 align:left position:37.5% line:77% size:52.5% NARRATOR: Some think that backstop could be solar geoengineering. 27:30.500 --> 27:34.566 align:left position:40% line:77% size:50% PACALA: It's a way to intercept sunlight coming into the planet 27:34.566 --> 27:37.933 align:left position:25% line:89% size:65% to cool the planet. 27:37.933 --> 27:41.966 align:left position:42.5% line:77% size:47.5% KEITH: The core idea is that humans might deliberately alter 27:41.966 --> 27:45.100 align:left position:12.5% line:83% size:77.5% the Earth's energy balance to compensate for 27:45.100 --> 27:47.400 align:left position:20% line:83% size:70% some of the warming and climate changes 27:47.400 --> 27:49.300 align:left position:10% line:89% size:80% that come from greenhouse gases. 27:49.300 --> 27:51.533 align:left position:45% line:89% size:45% ♪ ♪ 27:51.533 --> 27:57.133 align:left position:37.5% line:77% size:52.5% NARRATOR: Geoengineering the climate is a controversial idea. 27:57.133 --> 28:01.233 align:left position:10% line:83% size:80% But nature can show us examples of where we might start-- 28:01.233 --> 28:03.066 align:left position:40% line:89% size:50% clouds. 28:03.066 --> 28:07.633 align:left position:32.5% line:77% size:57.5% SARAH DOHERTY: A cloud is just water that's condensed down onto particles 28:07.633 --> 28:09.533 align:left position:25% line:89% size:65% into small droplets. 28:09.533 --> 28:13.666 align:left position:37.5% line:77% size:52.5% NARRATOR: These collections of droplets are, in effect, 28:13.666 --> 28:16.800 align:left position:20% line:89% size:70% floating sun reflectors. 28:16.800 --> 28:20.433 align:left position:17.5% line:5% size:72.5% Clouds play a huge role in controlling the climate 28:20.433 --> 28:22.800 align:left position:20% line:5% size:70% because they control the reflectivity of the planet. 28:25.766 --> 28:27.700 align:left position:17.5% line:89% size:72.5% Especially over the ocean, 28:27.700 --> 28:30.700 align:left position:12.5% line:83% size:77.5% you go from sunlight hitting a very dark surface, 28:30.700 --> 28:32.700 align:left position:15% line:83% size:75% where a lot of the sunlight is absorbed, 28:32.700 --> 28:35.766 align:left position:22.5% line:83% size:67.5% to sunlight hitting an extremely bright surface, 28:35.766 --> 28:38.833 align:left position:20% line:83% size:70% reflecting a lot of that sunlight back to space. 28:38.833 --> 28:43.866 align:left position:37.5% line:77% size:52.5% NARRATOR: Sarah Doherty of the Marine Cloud Brightening Project 28:43.866 --> 28:46.866 align:left position:15% line:83% size:75% is working on a way to boost that effect. 28:46.866 --> 28:50.366 align:left position:40% line:77% size:50% DOHERTY: Can we add really small sea salt particles to clouds 28:50.366 --> 28:53.633 align:left position:15% line:83% size:75% in a way that significantly increases their brightness, 28:53.633 --> 28:57.366 align:left position:20% line:83% size:70% and do so over enough of the ocean that we would have 28:57.366 --> 28:59.866 align:left position:25% line:83% size:65% a significant impact on the global temperature? 29:01.700 --> 29:04.866 align:left position:37.5% line:77% size:52.5% NARRATOR: But how do you make saltwater particles 29:04.866 --> 29:07.633 align:left position:10% line:89% size:80% and launch them up into clouds? 29:09.200 --> 29:11.133 align:left position:40% line:83% size:50% DOHERTY: What we need is a nozzle 29:11.133 --> 29:13.133 align:left position:12.5% line:83% size:77.5% like you'd see in a sort of a snowblower, 29:13.133 --> 29:15.366 align:left position:12.5% line:83% size:77.5% except that the particles that we want to produce are about 29:15.366 --> 29:17.100 align:left position:17.5% line:83% size:72.5% a thousandth the width of a human hair. 29:17.100 --> 29:20.066 align:left position:37.5% line:89% size:52.5% (humming) 29:21.200 --> 29:23.866 align:left position:37.5% line:77% size:52.5% NARRATOR: So Sarah's working with an engineer 29:23.866 --> 29:25.400 align:left position:15% line:89% size:75% who knows all about machines 29:25.400 --> 29:28.433 align:left position:35% line:83% size:55% for spraying super-fine droplets-- 29:28.433 --> 29:33.133 align:left position:22.5% line:83% size:67.5% a concept developer of the earliest inkjet printers. 29:33.133 --> 29:38.566 align:left position:27.5% line:77% size:62.5% ARMAND NEUKERMANS: In a different life, I was an engineer and a physicist. 29:38.566 --> 29:42.266 align:left position:15% line:5% size:75% I couldn't enjoy retirement anymore and just sit there 29:42.266 --> 29:43.633 align:left position:17.5% line:5% size:72.5% and watch what's going on. 29:43.633 --> 29:47.033 align:left position:12.5% line:5% size:77.5% Once you know what's going to happen or might happen, 29:47.033 --> 29:48.600 align:left position:15% line:5% size:75% you can't sit down and say, 29:48.600 --> 29:50.100 align:left position:12.5% line:83% size:77.5% "Yeah, I'm just going to enjoy life." 29:51.533 --> 29:54.933 align:left position:37.5% line:77% size:52.5% NARRATOR: Armand and his team of retired scientists 29:54.933 --> 29:57.066 align:left position:22.5% line:83% size:67.5% have been developing a cloud-brightening machine 29:57.066 --> 29:59.033 align:left position:25% line:89% size:65% for over ten years. 29:59.033 --> 30:04.133 align:left position:40% line:77% size:50% MURPHY: They have been self-funding this research in borrowed lab space. 30:04.133 --> 30:07.066 align:left position:15% line:5% size:75% PARC is a really good place for them 30:07.066 --> 30:09.066 align:left position:22.5% line:5% size:67.5% because of our history with aerosols. 30:09.066 --> 30:12.966 align:left position:37.5% line:5% size:52.5% NARRATOR: PARC, or Palo Alto Research Center, 30:12.966 --> 30:15.733 align:left position:15% line:83% size:75% has infused the Marine Cloud Brightening Project 30:15.733 --> 30:18.800 align:left position:20% line:83% size:70% with fresh expertise and cutting-edge tools. 30:18.800 --> 30:22.166 align:left position:17.5% line:83% size:72.5% Here, Kate Murphy can make aerosols 30:22.166 --> 30:24.733 align:left position:17.5% line:89% size:72.5% from just about anything. 30:24.733 --> 30:27.233 align:left position:12.5% line:5% size:77.5% This is our deep conditioner. 30:27.233 --> 30:32.066 align:left position:37.5% line:77% size:52.5% NARRATOR: Aerosols are tiny particles suspended in air. 30:32.066 --> 30:33.266 align:left position:30% line:89% size:60% This is ketchup. 