0:00:00.000,0:00:02.000
What do I know

0:00:02.000,0:00:04.000
that would cause me,

0:00:04.000,0:00:06.000
a reticent, Midwestern scientist,

0:00:06.000,0:00:09.000
to get myself arrested

0:00:09.000,0:00:12.000
in front of the White House protesting?

0:00:12.000,0:00:14.000
And what would you do

0:00:14.000,0:00:16.000
if you knew what I know?

0:00:16.000,0:00:20.000
Let's start with how I got to this point.

0:00:20.000,0:00:22.000
I was lucky to grow up

0:00:22.000,0:00:25.000
at a time when it was not difficult

0:00:25.000,0:00:27.000
for the child of a tenant farmer

0:00:27.000,0:00:29.000
to make his way to the state university.

0:00:29.000,0:00:32.000
And I was really lucky

0:00:32.000,0:00:34.000
to go to the University of Iowa

0:00:34.000,0:00:37.000
where I could study under Professor James Van Allen

0:00:37.000,0:00:39.000
who built instruments

0:00:39.000,0:00:41.000
for the first U.S. satellites.

0:00:41.000,0:00:44.000
Professor Van Allen told me

0:00:44.000,0:00:47.000
about observations of Venus,

0:00:47.000,0:00:49.000
that there was intense microwave radiation.

0:00:49.000,0:00:52.000
Did it mean that Venus had an ionosphere?

0:00:52.000,0:00:54.000
Or was Venus extremely hot?

0:00:54.000,0:00:56.000
The right answer,

0:00:56.000,0:01:01.000
confirmed by the Soviet Venera spacecraft,

0:01:01.000,0:01:04.000
was that Venus was very hot --

0:01:04.000,0:01:06.000
900 degrees Fahrenheit.

0:01:06.000,0:01:08.000
And it was kept hot

0:01:08.000,0:01:11.000
by a thick carbon dioxide atmosphere.

0:01:11.000,0:01:13.000
I was fortunate to join NASA

0:01:13.000,0:01:15.000
and successfully propose

0:01:15.000,0:01:17.000
an experiment to fly to Venus.

0:01:17.000,0:01:20.000
Our instrument took this image

0:01:20.000,0:01:22.000
of the veil of Venus,

0:01:22.000,0:01:24.000
which turned out to be

0:01:24.000,0:01:27.000
a smog of sulfuric acid.

0:01:27.000,0:01:30.000
But while our instrument was being built,

0:01:30.000,0:01:32.000
I became involved in calculations

0:01:32.000,0:01:34.000
of the greenhouse effect

0:01:34.000,0:01:36.000
here on Earth,

0:01:36.000,0:01:38.000
because we realized

0:01:38.000,0:01:41.000
that our atmospheric composition was changing.

0:01:41.000,0:01:43.000
Eventually, I resigned

0:01:43.000,0:01:45.000
as principal investigator

0:01:45.000,0:01:47.000
on our Venus experiment

0:01:47.000,0:01:50.000
because a planet changing before our eyes

0:01:50.000,0:01:52.000
is more interesting and important.

0:01:52.000,0:01:55.000
Its changes will affect all of humanity.

0:01:55.000,0:01:57.000
The greenhouse effect had been well understood

0:01:57.000,0:01:59.000
for more than a century.

0:01:59.000,0:02:01.000
British physicist John Tyndall,

0:02:01.000,0:02:03.000
in the 1850's,

0:02:03.000,0:02:05.000
made laboratory measurements

0:02:05.000,0:02:07.000
of the infrared radiation,

0:02:07.000,0:02:09.000
which is heat.

0:02:09.000,0:02:12.000
And he showed that gasses such as CO2 absorb heat,

0:02:12.000,0:02:15.000
thus acting like a blanket

0:02:15.000,0:02:17.000
warming Earth's surface.

0:02:17.000,0:02:19.000
I worked with other scientists

0:02:19.000,0:02:23.000
to analyze Earth climate observations.

