JUDY WOODRUFF: In his remarks to
global leaders today, President
Biden said that climate change

is -- quote -- "ravaging the world."

That message is likely to be
delivered repeatedly at the U.N.
summit on climate change. Leaders,

researchers and activists all
say that humans are at a tipping
point to reduce emissions

and pressed the need for
meaningful action. But getting
commitments that translate to

real change is no small lift.

William Brangham reports on the stakes of
this summit.

WILLIAM BRANGHAM: In the small
Belgian town of Pepinster,
heavy machinery finishes what

the floodwaters started.

CAMILLE BRISBOIS, Belgium
(through translator): This
situation, it's difficult for me.

WILLIAM BRANGHAM: Camille
Brisbois knows his home is next.
It's the only house he's ever

known.

CAMILLE BRISBOIS (through
translator): I'm sentimental and
emotional. I was born in this

house on December 5, 1946.

WILLIAM BRANGHAM: It's pain
that was shared across Belgium
and Germany this summer, where

catastrophic floods killed more than 200.

Six thousand miles away, in
the Philippines, 61-year-old
Luzviminda Tayson fears she and

her family will face a similar fate, their
home swept away in a flood.

LUZVIMINDA TAYSON, Flood Evacuee
(through translator): The
monsoon rains are terrifying,

so we decided to evacuate
early. In the last typhoon, it
was difficult to get out. This

time, we didn't want the waters
to rise and be caught in it again.

WILLIAM BRANGHAM: Across the
Pacific Ocean, that same month,
friends gathered in Olympia,

Washington, to mourn the death
of Barnett Moss, one of the
hundreds who died in a brutal

heat wave.

MARY VAN VERST, Friend of
Barnett Moss: I brought extra
water and implored him to drink

it. I could tell he was
gravely affected by the heat.

WILLIAM BRANGHAM: Just south
of them, on the same coast,
in the same summer, the Caldor

Fire took Chris Sheean's home.

CHRIS SHEEAN, Fire Victim: Everything that
we owned, everything that we have built is

gone. The only thing that's left standing
is a chimney.

WILLIAM BRANGHAM: Four lives
among millions more distorted
and lost this year alone from

the impacts of climate change.

A warming atmosphere isn't the sole cause
of these disasters, but the evidence grows

clearer every day that fossil
fuel emissions make these
calamities more frequent, more

severe, more deadly.

MAN: I'm delighted that so many of
you have joined us here in Glasgow.

WILLIAM BRANGHAM: This is what's
facing leaders and negotiators
from nearly 200 countries

over the next two weeks in
Glasgow. Can those emissions be
curtailed? And can it be done

in time to avoid the worst
outcomes of climate change?

DR. KIM COBB, Climate Scientist,
Georgia Institute of Technology:
There's just a huge amount

at stake this fall. It's almost
hard to put into words, because
the burden on these policy-makers

could not be any greater.

WILLIAM BRANGHAM: Dr. Kim Cobb
is a climate scientist at the
Georgia Institute of Technology.

She was one of the lead authors
on a recent U.N. climate
report, which showed emissions

rising much faster than
previously known. She says these
COP 26 negotiations could be

historic.

DR. KIM COBB: This is something that is a
clarion call for our generation and future

generations for centuries to
come. Really, we're going to
be deciding what futures we're

bringing down upon ourselves, largely over
the next decade.

And, in part, that can be
distilled to this most historic
year of international ambition,

or lack thereof.

WILLIAM BRANGHAM: Back in 2015,
in the Paris agreement, 196
nations pledged to reduce their

emissions enough to keep
warming below an additional 2
degrees Celsius compared to the

preindustrial era.

The planet has already warmed
over one degree since the 19th
century. The hope in Paris

was to keep warming to just 1.5
degrees. Beyond that threshold,
scientists say the punishing

and lethal effects of climate change will
only get worse.

Here's how, back in 2015,
Princeton University's Michael
Oppenheimer stressed the urgency:

MICHAEL OPPENHEIMER, Professor
of Geosciences and International
Affairs, Princeton University:

If we don't start with rapid
emissions reductions and substantial
emissions reductions, that

we will pass a danger point,
beyond which the consequences
for many people and countries

on Earth will simply become
unacceptable and eventually disastrous.

WILLIAM BRANGHAM: At the
conclusion of the Paris talks,
President Obama expressed optimism

that the world understood the severity of
the crisis and was acting.

BARACK OBAMA, Former President
of the United States: I think
we're going to solve it. I

think the issue is just going
to be the pace, and how much
damage is done before we are

able to fully apply the brakes.

WILLIAM BRANGHAM: But in the
six years since, the world has
only stepped on the gas. Apart

from a brief dip during the
early days of the pandemic,
global emissions have continued

to set records.