30:33.266 --> 30:37.500 align:left position:27.5% line:89% size:62.5% (machine whirring) 30:37.500 --> 30:40.966 align:left position:37.5% line:77% size:52.5% NARRATOR: For clouds, they're not going to spray ketchup. 30:42.033 --> 30:43.633 align:left position:17.5% line:89% size:72.5% But Kate can help the team 30:43.633 --> 30:46.700 align:left position:15% line:83% size:75% design a nozzle for spraying saltwater. 30:46.700 --> 30:48.933 align:left position:15% line:83% size:75% Let me just give it a little water, okay? 30:48.933 --> 30:50.733 align:left position:72.5% line:83% size:17.5% MURPHY: Okay. 30:50.733 --> 30:53.066 align:left position:37.5% line:77% size:52.5% NARRATOR: Kate's expertise will help optimize 30:53.066 --> 30:54.966 align:left position:22.5% line:83% size:67.5% the size and speed of the particles 30:54.966 --> 30:58.266 align:left position:25% line:83% size:65% to propel them into marine clouds. 30:58.266 --> 31:01.266 align:left position:30% line:77% size:60% SUDHANSHU JAIN: So you're going to be redesigning the nozzle 31:01.266 --> 31:03.633 align:left position:15% line:83% size:75% based on your computational fluid dynamics? 31:03.633 --> 31:05.066 align:left position:22.5% line:83% size:67.5% Well, we hope to be able to understand the effect 31:05.066 --> 31:06.266 align:left position:40% line:89% size:50% of multiple nozzles, 31:06.266 --> 31:07.366 align:left position:22.5% line:83% size:67.5% so we would want to measure things 31:07.366 --> 31:10.033 align:left position:20% line:89% size:70% like velocity and direction. 31:11.333 --> 31:14.200 align:left position:37.5% line:77% size:52.5% NARRATOR: These crisscrossed laser beams can help reveal 31:14.200 --> 31:17.933 align:left position:15% line:83% size:75% whether Armand's nozzle will hit the mark. 31:17.933 --> 31:19.666 align:left position:40% line:83% size:50% MURPHY: The lasers are at power. 31:19.666 --> 31:22.166 align:left position:15% line:83% size:75% Um, it looks like our signal's pretty good. 31:22.166 --> 31:24.800 align:left position:10% line:77% size:80% NEUKERMANS: So can you measure the vertical velocity? 31:24.800 --> 31:26.400 align:left position:10% line:71% size:80% Do you have a measurement of that? Yes. 31:26.400 --> 31:28.200 align:left position:10% line:83% size:80% That would be of great interest to us. 31:28.200 --> 31:32.266 align:left position:40% line:77% size:50% DOHERTY: PARC will be working on developing a full spray system. 31:32.266 --> 31:33.700 align:left position:22.5% line:83% size:67.5% And then we would want to move outside, 31:33.700 --> 31:36.333 align:left position:22.5% line:83% size:67.5% into real atmospheric conditions. 31:38.033 --> 31:40.333 align:left position:37.5% line:83% size:52.5% NARRATOR: On the other side of the world, 31:40.333 --> 31:43.400 align:left position:25% line:5% size:65% outdoor research has already begun. 31:43.400 --> 31:46.433 align:left position:45% line:5% size:45% ♪ ♪ 31:46.433 --> 31:47.866 align:left position:10% line:5% size:80% Armand and the team have shared 31:47.866 --> 31:50.500 align:left position:10% line:83% size:80% their insights with researchers in Australia 31:50.500 --> 31:52.766 align:left position:22.5% line:83% size:67.5% who are testing cloud brightening as a way to cool 31:52.766 --> 31:55.500 align:left position:17.5% line:83% size:72.5% the waters surrounding the threatened coral of the reef. 31:55.500 --> 31:58.033 align:left position:45% line:89% size:45% ♪ ♪ 31:58.033 --> 32:01.133 align:left position:20% line:83% size:70% That project is targeted and local, 32:01.133 --> 32:05.966 align:left position:15% line:83% size:75% but some estimate that cloud brightening on a global scale 32:05.966 --> 32:11.466 align:left position:17.5% line:5% size:72.5% could offset all the heat trapped by our CO2 emissions. 32:11.466 --> 32:13.900 align:left position:40% line:5% size:50% DOHERTY: It will probably take a good 15 to 20 years 32:13.900 --> 32:16.900 align:left position:17.5% line:83% size:72.5% to do all of the research involved with understanding 32:16.900 --> 32:19.833 align:left position:10% line:83% size:80% how big of an effect we can have by brightening clouds 32:19.833 --> 32:23.166 align:left position:25% line:83% size:65% and also what all of the side effects might be. 32:25.166 --> 32:27.733 align:left position:37.5% line:77% size:52.5% NARRATOR: Those side effects are not well understood, 32:27.733 --> 32:29.700 align:left position:12.5% line:89% size:77.5% and could include disruptions 32:29.700 --> 32:32.100 align:left position:32.5% line:83% size:57.5% to ecosystems and rainfall patterns. 32:32.100 --> 32:35.466 align:left position:15% line:89% size:75% Further research is needed. 32:35.466 --> 32:37.866 align:left position:57.5% line:83% size:32.5% We have kids, we have grandkids... 32:37.866 --> 32:39.233 align:left position:55% line:83% size:35% We're doing it for their futures. 32:39.233 --> 32:41.666 align:left position:10% line:83% size:80% NEUKERMANS: You know, and frankly, 32:41.666 --> 32:44.300 align:left position:10% line:83% size:80% we are all in this together, whether you have kids or not. 32:47.033 --> 32:48.733 align:left position:35% line:83% size:55% NEUKERMANS: We're more than individuals. 32:48.733 --> 32:52.733 align:left position:15% line:89% size:75% Our society has to survive. 32:52.733 --> 32:55.833 align:left position:45% line:89% size:45% ♪ ♪ 32:58.200 --> 33:02.000 align:left position:37.5% line:77% size:52.5% NARRATOR: We're facing a problem that's getting worse, not better. 33:03.400 --> 33:08.200 align:left position:22.5% line:83% size:67.5% Do we need to consider more extreme measures? 33:08.200 --> 33:10.666 align:left position:40% line:83% size:50% KEUTSCH: In 15 years or 20 years, 33:10.666 --> 33:13.333 align:left position:20% line:83% size:70% humanity may find itself at a point 33:13.333 --> 33:15.133 align:left position:12.5% line:5% size:77.5% where impacts are so big that 33:15.133 --> 33:17.466 align:left position:15% line:5% size:75% there's a very large demand for fast action. 33:19.066 --> 33:22.633 align:left position:37.5% line:77% size:52.5% NARRATOR: To prepare, Frank Keutsch is starting now, 33:22.633 --> 33:27.066 align:left position:32.5% line:5% size:57.5% by researching a controversial technology 33:27.066 --> 33:30.200 align:left position:27.5% line:5% size:62.5% that goes further than brightening clouds. 33:30.200 --> 33:34.166 align:left position:27.5% line:83% size:62.5% It would brighten the entire planet. 