0:02:23.000,0:02:25.000
In 1981,

0:02:25.000,0:02:28.000
we published an article in Science magazine

0:02:28.000,0:02:30.000
concluding that observed warming

0:02:30.000,0:02:32.000
of 0.4 degrees Celsius

0:02:32.000,0:02:34.000
in the prior century

0:02:34.000,0:02:36.000
was consistent with the greenhouse effect

0:02:36.000,0:02:38.000
of increasing CO2.

0:02:38.000,0:02:41.000
That Earth would likely warm in the 1980's,

0:02:41.000,0:02:43.000
and warming would exceed

0:02:43.000,0:02:45.000
the noise level of random weather

0:02:45.000,0:02:47.000
by the end of the century.

0:02:47.000,0:02:50.000
We also said that the 21st century

0:02:50.000,0:02:52.000
would see shifting climate zones,

0:02:52.000,0:02:54.000
creation of drought-prone regions

0:02:54.000,0:02:56.000
in North America and Asia,

0:02:56.000,0:02:59.000
erosion of ice sheets, rising sea levels

0:02:59.000,0:03:02.000
and opening of the fabled Northwest Passage.

0:03:02.000,0:03:04.000
All of these impacts

0:03:04.000,0:03:06.000
have since either happened

0:03:06.000,0:03:08.000
or are now well under way.

0:03:08.000,0:03:12.000
That paper was reported on the front page of the New York Times

0:03:12.000,0:03:14.000
and led to me testifying to Congress

0:03:14.000,0:03:16.000
in the 1980's,

0:03:16.000,0:03:19.000
testimony in which I emphasized

0:03:19.000,0:03:22.000
that global warming increases both extremes

0:03:22.000,0:03:25.000
of the Earth's water cycle.

0:03:25.000,0:03:27.000
Heatwaves and droughts on one hand,

0:03:27.000,0:03:29.000
directly from the warming,

0:03:29.000,0:03:31.000
but also, because a warmer atmosphere

0:03:31.000,0:03:33.000
holds more water vapor

0:03:33.000,0:03:35.000
with its latent energy,

0:03:35.000,0:03:37.000
rainfall will become

0:03:37.000,0:03:39.000
in more extreme events.

0:03:39.000,0:03:42.000
There will be stronger storms and greater flooding.

0:03:42.000,0:03:45.000
Global warming hoopla

0:03:45.000,0:03:47.000
became time-consuming

0:03:47.000,0:03:49.000
and distracted me from doing science --

0:03:49.000,0:03:51.000
partly because I had complained

0:03:51.000,0:03:54.000
that the White House altered my testimony.

0:03:54.000,0:03:56.000
So I decided to go back

0:03:56.000,0:03:58.000
to strictly doing science

0:03:58.000,0:04:02.000
and leave the communication to others.

0:04:02.000,0:04:05.000
By 15 years later,

0:04:05.000,0:04:08.000
evidence of global warming was much stronger.

0:04:08.000,0:04:11.000
Most of the things mentioned in our 1981 paper

0:04:11.000,0:04:13.000
were facts.

0:04:13.000,0:04:16.000
I had the privilege to speak twice

0:04:16.000,0:04:18.000
to the president's climate task force.

0:04:18.000,0:04:21.000
But energy policies continued to focus

0:04:21.000,0:04:24.000
on finding more fossil fuels.

0:04:24.000,0:04:27.000
By then we had two grandchildren,

0:04:27.000,0:04:29.000
Sophie and Connor.

0:04:29.000,0:04:31.000
I decided

0:04:31.000,0:04:33.000
that I did not want them in the future

0:04:33.000,0:04:35.000
to say, "Opa understood what was happening,

0:04:35.000,0:04:37.000
but he didn't make it clear."

0:04:37.000,0:04:40.000
So I decided to give a public talk

0:04:40.000,0:04:43.000
criticizing the lack of an appropriate energy policy.

0:04:43.000,0:04:46.000
I gave the talk at the University of Iowa in 2004

0:04:46.000,0:04:49.000
and at the 2005 meeting

0:04:49.000,0:04:52.000
of the American Geophysical Union.

