AMNA NAWAZ: By almost any measure, 2019 was a year of especially sobering news about climate
change, not only because of new findings and grim warnings about what could happen, but
because some -- of some extreme weather events happening now.
It was also a year where a movement grew from the ground up to try and tackle the problem.
But, as Miles O'Brien explains, the call for action was often divorced from political reality.
His report tonight is part of our regular coverage of the Leading Edge of Science.
MILES O'BRIEN: When Apollo astronauts looked back at the tiny blue marble in the vast inky
void that we call home, they were awestruck by its beauty.
That, you might have predicted.
MIKE COLLINS, Former NASA Astronaut: But there was a surprising aspect.
Somehow, the Earth projected a feeling of fragility.
MILES O'BRIEN: Apollo 11 crew member Mike Collins.
MIKE COLLINS: If I had to describe just in one word what the Earth looked like from the
moon, I would say fragile.
MILES O'BRIEN: Fifty years later, the collision between that fragility and humanity's indifference
to it came closer to home, much closer.
When the final numbers come in, scientists predict 2019 will be the second or third hottest
year on record.
It means the past six years were the warmest six since humans started keeping track.
In Australia, they are feeling the heat like never before.
On December 18, the country logged its hottest day on record, a national average high of
107.4 degrees Fahrenheit.
Along with the heat came hundreds of wildfires fueled by drought-parched brush.
Wildfires once again ravaged California this year.
A quarter million acres burned.
In September, the remnants of Tropical Storm Imelda dumbed more than 43 inches of rain
in Texas.
The seventh wettest cyclone to hit the U.S. left $2 billion in damage behind.
And also in September, Category 5 Hurricane Dorian slow-rolled the Bahamas.
WAYNE NEELY, Bahamas Meteorological Office: The waters are extremely warm.
It's warmer than normal.
And so you have conditions for a perfectly exploding storm.
MILES O'BRIEN: Meteorologist watched Wayne Neely the satellite images with equal parts
disbelief and terror.
WAYNE NEELY: I knew that, beneath that storm, beneath that image, there was going to be
great devastation.
I knew that houses were going to be toppled.
I know that buildings were going to be destroyed.
Life was going to be impacted.
I knew that there was going to be deaths.
It had a pit in my stomach for that.
MILES O'BRIEN: Dorian's 20-foot storm surge killed 67 and obliterated 13,000 homes, the
impact made greater by rising sea levels, which, in November, helped turn high tides
in Venice into the worst flooding in more than 50 years.
And the threat of even greater sea level rise looms, as the West Antarctic ice sheet faces
further assault.
The water captured of the ice here would raise global sea levels by more than 10 feet.
And scientists have concluded Thwaites Glacier, which accounts for two feet of that, is more
precarious than they once thought.
Early in the year, a NASA airborne radar found a 1,000-foot hole at the base of the glacier.
New York University mathematician David Holland is there now, a lead version with the International
Thwaites Glacier Collaboration.
DAVID HOLLAND, International Thwaites Glacier Collaboration: We are trying to head to that
location now to carry out a field campaign to investigate how warm ocean waters are currently
causing it to change elevation and melt very rapidly.
MILES O'BRIEN: Our oceans, which absorb so much of the heat humans are creating, are
changing rapidly.
Temperature-sensitive coral reefs continue their precipitous decline.
We have lost more than one-quarter of them in the last 30 years.
And scientists who study one of the fastest warming bodies of seawater in the world, the
Gulf of Maine, are making a grim forecast for the next 30 years.
ANDREW PERSHING, Gulf of Maine Research Institute: If the planet continues to warm up at an accelerated
rate because we haven't taken care of the carbon problem, that's when Maine starts to
have temperatures that feel more like you would think of New Jersey.
And we don't really think of New Jersey as a lobster state.
As the planet steadily warms, the scientific picture goes steadily clearer.
In may, global dioxide levels surpassed 415 parts per million, an unprecedented high.
In November, scientists gathered in Geneva to deliver a stark warning: Global greenhouse
gas emissions are still on the rise, and for the world to limit temperature rise to 1.5
degrees Celsius, we must reduce annual emissions by 30 billion tons in the next decade.
That is about half of what we emit now.
INGER ANDERSEN, Executive Director, United Nations Environmental Program: We would have
to reduce our emissions.
MILES O'BRIEN: Inger Andersen is executive director of the United Nations Environmental
Program.
INGER ANDERSEN: Now, because of climate procrastination, which we have essentially had during these
10 years, we are looking at a 7.6 percent reduction every year.
Is that possible?
Absolutely.
Will it take political will?
Yes.
Will we need to have the private sector lean in?
Yes.
But the science tells us that we can do this.
MILES O'BRIEN: But geopolitics tells us just the opposite.
DONALD TRUMP, President of the United States: The United States will withdraw in November.
MILES O'BRIEN: The Trump administration began withdrawal from the 2015 Paris agreement,
under which 187 nations pledge to cut greenhouse gas emissions enough to keep global temperatures
from rising no more than two degrees Celsius above pre-industrial levels.
This set the stage for a failed United Nations summit on climate in Madrid.
The U.S., Brazil and Saudi Arabia successfully blocked an agreement on how to implement the
Paris goal.
PATRICIA ESPINOSA, Executive Secretary, United Nations Framework Convention on Climate Change:
Thank you.
Thank you, Madam President.
Good morning to everyone.
MILES O'BRIEN: Patricia Espinosa is executive secretary of the U.N. Framework Convention
on Climate Change.
PATRICIA ESPINOSA: We are not acting quickly enough to enact the detransformation to our
society that will save humanity's future on this planet.
We are out of time.
MILES O'BRIEN: Among those addressing the summit, 16-year-old climate change activist
Greta Thunberg, who this year mobilized a global grassroots campaign to force politicians
to recognize and respond to the realities of climate science.
In September, she sailed on a solar-powered boat to the United Nations General Assembly
in New York City.
That's where she sat down with the "NewsHour"s William Brangham.
GRETA THUNBERG, Climate Activist: We should not underestimate ourselves, because, if -- if
lots of individuals go together, then we can accomplish almost anything.
So, that's what I want people to take out from this.
MILES O'BRIEN: But are enough people ready?
Turning the tide will require some hard choices about how to power our future and pay the
bill.
But it does appear the public is at an inflection point.
This year, Gallup reported two-thirds of Americans believe global warming is caused by pollution
from human activities, rather than natural changes in the environment.
And yet only 44 percent say they worry a great deal about it.
But don't count an intrepid Apollo astronaut among them.
MIKE COLLINS: I feel about the planet today in a different way.
Having gone out 240,000 miles and seeing it gives me a much greater sense of fragility,
a much greater urge to protect that fragility as we go along.
MILES O'BRIEN: In 2019, increasing numbers of Earthlings got the same urge, not because
they saw trouble from afar, but, rather, because it came ever so close to home.
For the "PBS NewsHour," I'm Miles O'Brien on fragile planet Earth.