33:34.166 --> 33:36.333 align:left position:40% line:77% size:50% KEUTSCH: Putting particles in the stratosphere 33:36.333 --> 33:39.000 align:left position:27.5% line:83% size:62.5% could reflect back some sunlight to space, 33:39.000 --> 33:41.033 align:left position:10% line:83% size:80% reducing the amount of sunlight that hits the surface 33:41.033 --> 33:43.466 align:left position:15% line:89% size:75% and cooling down the planet. 33:43.466 --> 33:46.400 align:left position:37.5% line:83% size:52.5% NARRATOR: The effect would be immediate. 33:46.400 --> 33:48.866 align:left position:27.5% line:89% size:62.5% (volcano erupting) 33:48.866 --> 33:51.133 align:left position:40% line:83% size:50% PACALA: We know this works, 33:51.133 --> 33:52.800 align:left position:27.5% line:83% size:62.5% because every time a big volcano goes off 33:52.800 --> 33:55.166 align:left position:20% line:83% size:70% and it injects aerosols into the stratosphere, 33:55.166 --> 33:57.066 align:left position:22.5% line:89% size:67.5% the planet cools down. 33:58.733 --> 34:01.466 align:left position:37.5% line:77% size:52.5% JASANOFF: That's the idea behind solar geoengineering. 34:01.466 --> 34:05.333 align:left position:10% line:5% size:80% It's like drawing a curtain over the face of the Earth. 34:08.666 --> 34:10.100 align:left position:40% line:77% size:50% KEUTSCH: The first time you hear about this, 34:10.100 --> 34:12.966 align:left position:12.5% line:83% size:77.5% you think, well, "That sounds like a really bad idea. 34:12.966 --> 34:14.633 align:left position:12.5% line:89% size:77.5% How could that not go wrong?" 34:17.833 --> 34:21.533 align:left position:25% line:83% size:65% But what we're doing to climate as humans, 34:21.533 --> 34:25.966 align:left position:20% line:83% size:70% that really to me starts seeming also quite scary, 34:25.966 --> 34:29.400 align:left position:10% line:89% size:80% and crazy, and really worrying. 34:29.400 --> 34:32.466 align:left position:20% line:5% size:70% The fact is, the CO2 is in the atmosphere. 34:32.466 --> 34:35.200 align:left position:20% line:5% size:70% Without a time machine, we can't make it go away. 34:36.900 --> 34:41.300 align:left position:15% line:83% size:75% We want to, in the long run, do carbon removal. 34:41.300 --> 34:44.100 align:left position:25% line:83% size:65% But during the time that concentrations are high, 34:44.100 --> 34:46.166 align:left position:30% line:83% size:60% we might want to do solar geoengineering 34:46.166 --> 34:47.600 align:left position:15% line:89% size:75% to reduce the climate risk. 34:47.600 --> 34:51.266 align:left position:45% line:5% size:45% ♪ ♪ 34:55.066 --> 34:56.733 align:left position:42.5% line:83% size:47.5% KEITH: All that is hard-mounted to us. 34:56.733 --> 34:57.866 align:left position:10% line:89% size:80% (group agreeing) 34:57.866 --> 34:59.400 align:left position:30% line:83% size:60% That is exactly what I was... 34:59.400 --> 35:01.300 align:left position:30% line:83% size:60% And then there's the balloon up there. 35:01.300 --> 35:03.666 align:left position:37.5% line:77% size:52.5% NARRATOR: Frank and David's team is designing 35:03.666 --> 35:04.866 align:left position:10% line:89% size:80% a first-of-its-kind experiment, 35:04.866 --> 35:06.800 align:left position:32.5% line:89% size:57.5% called SCoPEx, 35:06.800 --> 35:10.366 align:left position:12.5% line:83% size:77.5% to investigate the impacts of solar geoengineering. 35:10.366 --> 35:13.100 align:left position:17.5% line:83% size:72.5% The only place I see that conversation getting sticky 35:13.100 --> 35:15.666 align:left position:55% line:83% size:35% is where we do risk assessment on it. 35:15.666 --> 35:18.866 align:left position:40% line:5% size:50% KEUTSCH: If you put these particles out, 35:18.866 --> 35:21.033 align:left position:35% line:5% size:55% what happens when these come back down? 35:21.033 --> 35:23.100 align:left position:27.5% line:5% size:62.5% What happens when it gets into the environment? 35:23.100 --> 35:24.500 align:left position:17.5% line:89% size:72.5% Are we endangering people? 35:24.500 --> 35:27.166 align:left position:42.5% line:77% size:47.5% KEITH: There are lots of things that we might need to know 35:27.166 --> 35:30.333 align:left position:27.5% line:83% size:62.5% where the existing experimental background is bad. 35:30.333 --> 35:32.666 align:left position:15% line:83% size:75% You actually have to go out and make measurements. 35:32.666 --> 35:38.700 align:left position:45% line:89% size:45% ♪ ♪ 35:38.700 --> 35:40.366 align:left position:37.5% line:83% size:52.5% NARRATOR: The plan is to launch 35:40.366 --> 35:45.433 align:left position:27.5% line:83% size:62.5% a 100-foot balloon into the stratosphere 35:45.433 --> 35:47.466 align:left position:35% line:83% size:55% and release a plume of reflective aerosols. 35:50.533 --> 35:51.866 align:left position:40% line:83% size:50% KEUTSCH: We want to put out 35:51.866 --> 35:54.633 align:left position:30% line:83% size:60% the particles of calcium carbonate, for example, 35:54.633 --> 35:56.700 align:left position:30% line:83% size:60% and then go back through this plume 35:56.700 --> 36:00.266 align:left position:30% line:5% size:60% and see whether the evolution of the air 36:00.266 --> 36:03.766 align:left position:20% line:83% size:70% is the way we predicted based on our laboratory results. 36:05.833 --> 36:08.266 align:left position:22.5% line:83% size:67.5% This is an experiment on a very small scale. 36:08.266 --> 36:09.533 align:left position:35% line:89% size:55% And in fact, 36:09.533 --> 36:10.833 align:left position:22.5% line:83% size:67.5% the amount of material we're putting out 36:10.833 --> 36:12.833 align:left position:22.5% line:83% size:67.5% is less than a normal airplane flight puts out. 36:14.733 --> 36:16.866 align:left position:37.5% line:83% size:52.5% NARRATOR: SCoPEx may be small, 36:16.866 --> 36:19.166 align:left position:32.5% line:83% size:57.5% but many fear a large-scale manipulation 36:19.166 --> 36:21.633 align:left position:22.5% line:83% size:67.5% of Earth's atmosphere could trigger 36:21.633 --> 36:23.400 align:left position:20% line:89% size:70% a cascade of dangerous, 36:23.400 --> 36:27.733 align:left position:20% line:83% size:70% unintended consequences that ripple across the planet. 36:27.733 --> 36:29.433 align:left position:37.5% line:77% size:52.5% JASANOFF: Nothing in our scientific capability 36:29.433 --> 36:32.866 align:left position:25% line:83% size:65% actually enables us to understand the complexity 36:32.866 --> 36:35.833 align:left position:25% line:83% size:65% of the interactions that would be set loose. 