0:04:52.000,0:04:54.000
This led to calls

0:04:54.000,0:04:56.000
from the White House to NASA headquarters

0:04:56.000,0:04:59.000
and I was told that I could not give any talks or speak with the media

0:04:59.000,0:05:02.000
without prior explicit approval

0:05:02.000,0:05:05.000
by NASA headquarters.

0:05:05.000,0:05:07.000
After I informed the New York Times

0:05:07.000,0:05:09.000
about these restrictions,

0:05:09.000,0:05:12.000
NASA was forced to end the censorship.

0:05:12.000,0:05:14.000
But there were consequences.

0:05:14.000,0:05:16.000
I had been using the first line

0:05:16.000,0:05:18.000
of the NASA mission statement,

0:05:18.000,0:05:21.000
"To understand and protect the home planet,"

0:05:21.000,0:05:23.000
to justify my talks.

0:05:23.000,0:05:25.000
Soon the first line of the mission statement

0:05:25.000,0:05:29.000
was deleted, never to appear again.

0:05:29.000,0:05:31.000
Over the next few years

0:05:31.000,0:05:33.000
I was drawn more and more

0:05:33.000,0:05:36.000
into trying to communicate the urgency

0:05:36.000,0:05:39.000
of a change in energy policies,

0:05:39.000,0:05:42.000
while still researching the physics of climate change.

0:05:42.000,0:05:45.000
Let me describe the most important conclusion from the physics --

0:05:45.000,0:05:48.000
first, from Earth's energy balance

0:05:48.000,0:05:52.000
and, second, from Earth's climate history.

0:05:52.000,0:05:54.000
Adding CO2 to the air

0:05:54.000,0:05:57.000
is like throwing another blanket on the bed.

0:05:57.000,0:06:00.000
It reduces Earth's heat radiation to space,

0:06:00.000,0:06:03.000
so there's a temporary energy imbalance.

0:06:03.000,0:06:05.000
More energy is coming in

0:06:05.000,0:06:07.000
than going out,

0:06:07.000,0:06:09.000
until Earth warms up enough

0:06:09.000,0:06:11.000
to again radiate to space

0:06:11.000,0:06:13.000
as much energy as it absorbs from the Sun.

0:06:13.000,0:06:15.000
So the key quantity

0:06:15.000,0:06:18.000
is Earth's energy imbalance.

0:06:18.000,0:06:20.000
Is there more energy coming in

0:06:20.000,0:06:22.000
than going out?

0:06:22.000,0:06:25.000
If so, more warming is in the pipeline.

0:06:25.000,0:06:29.000
It will occur without adding any more greenhouse gasses.

0:06:29.000,0:06:31.000
Now finally,

0:06:31.000,0:06:35.000
we can measure Earth's energy imbalance precisely

0:06:35.000,0:06:37.000
by measuring the heat content

0:06:37.000,0:06:40.000
in Earth's heat reservoirs.

0:06:40.000,0:06:43.000
The biggest reservoir, the ocean, was the least well measured,

0:06:43.000,0:06:46.000
until more than 3,000 Argo floats

0:06:46.000,0:06:49.000
were distributed around the world's ocean.

0:06:49.000,0:06:51.000
These floats reveal

0:06:51.000,0:06:53.000
that the upper half of the ocean

0:06:53.000,0:06:56.000
is gaining heat at a substantial rate.

0:06:56.000,0:06:59.000
The deep ocean is also gaining heat at a smaller rate,

0:06:59.000,0:07:01.000
and energy is going

0:07:01.000,0:07:04.000
into the net melting of ice all around the planet.

0:07:04.000,0:07:07.000
And the land, to depths of tens of meters,

0:07:07.000,0:07:09.000
is also warming.

0:07:09.000,0:07:12.000
The total energy imbalance now

0:07:12.000,0:07:16.000
is about six-tenths of a watt per square meter.

0:07:16.000,0:07:18.000
That may not sound like much,

0:07:18.000,0:07:21.000
but when added up over the whole world, it's enormous.

0:07:21.000,0:07:24.000
It's about 20 times greater

0:07:24.000,0:07:27.000
than the rate of energy use by all of humanity.