More than half of all the
carbon that's been put in the
atmosphere was done in just the

last 30 years. Global temperatures
have also continued to rise.
The last seven years have

been the warmest seven years on record.

ANTONIO GUTERRES, United Nations
Secretary-General: It's time to
say, enough. Enough of brutalizing

biodiversity. Enough of
killing ourselves with carbon.
Enough of treating nature like

a toilet. Enough of burning
and drilling and mining our
way deeper. We are digging our

own graves.

WILLIAM BRANGHAM: A report
released by the U.N. last week
said that, at this pace, the

world will blow past those Paris
targets and hit 2.7 degrees
Celsius of warming by the

end of the century.

DR. KIM COBB: It's really
important to realize just how
little we have tipped the scales

in our global climate system,
and how these have translated
into the devastating effects

we're seeing today.

We have warmed 1.1 degrees
Celsius since the preindustrial
era. To double or triple the

kinds of impacts that we're seeing, that's
a 2 or 3 degree Celsius world, and that is

not a world that would be
remotely recognizable to those of
us sitting here today, already

reeling from the effects of
a 1.1 degree Celsius world.

WILLIAM BRANGHAM: Unrecognizable to us?

DR. KIM COBB: Yes.

WILLIAM BRANGHAM: Right now,
climate change is forcing
massive migrations. One recent

analysis said climate-related
events drive twice as many
people from their homes as war

and violence.

Two weeks ago, the Pentagon,
the White House, DHS, and the
director of national intelligence

all echoed this concern that
-- quote -- "The climate crisis
is reshaping our world" and

that these migrations could trigger
political instability and conflict.

Providing aid to these vulnerable nations
will be another main topic in Glasgow. The

world's major polluters have
failed to fully deliver a
promised $100 billion yearly fund

to help these countries adapt and survive
in a warming world.

GRETA THUNBERG, Climate Activist:
Build back better, blah, blah,
blah. Green economy, blah,

blah, blah. Net zero by 2050, blah, blah,
blah.

WILLIAM BRANGHAM: In the
lead-up to Glasgow, the global
climate movement has continued

to press for action, including
Swedish teenager Greta Thunberg,
who's been excoriating world

leaders for unkept promises.

GRETA THUNBERG: This is all
we hear from our so-called
leaders, words, words that sound

great, but so far have led to no action.

WOMAN: We have to get strong
commitments to reduce emissions by 2030.

WILLIAM BRANGHAM: As negotiators
in Glasgow hope to forge
the safest possible future,

those on the front lines
continue to suffer the very ugly
present of a warming world.

JUDY WOODRUFF: And William joins me now.

And what a stark picture that
report is painting, William.

So these meetings, a huge
gathering of leaders and activists,
it goes for two weeks. What

is expected is going to come
out of this in practical terms?

WILLIAM BRANGHAM: Well, it is
important to know Glasgow is a
continuation of this process.

Paris, as we heard, set this
it goal of, let's do everything
we can to keep warming of the

planet from going above an
additional 1.5 degrees Celsius.
This meeting in Glasgow is

sort of a check-in of sorts for
all the nations to come together
and say, are we cutting emissions

enough to stay under that threshold?

It's sort of a way to stiffen
the global spine for more action.
One complication on all of

this, though, is that all of
these pledges are voluntary.
There is no built-in enforcement

mechanism. No one should be waiting for a
treaty or pact to be signed at the end of

all of this.

But it is really what happens
after Glasgow, in the weeks
and months and year after yard

afterwards, that we will know whether
these countries took themselves seriously.

JUDY WOODRUFF: So, how likely
is it that we are going to
see some measure of success,

some semblance of real success?

WILLIAM BRANGHAM: Well, there
is real hope, but there are
a lot of dark clouds on the

horizon.

The U.S.' position in particular,
there is no doubt that Joe
Biden is in Glasgow right

now with a weakened hand. Last
week, a major climate tool
was taken out of his toolbox

by Joe Manchin. The Build
Back Better has some elements
that are still potent climate

tools. But we know that Manchin
is still dubious about that.

So it's very difficult for the
United States to cajole other
nations and say, act boldly

on this issue, when we have a hard
time doing it here in the U.S.

Same issue also applies to the
other major emitters, China,
India, Brazil. Their leaders

are either not at Glasgow or their pledges
thus far have not gotten us anywhere near

where we need to be.

The important thing to take
away from all of this is that
the gulf between what we know

needs to be done and what
nations have pledged to do is
unbelievably vast. And narrowing

that chasm is the whole goal.

JUDY WOODRUFF: Well, we are
going to be watching it.

You are going to Glasgow next
week. You're going to be reporting
from there for us through

the end of the two-week period.

Thank you, William.

WILLIAM BRANGHAM: You're welcome, Judy.