36:35.833 --> 36:38.466 align:left position:27.5% line:5% size:62.5% It's not just that it lowers the temperature, 36:38.466 --> 36:40.033 align:left position:25% line:5% size:65% but what are some of the other effects 36:40.033 --> 36:41.533 align:left position:20% line:5% size:70% on the hydrologic cycle, 36:41.533 --> 36:44.166 align:left position:12.5% line:5% size:77.5% or on heat waves and droughts? 36:47.233 --> 36:50.200 align:left position:37.5% line:77% size:52.5% JASANOFF: This is a manipulation of the Earth's atmosphere 36:50.200 --> 36:51.800 align:left position:30% line:89% size:60% on a huge scale. 36:51.800 --> 36:53.600 align:left position:10% line:89% size:80% What happens if things go wrong? 36:55.066 --> 36:56.866 align:left position:37.5% line:83% size:52.5% NARRATOR: SCoPEx is designed to 36:56.866 --> 37:00.666 align:left position:10% line:89% size:80% start answering those questions. 37:00.666 --> 37:03.666 align:left position:17.5% line:83% size:72.5% But there may be effects, beyond the physical, 37:03.666 --> 37:06.633 align:left position:10% line:89% size:80% that no experiment can predict. 37:06.633 --> 37:09.100 align:left position:37.5% line:77% size:52.5% JASANOFF: If we think that there's this solution out there, 37:09.100 --> 37:10.500 align:left position:22.5% line:89% size:67.5% then people may think 37:10.500 --> 37:12.800 align:left position:25% line:83% size:65% it doesn't matter if you're polluting the planet. 37:12.800 --> 37:15.400 align:left position:42.5% line:83% size:47.5% KEITH: The root of the concern 37:15.400 --> 37:16.933 align:left position:15% line:83% size:75% is that solar geoengineering research, 37:16.933 --> 37:19.466 align:left position:17.5% line:83% size:72.5% however well-intentioned, will be used as an excuse 37:19.466 --> 37:22.333 align:left position:25% line:83% size:65% for big fossil fuels to fight emissions cuts. 37:24.666 --> 37:27.766 align:left position:40% line:77% size:50% DENNING: It's just like a sci-fi dystopian novel or something, 37:27.766 --> 37:28.833 align:left position:17.5% line:5% size:72.5% where we continue to just 37:28.833 --> 37:30.366 align:left position:27.5% line:5% size:62.5% belch all this CO2 into the atmosphere, 37:30.366 --> 37:32.533 align:left position:15% line:5% size:75% but hey, it's okay, because we got these little umbrellas 37:32.533 --> 37:37.966 align:left position:25% line:83% size:65% that are, you know, hiding us from the sun. 37:37.966 --> 37:40.300 align:left position:42.5% line:77% size:47.5% KEITH: Solar geoengineering does not get us 37:40.300 --> 37:42.600 align:left position:10% line:89% size:80% out of the ethical and physical 37:42.600 --> 37:44.266 align:left position:12.5% line:89% size:77.5% requirement to cut emissions. 37:46.400 --> 37:48.333 align:left position:37.5% line:83% size:52.5% NARRATOR: But with so much uncertainty, 37:48.333 --> 37:49.633 align:left position:15% line:89% size:75% some think we're better off 37:49.633 --> 37:53.800 align:left position:35% line:83% size:55% investing in a different kind of machine: 37:53.800 --> 37:56.266 align:left position:30% line:83% size:60% one developed in nature's own laboratory 37:56.266 --> 38:00.833 align:left position:20% line:83% size:70% over millions of years, and with a proven record 38:00.833 --> 38:03.533 align:left position:22.5% line:83% size:67.5% of safely drawing down gigatons of CO2. 38:03.533 --> 38:07.066 align:left position:42.5% line:89% size:47.5% Trees. 38:07.066 --> 38:08.500 align:left position:30% line:89% size:60% (birds chirping) 38:13.066 --> 38:14.733 align:left position:30% line:5% size:60% FATOYINBO AGUEH: When I'm going on a hike through a forest, 38:14.733 --> 38:17.800 align:left position:27.5% line:83% size:62.5% I have a tendency to look up and say, 38:17.800 --> 38:20.066 align:left position:15% line:83% size:75% "Okay, oh, that tree's about 60 feet tall." 38:20.066 --> 38:22.133 align:left position:15% line:83% size:75% And then I try to calculate in my head, okay, 38:22.133 --> 38:25.233 align:left position:17.5% line:83% size:72.5% how much carbon is stored in that tree? 38:25.233 --> 38:27.166 align:left position:22.5% line:89% size:67.5% I think this is good. 38:28.233 --> 38:31.000 align:left position:37.5% line:83% size:52.5% NARRATOR: Lola Fatoyinbo Agueh 38:31.000 --> 38:32.433 align:left position:20% line:89% size:70% is a research scientist 38:32.433 --> 38:33.933 align:left position:37.5% line:83% size:52.5% at NASA's Goddard Space Flight Center. 38:33.933 --> 38:35.166 align:left position:40% line:89% size:50% Sweet. It has power. 38:35.166 --> 38:36.566 align:left position:22.5% line:89% size:67.5% I love it when things work. 38:36.566 --> 38:39.566 align:left position:37.5% line:77% size:52.5% NARRATOR: She and her team are about to see 38:39.566 --> 38:43.100 align:left position:17.5% line:83% size:72.5% these century-old trees in a new light. 38:43.100 --> 38:45.200 align:left position:40% line:77% size:50% STOVALL: Green lights all around, if you want to do the honors. 38:45.200 --> 38:47.333 align:left position:30% line:83% size:60% FATOYINBO AGUEH: There's carbon all around us. 38:47.333 --> 38:49.366 align:left position:22.5% line:5% size:67.5% If you think of trees as a machine, 38:49.366 --> 38:52.566 align:left position:25% line:5% size:65% then trees would be a carbon capture machine. 38:56.266 --> 38:58.200 align:left position:15% line:89% size:75% When we're looking at trees, 38:58.200 --> 39:01.033 align:left position:17.5% line:83% size:72.5% about half of that weight is carbon. 39:02.866 --> 39:04.900 align:left position:37.5% line:83% size:52.5% NARRATOR: Lola and her team want to know 39:04.900 --> 39:09.933 align:left position:17.5% line:83% size:72.5% how much carbon is stored in this entire forest. 39:09.933 --> 39:12.600 align:left position:10% line:89% size:80% To measure each and every tree, 39:12.600 --> 39:14.900 align:left position:30% line:83% size:60% they're using a special kind of tool... 39:16.766 --> 39:18.400 align:left position:40% line:89% size:50% Lasers. 39:18.400 --> 39:19.900 align:left position:30% line:77% size:60% FATOYINBO AGUEH: We're using a terrestrial laser scanner 39:19.900 --> 39:24.766 align:left position:15% line:83% size:75% that shoots out billions of laser pulses every second 39:24.766 --> 39:28.366 align:left position:27.5% line:83% size:62.5% and then measures the distance from the instrument 39:28.366 --> 39:30.766 align:left position:17.5% line:89% size:72.5% to whatever is around it. 39:30.766 --> 39:34.466 align:left position:17.5% line:83% size:72.5% The data that we get back generate a point cloud. 