0:07:27.000,0:07:29.000
It's equivalent to exploding

0:07:29.000,0:07:35.000
400,000 Hiroshima atomic bombs per day

0:07:35.000,0:07:38.000
365 days per year.

0:07:38.000,0:07:40.000
That's how much extra energy

0:07:40.000,0:07:42.000
Earth is gaining each day.

0:07:42.000,0:07:44.000
This imbalance,

0:07:44.000,0:07:47.000
if we want to stabilize climate,

0:07:47.000,0:07:49.000
means that we must reduce CO2

0:07:49.000,0:07:52.000
from 391 ppm, parts per million,

0:07:52.000,0:07:55.000
back to 350 ppm.

0:07:55.000,0:07:58.000
That is the change needed to restore energy balance

0:07:58.000,0:08:00.000
and prevent further warming.

0:08:00.000,0:08:03.000
Climate change deniers argue

0:08:03.000,0:08:06.000
that the Sun is the main cause of climate change.

0:08:06.000,0:08:09.000
But the measured energy imbalance occurred

0:08:09.000,0:08:13.000
during the deepest solar minimum in the record,

0:08:13.000,0:08:17.000
when the Sun's energy reaching Earth was least.

0:08:17.000,0:08:20.000
Yet, there was more energy coming in than going out.

0:08:20.000,0:08:23.000
This shows that the effect of the Sun's variations on climate

0:08:23.000,0:08:26.000
is overwhelmed by the increasing greenhouse gasses,

0:08:26.000,0:08:29.000
mainly from burning fossil fuels.

0:08:29.000,0:08:32.000
Now consider Earth's climate history.

0:08:32.000,0:08:34.000
These curves for global temperature,

0:08:34.000,0:08:37.000
atmospheric CO2 and sea level

0:08:37.000,0:08:40.000
were derived from ocean cores and Antarctic ice cores,

0:08:40.000,0:08:42.000
from ocean sediments and snowflakes

0:08:42.000,0:08:45.000
that piled up year after year

0:08:45.000,0:08:47.000
over 800,000 years

0:08:47.000,0:08:49.000
forming a two-mile thick ice sheet.

0:08:49.000,0:08:52.000
As you see, there's a high correlation

0:08:52.000,0:08:55.000
between temperature, CO2 and sea level.

0:08:55.000,0:08:57.000
Careful examination shows

0:08:57.000,0:08:59.000
that the temperature changes

0:08:59.000,0:09:01.000
slightly lead the CO2 changes

0:09:01.000,0:09:04.000
by a few centuries.

0:09:04.000,0:09:07.000
Climate change deniers like to use this fact

0:09:07.000,0:09:10.000
to confuse and trick the public

0:09:10.000,0:09:13.000
by saying, "Look, the temperature causes CO2 to change,

0:09:13.000,0:09:15.000
not vice versa."

0:09:15.000,0:09:17.000
But that lag

0:09:17.000,0:09:20.000
is exactly what is expected.

0:09:20.000,0:09:23.000
Small changes in Earth's orbit

0:09:23.000,0:09:26.000
that occur over tens to hundreds of thousands of years

0:09:26.000,0:09:28.000
alter the distribution

0:09:28.000,0:09:30.000
of sunlight on Earth.

0:09:30.000,0:09:32.000
When there is more sunlight

0:09:32.000,0:09:35.000
at high latitudes in summer, ice sheets melt.

0:09:35.000,0:09:37.000
Shrinking ice sheets

0:09:37.000,0:09:39.000
make the planet darker,

0:09:39.000,0:09:41.000
so it absorbs more sunlight

0:09:41.000,0:09:43.000
and becomes warmer.

0:09:43.000,0:09:45.000
A warmer ocean releases CO2,

0:09:45.000,0:09:48.000
just as a warm Coca-Cola does.

0:09:48.000,0:09:51.000
And more CO2 causes more warming.

0:09:51.000,0:09:54.000
So CO2, methane, and ice sheets

0:09:54.000,0:09:56.000
were feedbacks

0:09:56.000,0:09:59.000
that amplified global temperature change

0:09:59.000,0:10:02.000
causing these ancient climate oscillations to be huge,

0:10:02.000,0:10:05.000
even though the climate change was initiated

0:10:05.000,0:10:07.000
by a very weak forcing.