39:36.666 --> 39:38.633 align:left position:37.5% line:5% size:52.5% NARRATOR: Billions of data points 39:38.633 --> 39:40.966 align:left position:22.5% line:5% size:67.5% form a 3-D measurement of forest volume-- 39:40.966 --> 39:45.366 align:left position:12.5% line:5% size:77.5% and the carbon stored within. 39:45.366 --> 39:50.166 align:left position:30% line:5% size:60% FATOYINBO AGUEH: It's so dense that it almost looks like a photograph. 39:50.166 --> 39:53.800 align:left position:17.5% line:5% size:72.5% It's like science fiction. 39:53.800 --> 39:56.366 align:left position:37.5% line:5% size:52.5% NARRATOR: This scan may look like reality, 39:56.366 --> 40:00.633 align:left position:27.5% line:5% size:62.5% but this is data. 40:00.633 --> 40:04.766 align:left position:17.5% line:5% size:72.5% It reveals that in an area the size of a football field, 40:04.766 --> 40:07.700 align:left position:10% line:5% size:80% these trees are storing roughly 40:07.700 --> 40:09.866 align:left position:25% line:89% size:65% 150 tons of carbon, 40:09.866 --> 40:12.200 align:left position:15% line:89% size:75% all pulled out of thin air. 40:12.200 --> 40:16.400 align:left position:17.5% line:83% size:72.5% Which prompts Tom Crowther to ask: 40:16.400 --> 40:20.433 align:left position:22.5% line:83% size:67.5% could we enlist trees in the race to draw down CO2? 40:20.433 --> 40:23.433 align:left position:45% line:5% size:45% ♪ ♪ 40:23.433 --> 40:26.166 align:left position:37.5% line:5% size:52.5% CROWTHER: Our lab is urgently trying to figure out 40:26.166 --> 40:29.100 align:left position:15% line:5% size:75% how we increase the area of forest across the globe 40:29.100 --> 40:31.933 align:left position:15% line:5% size:75% to capture as much carbon as we possibly can 40:31.933 --> 40:33.600 align:left position:25% line:5% size:65% in the fight against climate change. 40:36.833 --> 40:40.766 align:left position:37.5% line:77% size:52.5% NARRATOR: Tom's findings began with a surprising discovery. 40:40.766 --> 40:43.700 align:left position:37.5% line:77% size:52.5% CROWTHER: We thought there was around 400 billion trees on the planet. 40:45.266 --> 40:47.066 align:left position:27.5% line:89% size:62.5% But we showed that 40:47.066 --> 40:50.666 align:left position:20% line:83% size:70% there is in fact around three trillion trees. 40:54.500 --> 40:57.100 align:left position:27.5% line:83% size:62.5% There's more trees on the surface of our planet 40:57.100 --> 40:59.133 align:left position:32.5% line:83% size:57.5% than there are stars in the galaxy. 41:01.233 --> 41:03.500 align:left position:37.5% line:83% size:52.5% NARRATOR: The big question is, 41:03.500 --> 41:05.400 align:left position:25% line:83% size:65% how many more trees could we add? 41:05.400 --> 41:08.433 align:left position:27.5% line:77% size:62.5% CONSTANTIN ZOHNER: In order to understand the global forest system, 41:08.433 --> 41:10.000 align:left position:10% line:5% size:80% we need to map a lot of things, 41:10.000 --> 41:11.333 align:left position:30% line:5% size:60% we need to know where forests are, 41:11.333 --> 41:12.266 align:left position:20% line:5% size:70% where forests could be. 41:12.266 --> 41:14.633 align:left position:37.5% line:83% size:52.5% CROWTHER: We collect our data from 41:14.633 --> 41:16.733 align:left position:22.5% line:83% size:67.5% millions of locations around the world, 41:16.733 --> 41:19.000 align:left position:17.5% line:83% size:72.5% where scientists have been on the ground 41:19.000 --> 41:20.966 align:left position:15% line:89% size:75% evaluating those ecosystems. 41:22.466 --> 41:27.500 align:left position:37.5% line:77% size:52.5% NARRATOR: Data like leaf fall patterns in forests around the world. 41:27.500 --> 41:29.866 align:left position:20% line:83% size:70% I'm trying to understand the seasonal rhythm of plants. 41:31.600 --> 41:33.766 align:left position:37.5% line:83% size:52.5% NARRATOR: Microscopic organisms like 41:33.766 --> 41:36.000 align:left position:20% line:83% size:70% the tiny worms that feed the soil beneath the trees. 41:36.000 --> 41:37.333 align:left position:22.5% line:83% size:67.5% JOHAN VAN DEN HOOGEN: In just this clearing, 41:37.333 --> 41:39.166 align:left position:27.5% line:5% size:62.5% there is millions and millions of nematodes 41:39.166 --> 41:40.300 align:left position:25% line:5% size:65% living in the soil. 41:42.500 --> 41:44.233 align:left position:37.5% line:5% size:52.5% NARRATOR: And decades of satellite data 41:44.233 --> 41:48.266 align:left position:30% line:5% size:60% on factors like rainfall and temperature. 41:48.266 --> 41:51.033 align:left position:17.5% line:5% size:72.5% When I look at ecosystems most of the time, 41:51.033 --> 41:52.433 align:left position:12.5% line:5% size:77.5% I'm looking from the top down. 41:54.433 --> 41:56.266 align:left position:37.5% line:5% size:52.5% CROWTHER: And with all of that data, 41:56.266 --> 42:00.600 align:left position:25% line:5% size:65% we can start to see the patterns across the globe. 42:02.066 --> 42:04.633 align:left position:10% line:83% size:80% Using remote sensing information from satellites 42:04.633 --> 42:07.800 align:left position:25% line:83% size:65% and machine learning technologies, 42:07.800 --> 42:11.100 align:left position:25% line:83% size:65% we can generate maps that can predict which regions 42:11.100 --> 42:15.533 align:left position:22.5% line:83% size:67.5% can support new trees and which ones cannot. 42:15.533 --> 42:19.066 align:left position:32.5% line:83% size:57.5% This really is a data revolution. 42:19.066 --> 42:22.900 align:left position:37.5% line:83% size:52.5% NARRATOR: The detail is astonishing. 42:22.900 --> 42:27.433 align:left position:27.5% line:83% size:62.5% And the potential for new forests is vast. 42:27.433 --> 42:29.533 align:left position:37.5% line:77% size:52.5% CROWTHER: Outside of urban and agricultural areas, 42:29.533 --> 42:31.433 align:left position:22.5% line:89% size:67.5% there's room for about 42:31.433 --> 42:34.400 align:left position:15% line:89% size:75% 2.5 billion acres of forest. 42:40.033 --> 42:41.866 align:left position:40% line:83% size:50% ZOHNER: The area we identified equals 42:41.866 --> 42:45.033 align:left position:10% line:89% size:80% the size of the United States. 42:45.033 --> 42:48.200 align:left position:20% line:83% size:70% So there is a huge area available for restoration. 42:49.166 --> 42:51.033 align:left position:37.5% line:83% size:52.5% NARRATOR: Enough space for 42:51.033 --> 42:54.233 align:left position:20% line:89% size:70% 1.2 trillion new trees, 42:54.233 --> 42:58.400 align:left position:10% line:89% size:80% all sucking CO2 out of the air. 42:58.400 --> 43:01.400 align:left position:37.5% line:77% size:52.5% CROWTHER: If we were to restore a trillion trees, 43:01.400 --> 43:04.066 align:left position:20% line:83% size:70% the right types of trees in the right kinds of soils, 43:04.066 --> 43:06.966 align:left position:27.5% line:83% size:62.5% and have them grow to full health, 43:06.966 --> 43:11.200 align:left position:12.5% line:83% size:77.5% they could store an additional 205 gigatons of carbon. 43:11.200 --> 43:14.266 align:left position:37.5% line:83% size:52.5% NARRATOR: To put that into context, 43:14.266 --> 43:15.666 align:left position:22.5% line:89% size:67.5% we've released nearly 43:15.666 --> 43:18.966 align:left position:22.5% line:83% size:67.5% 660 gigatons of carbon into Earth's systems 43:18.966 --> 43:23.533 align:left position:10% line:83% size:80% since human industrial activity began. 43:23.533 --> 43:25.866 align:left position:37.5% line:83% size:52.5% CROWTHER: Restoring global forests 43:25.866 --> 43:29.266 align:left position:10% line:83% size:80% and conserving the vital forests that we currently have 43:29.266 --> 43:33.233 align:left position:20% line:83% size:70% could take a huge chunk out of that excess carbon. 43:33.233 --> 43:38.233 align:left position:10% line:83% size:80% This is a really massive carbon drawdown solution. 43:38.233 --> 43:41.100 align:left position:10% line:83% size:80% And we knew that this was going to make an enormous splash. 43:43.533 --> 43:46.900 align:left position:37.5% line:77% size:52.5% NARRATOR: But these findings also made waves. 43:46.900 --> 43:48.766 align:left position:22.5% line:89% size:67.5% (wildlife chittering) 43:48.766 --> 43:53.333 align:left position:30% line:77% size:60% FATOYINBO AGUEH: That study is causing a lot of debate. 43:53.333 --> 43:54.633 align:left position:30% line:89% size:60% On the one hand, 43:54.633 --> 43:57.066 align:left position:30% line:83% size:60% a lot of people are talking about 43:57.066 --> 44:00.300 align:left position:30% line:83% size:60% the potential of restoration of forests. 44:00.300 --> 44:01.633 align:left position:27.5% line:89% size:62.5% On the other hand, 44:01.633 --> 44:05.500 align:left position:10% line:83% size:80% I would say, um, a lot of people are very upset about it. 44:05.500 --> 44:10.566 align:left position:32.5% line:89% size:57.5% (bird cawing) 44:10.566 --> 44:12.733 align:left position:22.5% line:83% size:67.5% The uncertainty around the amount of carbon 44:12.733 --> 44:15.233 align:left position:22.5% line:83% size:67.5% that's stored in trees is so high 44:15.233 --> 44:18.966 align:left position:17.5% line:5% size:72.5% that we can't really make any informed recommendations 44:18.966 --> 44:21.366 align:left position:27.5% line:5% size:62.5% on how many trees we need to plant. 44:21.366 --> 44:26.300 align:left position:37.5% line:77% size:52.5% NARRATOR: Lola wants to use new technology from NASA 44:26.300 --> 44:31.466 align:left position:22.5% line:83% size:67.5% to fill those areas of uncertainty with hard data. 44:31.466 --> 44:34.066 align:left position:30% line:77% size:60% FATOYINBO AGUEH: We have over 20 Earth-observing satellites 44:34.066 --> 44:37.933 align:left position:17.5% line:83% size:72.5% right now from NASA alone looking at our planet Earth. 44:37.933 --> 44:40.566 align:left position:22.5% line:83% size:67.5% But what we're seeing is all in two dimensions. 44:40.566 --> 44:43.300 align:left position:20% line:83% size:70% What we're missing here is the third dimension. 44:44.466 --> 44:49.133 align:left position:37.5% line:77% size:52.5% NARRATOR: Enter a powerful new tool called GEDI. 44:49.133 --> 44:50.866 align:left position:12.5% line:89% size:77.5% With the same laser technology 44:50.866 --> 44:53.833 align:left position:40% line:83% size:50% used in her terrestrial scanners, 44:53.833 --> 44:56.533 align:left position:10% line:83% size:80% Lola can get a three-dimensional measure of forest carbon 44:56.533 --> 45:00.533 align:left position:40% line:83% size:50% from the International Space Station. 45:00.533 --> 45:01.700 align:left position:30% line:83% size:60% FATOYINBO AGUEH: GEDI stands for 45:01.700 --> 45:04.466 align:left position:12.5% line:83% size:77.5% the Global Ecosystem Dynamics Investigation, 45:04.466 --> 45:06.266 align:left position:15% line:83% size:75% which is what you're seeing right here. 45:06.266 --> 45:08.833 align:left position:32.5% line:5% size:57.5% This is about the size of a fridge. 45:08.833 --> 45:11.966 align:left position:22.5% line:5% size:67.5% You can see the lasers shooting down 45:11.966 --> 45:13.866 align:left position:25% line:5% size:65% out of the bottom of the instrument 45:13.866 --> 45:15.600 align:left position:40% line:5% size:50% towards the surface of the planet. 45:17.666 --> 45:18.666 align:left position:25% line:89% size:65% We actually can see 45:18.666 --> 45:20.733 align:left position:32.5% line:83% size:57.5% a full profile of plant materials. 45:24.433 --> 45:26.400 align:left position:22.5% line:83% size:67.5% The game-changer here is that 45:26.400 --> 45:28.966 align:left position:25% line:83% size:65% this is going to be, for the first time, 45:28.966 --> 45:31.833 align:left position:20% line:89% size:70% a near-global data set. 45:34.066 --> 45:35.933 align:left position:37.5% line:83% size:52.5% NARRATOR: GEDI will give clearer insight 45:35.933 --> 45:40.133 align:left position:17.5% line:83% size:72.5% on the carbon new forests could store. 45:40.133 --> 45:43.033 align:left position:22.5% line:83% size:67.5% But equally important, it can pinpoint 45:43.033 --> 45:47.533 align:left position:22.5% line:83% size:67.5% the old forest carbon we must preserve. 45:47.533 --> 45:49.800 align:left position:30% line:83% size:60% FATOYINBO AGUEH: Forests are really important 45:49.800 --> 45:56.333 align:left position:22.5% line:83% size:67.5% for our water supply, forests protect us from heat, 45:56.333 --> 45:57.933 align:left position:30% line:89% size:60% forests breathe. 45:57.933 --> 46:03.900 align:left position:17.5% line:83% size:72.5% They breathe in some ways just like we do. 46:03.900 --> 46:05.066 align:left position:22.5% line:89% size:67.5% When you lose a lot of 46:05.066 --> 46:07.566 align:left position:22.5% line:83% size:67.5% the ecosystem services that forests provide, 46:07.566 --> 46:12.133 align:left position:20% line:83% size:70% that has a direct impact on the well-being of people. 