0:10:07.000,0:10:09.000
The important point

0:10:09.000,0:10:11.000
is that these same amplifying feedbacks

0:10:11.000,0:10:13.000
will occur today.

0:10:13.000,0:10:15.000
The physics does not change.

0:10:15.000,0:10:17.000
As Earth warms,

0:10:17.000,0:10:20.000
now because of extra CO2 we put in the atmosphere,

0:10:20.000,0:10:22.000
ice will melt,

0:10:22.000,0:10:24.000
and CO2 and methane will be released

0:10:24.000,0:10:27.000
by warming ocean and melting permafrost.

0:10:27.000,0:10:30.000
While we can't say exactly how fast

0:10:30.000,0:10:33.000
these amplifying feedbacks will occur,

0:10:33.000,0:10:36.000
it is certain they will occur,

0:10:36.000,0:10:38.000
unless we stop the warming.

0:10:38.000,0:10:40.000
There is evidence

0:10:40.000,0:10:43.000
that feedbacks are already beginning.

0:10:43.000,0:10:45.000
Precise measurements

0:10:45.000,0:10:47.000
by GRACE, the gravity satellite,

0:10:47.000,0:10:50.000
reveal that both Greenland and Antarctica

0:10:50.000,0:10:52.000
are now losing mass,

0:10:52.000,0:10:55.000
several hundred cubic kilometers per year.

0:10:55.000,0:10:57.000
And the rate has accelerated

0:10:57.000,0:10:59.000
since the measurements began

0:10:59.000,0:11:01.000
nine years ago.

0:11:01.000,0:11:03.000
Methane is also beginning

0:11:03.000,0:11:06.000
to escape from the permafrost.

0:11:06.000,0:11:08.000
What sea level rise

0:11:08.000,0:11:10.000
can we look forward to?

0:11:10.000,0:11:13.000
The last time CO2 was 390 ppm,

0:11:13.000,0:11:15.000
today's value,

0:11:15.000,0:11:17.000
sea level was higher

0:11:17.000,0:11:20.000
by at least 15 meters, 50 feet.

0:11:20.000,0:11:22.000
Where you are sitting now

0:11:22.000,0:11:24.000
would be under water.

0:11:24.000,0:11:27.000
Most estimates are that, this century,

0:11:27.000,0:11:29.000
we will get at least one meter.

0:11:29.000,0:11:31.000
I think it will be more

0:11:31.000,0:11:33.000
if we keep burning fossil fuels,

0:11:33.000,0:11:36.000
perhaps even five meters, which is 18 feet,

0:11:36.000,0:11:39.000
this century or shortly thereafter.

0:11:39.000,0:11:41.000
The important point

0:11:41.000,0:11:44.000
is that we will have started a process

0:11:44.000,0:11:47.000
that is out of humanity's control.

0:11:47.000,0:11:50.000
Ice sheets would continue to disintegrate for centuries.

0:11:50.000,0:11:52.000
There would be no stable shoreline.

0:11:52.000,0:11:55.000
The economic consequences are almost unthinkable.

0:11:55.000,0:11:59.000
Hundreds of New Orleans-like devastations

0:11:59.000,0:12:01.000
around the world.

0:12:01.000,0:12:03.000
What may be more reprehensible,

0:12:03.000,0:12:05.000
if climate denial continues,

0:12:05.000,0:12:07.000
is extermination of species.

0:12:07.000,0:12:09.000
The monarch butterfly

0:12:09.000,0:12:14.000
could be one of the 20 to 50 percent of all species

0:12:14.000,0:12:17.000
that the Intergovernmental Panel on Climate Change estimates

0:12:17.000,0:12:19.000
will be ticketed for extinction

0:12:19.000,0:12:21.000
by the end of the century

0:12:21.000,0:12:25.000
if we stay on business-as-usual fossil fuel use.

0:12:25.000,0:12:28.000
Global warming is already affecting people.