46:14.500 --> 46:17.933 align:left position:37.5% line:77% size:52.5% NARRATOR: But on an increasingly populated planet, 46:17.933 --> 46:23.633 align:left position:12.5% line:83% size:77.5% trees are not the only living things competing for land. 46:23.633 --> 46:26.700 align:left position:17.5% line:5% size:72.5% We already use all of our agricultural land 46:26.700 --> 46:28.066 align:left position:10% line:5% size:80% to feed our existing population, 46:28.066 --> 46:32.800 align:left position:15% line:83% size:75% and over the next 30 years, food demand is going to double. 46:32.800 --> 46:36.366 align:left position:30% line:83% size:60% If you take land to solve the climate problem, 46:36.366 --> 46:39.600 align:left position:15% line:89% size:75% you create another problem. 46:39.600 --> 46:42.600 align:left position:37.5% line:83% size:52.5% NARRATOR: So, is there a solution 46:42.600 --> 46:45.866 align:left position:15% line:83% size:75% that can solve more than one problem at a time? 46:45.866 --> 46:48.433 align:left position:30% line:83% size:60% WHENDEE SILVER: Some people are looking at ways 46:48.433 --> 46:50.300 align:left position:30% line:83% size:60% in which forests can help slow climate change. 46:50.300 --> 46:52.466 align:left position:35% line:83% size:55% Our research is somewhat different 46:52.466 --> 46:55.166 align:left position:40% line:83% size:50% in that we're looking at grasslands. 46:55.166 --> 46:58.400 align:left position:10% line:83% size:80% I want to have enough so that we can do experiments. 46:58.400 --> 47:02.333 align:left position:37.5% line:77% size:52.5% NARRATOR: In California, Whendee Silver is looking for a way to 47:02.333 --> 47:04.866 align:left position:17.5% line:89% size:72.5% pull down CO2 right where 47:04.866 --> 47:06.933 align:left position:27.5% line:89% size:62.5% we grow our food-- 47:06.933 --> 47:09.066 align:left position:25% line:89% size:65% Earth's grasslands. 47:09.066 --> 47:13.600 align:left position:40% line:77% size:50% SILVER: This is a classic, beautiful annual grassland. 47:13.600 --> 47:14.833 align:left position:17.5% line:89% size:72.5% Grasslands grow in places 47:14.833 --> 47:16.500 align:left position:22.5% line:83% size:67.5% where there's drought for part of the year. 47:16.500 --> 47:20.433 align:left position:27.5% line:83% size:62.5% And these grasses have developed 47:20.433 --> 47:22.200 align:left position:35% line:83% size:55% great tools for getting water, 47:22.200 --> 47:26.100 align:left position:35% line:83% size:55% particularly by growing more roots. 47:26.100 --> 47:30.366 align:left position:10% line:5% size:80% And any time plants invest a lot of their energy into roots, 47:30.366 --> 47:32.200 align:left position:17.5% line:5% size:72.5% it's like injecting carbon into the soil. 47:34.900 --> 47:39.700 align:left position:37.5% line:77% size:52.5% NARRATOR: But tilling releases that carbon and degrades the soil. 47:39.700 --> 47:42.000 align:left position:22.5% line:89% size:67.5% And producing our food 47:42.000 --> 47:45.033 align:left position:15% line:89% size:75% creates even more problems. 47:45.033 --> 47:47.100 align:left position:40% line:83% size:50% SILVER: We all eat food every day. 47:47.100 --> 47:48.600 align:left position:17.5% line:89% size:72.5% We have to grow that food. 47:48.600 --> 47:50.766 align:left position:22.5% line:83% size:67.5% And we create a lot of organic waste in the process. 47:50.766 --> 47:53.300 align:left position:32.5% line:89% size:57.5% (birds cawing) 47:53.300 --> 47:56.066 align:left position:37.5% line:77% size:52.5% NARRATOR: When organic waste sits in a landfill 47:56.066 --> 47:57.233 align:left position:30% line:89% size:60% or slurry pond, 47:57.233 --> 47:59.866 align:left position:37.5% line:83% size:52.5% it creates an oxygen-deprived environment 47:59.866 --> 48:04.366 align:left position:12.5% line:83% size:77.5% favorable to certain microbes, which in turn produce methane, 48:04.366 --> 48:09.233 align:left position:30% line:83% size:60% a greenhouse gas 34 times more potent than CO2. 48:09.233 --> 48:11.000 align:left position:22.5% line:83% size:67.5% We're trying to tackle three big problems: 48:11.000 --> 48:15.700 align:left position:12.5% line:83% size:77.5% waste, degrading soil health, and climate change. 48:15.700 --> 48:20.133 align:left position:17.5% line:83% size:72.5% We came up with something relatively simple: 48:20.133 --> 48:21.833 align:left position:35% line:89% size:55% composting. 48:21.833 --> 48:22.833 align:left position:37.5% line:83% size:52.5% NARRATOR: In composting, 48:22.833 --> 48:24.933 align:left position:37.5% line:83% size:52.5% food waste is regularly turned, 48:24.933 --> 48:27.866 align:left position:20% line:83% size:70% adding oxygen to the mix and keeping the 48:27.866 --> 48:31.833 align:left position:17.5% line:83% size:72.5% methane-producing microbes at bay. 48:31.833 --> 48:35.100 align:left position:40% line:77% size:50% SILVER: It creates this organic and nutrient-rich resource, 48:35.100 --> 48:38.200 align:left position:10% line:83% size:80% like a slow-release fertilizer, that helps plants grow. 48:44.266 --> 48:47.233 align:left position:37.5% line:77% size:52.5% NARRATOR: By turning a waste into a nutrient, 48:47.233 --> 48:49.933 align:left position:27.5% line:83% size:62.5% compost can boost plant growth 48:49.933 --> 48:54.333 align:left position:17.5% line:83% size:72.5% and potentially turn vast stretches of Earth's food crops 48:54.333 --> 48:58.866 align:left position:22.5% line:83% size:67.5% into a carbon-storing juggernaut. 48:58.866 --> 49:00.600 align:left position:25% line:89% size:65% (indistinct talking) 49:00.600 --> 49:02.500 align:left position:27.5% line:89% size:62.5% Can you grab that? 49:02.500 --> 49:03.766 align:left position:40% line:83% size:50% SILVER: We now have ten years of data 49:03.766 --> 49:08.533 align:left position:27.5% line:83% size:62.5% showing that just a one-time dusting of compost 49:08.533 --> 49:10.033 align:left position:22.5% line:89% size:67.5% onto the soil surface 49:10.033 --> 49:13.766 align:left position:15% line:83% size:75% can have a long-term impact on plant growth 49:13.766 --> 49:17.533 align:left position:15% line:83% size:75% and increase carbon storage in soils. 