0:12:28.000,0:12:30.000
The Texas, Oklahoma, Mexico

0:12:30.000,0:12:33.000
heatwave and drought last year,

0:12:33.000,0:12:35.000
Moscow the year before

0:12:35.000,0:12:37.000
and Europe in 2003,

0:12:37.000,0:12:40.000
were all exceptional events,

0:12:40.000,0:12:44.000
more than three standard deviations outside the norm.

0:12:44.000,0:12:46.000
Fifty years ago,

0:12:46.000,0:12:48.000
such anomalies

0:12:48.000,0:12:50.000
covered only two- to three-tenths

0:12:50.000,0:12:52.000
of one percent of the land area.

0:12:52.000,0:12:54.000
In recent years,

0:12:54.000,0:12:56.000
because of global warming,

0:12:56.000,0:12:58.000
they now cover about 10 percent --

0:12:58.000,0:13:01.000
an increase by a factor of 25 to 50.

0:13:01.000,0:13:04.000
So we can say with a high degree of confidence

0:13:04.000,0:13:06.000
that the severe Texas and Moscow heatwaves

0:13:06.000,0:13:08.000
were not natural;

0:13:08.000,0:13:11.000
they were caused by global warming.

0:13:11.000,0:13:13.000
An important impact,

0:13:13.000,0:13:15.000
if global warming continues,

0:13:15.000,0:13:18.000
will be on the breadbasket of our nation and the world,

0:13:18.000,0:13:20.000
the Midwest and Great Plains,

0:13:20.000,0:13:23.000
which are expected to become prone to extreme droughts,

0:13:23.000,0:13:25.000
worse than the Dust Bowl,

0:13:25.000,0:13:27.000
within just a few decades,

0:13:27.000,0:13:31.000
if we let global warming continue.

0:13:31.000,0:13:34.000
How did I get dragged deeper and deeper

0:13:34.000,0:13:36.000
into an attempt to communicate,

0:13:36.000,0:13:39.000
giving talks in 10 countries, getting arrested,

0:13:39.000,0:13:41.000
burning up the vacation time

0:13:41.000,0:13:44.000
that I had accumulated over 30 years?

0:13:45.000,0:13:48.000
More grandchildren helped me along.

0:13:48.000,0:13:50.000
Jake is a super-positive,

0:13:50.000,0:13:53.000
enthusiastic boy.

0:13:53.000,0:13:55.000
Here at age two and a half years,

0:13:55.000,0:13:57.000
he thinks he can protect

0:13:57.000,0:14:00.000
his two and a half-day-old little sister.

0:14:00.000,0:14:02.000
It would be immoral

0:14:02.000,0:14:04.000
to leave these young people

0:14:04.000,0:14:06.000
with a climate system

0:14:06.000,0:14:08.000
spiraling out of control.

0:14:08.000,0:14:11.000
Now the tragedy about climate change

0:14:11.000,0:14:13.000
is that we can solve it

0:14:13.000,0:14:15.000
with a simple, honest approach

0:14:15.000,0:14:18.000
of a gradually rising carbon fee

0:14:18.000,0:14:20.000
collected from fossil fuel companies

0:14:20.000,0:14:24.000
and distributed 100 percent electronically

0:14:24.000,0:14:26.000
every month to all legal residents

0:14:26.000,0:14:28.000
on a per capita basis,

0:14:28.000,0:14:32.000
with the government not keeping one dime.

0:14:32.000,0:14:35.000
Most people would get more in the monthly dividend

0:14:35.000,0:14:37.000
than they'd pay in increased prices.

0:14:37.000,0:14:39.000
This fee and dividend

0:14:39.000,0:14:41.000
would stimulate the economy

0:14:41.000,0:14:43.000
and innovations,

0:14:43.000,0:14:45.000
creating millions of jobs.

0:14:45.000,0:14:47.000
It is the principal requirement

0:14:47.000,0:14:50.000
for moving us rapidly

0:14:50.000,0:14:52.000
to a clean energy future.

0:14:52.000,0:14:54.000
Several top economists

0:14:54.000,0:14:57.000
are coauthors on this proposition.