49:17.533 --> 49:19.566 align:left position:37.5% line:5% size:52.5% NARRATOR: Whendee's research shows that 49:19.566 --> 49:21.533 align:left position:17.5% line:5% size:72.5% a single layer of compost 49:21.533 --> 49:25.666 align:left position:17.5% line:5% size:72.5% can increase plant growth by up to 78% 49:25.666 --> 49:31.133 align:left position:15% line:83% size:75% and increase soil carbon by up to 37% for three years. 49:33.300 --> 49:34.800 align:left position:40% line:83% size:50% SILVER: The real challenge is 49:34.800 --> 49:38.300 align:left position:10% line:83% size:80% to extrapolate from little tiny soil samples in the field 49:38.300 --> 49:43.733 align:left position:30% line:83% size:60% to big chunks of California or the globe. 49:43.733 --> 49:46.066 align:left position:20% line:89% size:70% That's a huge challenge. 49:46.066 --> 49:49.233 align:left position:45% line:89% size:45% ♪ ♪ 49:52.133 --> 49:54.200 align:left position:37.5% line:83% size:52.5% NARRATOR: As the hunt for solutions 49:54.200 --> 49:56.666 align:left position:10% line:89% size:80% continues in the decades ahead, 49:56.666 --> 49:59.100 align:left position:12.5% line:89% size:77.5% stopping our emissions remains 49:59.100 --> 50:03.166 align:left position:17.5% line:83% size:72.5% the most urgent challenge of today. 50:03.166 --> 50:06.833 align:left position:42.5% line:77% size:47.5% KEITH: If we really didn't do anything to limit carbon emissions, 50:06.833 --> 50:10.633 align:left position:12.5% line:83% size:77.5% we would have climate changes as big as the changes 50:10.633 --> 50:13.233 align:left position:30% line:83% size:60% from the glacial to interglacial state 50:13.233 --> 50:15.100 align:left position:35% line:83% size:55% and do that in one human lifetime, 50:15.100 --> 50:17.033 align:left position:15% line:89% size:75% with huge potential impacts. 50:17.033 --> 50:18.466 align:left position:15% line:89% size:75% The more of a mess we make, 50:18.466 --> 50:19.900 align:left position:25% line:83% size:65% the bigger of a mess we'll have to clean up. 50:21.700 --> 50:24.566 align:left position:22.5% line:89% size:67.5% We today get to decide 50:24.566 --> 50:27.933 align:left position:37.5% line:83% size:52.5% whether to continue along this path... 50:31.933 --> 50:33.966 align:left position:20% line:89% size:70% Or to dramatically shift 50:33.966 --> 50:38.166 align:left position:35% line:83% size:55% our economy off of coal, oil, and gas. 50:38.166 --> 50:41.133 align:left position:40% line:77% size:50% EXTAVOR: Every big transformative solution starts small. 50:41.133 --> 50:43.933 align:left position:32.5% line:83% size:57.5% It starts with a couple of people talking. 50:43.933 --> 50:45.166 align:left position:17.5% line:5% size:72.5% They make a small version, 50:45.166 --> 50:46.866 align:left position:15% line:5% size:75% they make a bigger version, more people pile in. 50:49.466 --> 50:51.066 align:left position:40% line:83% size:50% ZOHNER: This is one solution, 50:51.066 --> 50:53.000 align:left position:35% line:83% size:55% but we need thousands of solutions 50:53.000 --> 50:54.966 align:left position:25% line:83% size:65% if we want to tackle climate change. 50:54.966 --> 50:57.300 align:left position:40% line:83% size:50% SILVER: There's no one magic 50:57.300 --> 50:59.333 align:left position:32.5% line:83% size:57.5% silver bullet that will solve this problem. 50:59.333 --> 51:03.000 align:left position:42.5% line:83% size:47.5% SINHA: The main challenge that we have 51:03.000 --> 51:05.400 align:left position:17.5% line:83% size:72.5% is that these transitions don't happen overnight. 51:06.533 --> 51:09.066 align:left position:27.5% line:83% size:62.5% SNAEBJORNSDOTTIR: We have the tools already, 51:09.066 --> 51:10.933 align:left position:32.5% line:83% size:57.5% but we really have to start moving. 51:12.766 --> 51:14.900 align:left position:40% line:77% size:50% DENNING: We need better transportation systems. 51:14.900 --> 51:16.833 align:left position:25% line:83% size:65% We need solar power and wind power 51:16.833 --> 51:19.966 align:left position:30% line:83% size:60% and water power, and probably nuclear power. 51:19.966 --> 51:21.733 align:left position:20% line:89% size:70% We need to plant trees. 51:21.733 --> 51:23.433 align:left position:37.5% line:83% size:52.5% We need to manage our farms better. 51:23.433 --> 51:25.433 align:left position:15% line:89% size:75% We need direct air capture. 51:25.433 --> 51:27.533 align:left position:40% line:83% size:50% I think we probably need it all. 51:29.800 --> 51:32.733 align:left position:42.5% line:77% size:47.5% LONG: We have to start really looking at what can scale up 51:32.733 --> 51:37.400 align:left position:25% line:83% size:65% and be maintained-- for decades, if not centuries. 51:37.400 --> 51:39.166 align:left position:17.5% line:89% size:72.5% That's the challenge here. 51:39.166 --> 51:41.100 align:left position:35% line:83% size:55% But it's an incredibly important challenge. 51:41.100 --> 51:44.766 align:left position:45% line:89% size:45% ♪ ♪ 51:44.766 --> 51:46.000 align:left position:40% line:83% size:50% PACALA: 15 years ago, 51:46.000 --> 51:48.033 align:left position:10% line:89% size:80% no one would have predicted that 51:48.033 --> 51:51.600 align:left position:17.5% line:83% size:72.5% the emissions in developed countries around the world 51:51.600 --> 51:53.200 align:left position:27.5% line:89% size:62.5% would be dropping. 51:55.333 --> 51:56.700 align:left position:25% line:89% size:65% Not fast enough yet, 51:56.700 --> 51:59.100 align:left position:22.5% line:89% size:67.5% but that gives me hope 51:59.100 --> 52:01.066 align:left position:12.5% line:89% size:77.5% and should give everyone hope 52:01.066 --> 52:05.300 align:left position:22.5% line:83% size:67.5% that with the combined might of human ingenuity, 52:05.300 --> 52:07.033 align:left position:30% line:83% size:60% we can actually solve this problem. 52:07.033 --> 52:10.000 align:left position:45% line:89% size:45% ♪ ♪ 52:32.233 --> 52:37.866 align:left position:45% line:5% size:45% ♪ ♪ 52:48.133 --> 52:52.366 align:left position:12.5% line:5% size:77.5% To order this program on DVD, visit ShopPBS 52:52.366 --> 52:55.666 align:left position:20% line:5% size:70% or call 1-800-PLAY-PBS. 52:55.666 --> 52:58.400 align:left position:10% line:5% size:80% Episodes of "NOVA" are available with Passport. 52:58.400 --> 53:02.000 align:left position:20% line:5% size:70% "NOVA" is also available on Amazon Prime Video. 53:02.000 --> 53:07.100 align:left position:45% line:5% size:45% ♪ ♪ 53:14.500 --> 53:19.600 align:left position:45% line:5% size:45% ♪ ♪