0:14:57.000,0:15:00.000
Jim DiPeso of Republicans for Environmental Protection

0:15:00.000,0:15:02.000
describes it thusly:

0:15:02.000,0:15:04.000
"Transparent. Market-based.

0:15:04.000,0:15:06.000
Does not enlarge government.

0:15:06.000,0:15:09.000
Leaves energy decisions to individual choices.

0:15:09.000,0:15:13.000
Sounds like a conservative climate plan."

0:15:13.000,0:15:17.000
But instead of placing a rising fee on carbon emissions

0:15:17.000,0:15:20.000
to make fossil fuels pay

0:15:20.000,0:15:22.000
their true cost to society,

0:15:22.000,0:15:25.000
our governments are forcing the public

0:15:25.000,0:15:28.000
to subsidize fossil fuels

0:15:28.000,0:15:31.000
by 400 to 500 billion dollars

0:15:31.000,0:15:33.000
per year worldwide,

0:15:33.000,0:15:36.000
thus encouraging extraction of every fossil fuel --

0:15:36.000,0:15:38.000
mountaintop removal,

0:15:38.000,0:15:40.000
longwall mining, fracking,

0:15:40.000,0:15:42.000
tar sands, tar shale,

0:15:42.000,0:15:45.000
deep ocean Arctic drilling.

0:15:45.000,0:15:47.000
This path, if continued,

0:15:47.000,0:15:50.000
guarantees that we will pass tipping points

0:15:50.000,0:15:52.000
leading to ice sheet disintegration

0:15:52.000,0:15:56.000
that will accelerate out of control of future generations.

0:15:56.000,0:15:58.000
A large fraction of species

0:15:58.000,0:16:00.000
will be committed to extinction.

0:16:00.000,0:16:02.000
And increasing intensity of droughts and floods

0:16:02.000,0:16:05.000
will severely impact breadbaskets of the world,

0:16:05.000,0:16:07.000
causing massive famines

0:16:07.000,0:16:10.000
and economic decline.

0:16:11.000,0:16:14.000
Imagine a giant asteroid

0:16:14.000,0:16:18.000
on a direct collision course with Earth.

0:16:18.000,0:16:20.000
That is the equivalent

0:16:20.000,0:16:22.000
of what we face now.

0:16:22.000,0:16:24.000
Yet, we dither,

0:16:24.000,0:16:26.000
taking no action

0:16:26.000,0:16:28.000
to divert the asteroid,

0:16:28.000,0:16:30.000
even though the longer we wait,

0:16:30.000,0:16:34.000
the more difficult and expensive it becomes.

0:16:34.000,0:16:36.000
If we had started in 2005,

0:16:36.000,0:16:39.000
it would have required emission reductions of three percent per year

0:16:39.000,0:16:42.000
to restore planetary energy balance

0:16:42.000,0:16:45.000
and stabilize climate this century.

0:16:45.000,0:16:47.000
If we start next year,

0:16:47.000,0:16:49.000
it is six percent per year.

0:16:49.000,0:16:52.000
If we wait 10 years, it is 15 percent per year --

0:16:52.000,0:16:54.000
extremely difficult and expensive,

0:16:54.000,0:16:57.000
perhaps impossible.

0:16:57.000,0:16:59.000
But we aren't even starting.

0:16:59.000,0:17:02.000
So now you know what I know

0:17:02.000,0:17:05.000
that is moving me to sound this alarm.

0:17:05.000,0:17:08.000
Clearly, I haven't gotten this message across.

0:17:08.000,0:17:11.000
The science is clear.

0:17:11.000,0:17:13.000
I need your help

0:17:13.000,0:17:15.000
to communicate the gravity and the urgency

0:17:15.000,0:17:17.000
of this situation

0:17:17.000,0:17:19.000
and its solutions

0:17:19.000,0:17:21.000
more effectively.

0:17:21.000,0:17:23.000
We owe it to our children and grandchildren.

0:17:23.000,0:17:25.000
Thank you.

0:17:25.000,0:17:30.000
(Applause)