Something is going on with the weather.
(lightning strikes)
In the late winter of 2019,
14 U.S. states from North Dakota to Louisiana
are smothered by a historic flood.
A flood that usually happens in spring.
I lost everything, I lost everything.
One month later, a sever winter storm
slams wide areas of the high plains,
spreading deep snow, stranding people and livestock.
A winter storm, in spring.
(alarm sounds)
Then, in April and May,
a severe tornado outbreak in the Central Plains
spins up over 500 twisters,
killing 13 people and flattening towns
from Texas to Iowa.
Extreme weather events just keep coming.
More, bigger, more often.
And the question at the top of everyone's mind,
are these the real impacts of a warming planet?
This is more than an extreme weather story.
This is a story about our food
and our water systems.
This is a story about our health, our economy,
our buildings, our roads.
This is a story about our sports, our tourism,
our ways of life.
And climate change is not this thing
that's going to happen in the future
and we need to just prepare for,
it is happening right here and right now
in communities across the country.
(intense music)
(mysterious music)
There is zero debate
within the scientific community
that the planet is warming.
That's unequivocal, it can't be denied.
The instrumental record gets really good
at about 1950, and it gets even better after that
when we put satellites into space
and we can now make comprehensive measurements
of the glove at a rapid frequency.
And these are all telling us the same thing,
that the planet is warming,
it's warming from the top of the atmosphere
to the bottom of the oceans.
But how do we know all this for sure?
All across the world,
thousands of weather stations record temperature,
rainfall, and wind.
The results of this simple record keeping
are straightforward.
2018 was Earth's fourth warmest year on record,
after 2015, 2016, and 2017.
Nine of the 10 warmest years since 1880
have occurred since 2005.
2019 is on track to be in the top three
warmest years on record.
What's more, the global climate is responding
to all that heat.
Global warming is affecting different kinds of weather
in different ways.
The easiest one for everyone to understand
is that you add more heat,
you're going to have more heat.
Temperatures are higher, heatwaves are lasting longer,
they are more intense,
and we're seeing more of them.
But some other ways that we're seeing our weather change
is the increase in extreme amounts of rainfall,
and this is happening around the globe,
even in places that are drying out.
You have to look at our world as a water world.
So when you take a world that is mainly water,
you evaporate that water into the atmosphere,
there's more of it to actually come down
in these heavy rainfall events,
and that is what we're seeing everywhere.
(dramatic music)
In 1859, Irish scientist John Tyndall
discovered that carbon dioxide, methane,
and water vapor all trap heat in the atmosphere.
40 years later, a Swede, Svante Arrhenius,
predicted that carbon dioxide
from fossil fuel combustion might boost that work,
and coined the term "Greenhouse Effect".
Tyndall and Arrhenius were right,
now the planet is warming,
and for the reasons they discovered.
However, what no one back then could predict
is how atmospheric warming
might change the way weather behaves.
More than that, how it would force a shift
in the global climate,
and change the weather not just for today or tomorrow,
but permanently.
(dramatic music)
You often hear people say,
"So, what's the big deal?
"Climate has changed a lot in the past."
Well, yeah, we know that because
climate scientists had figured out
how climate has changed in the past,
and that's why we're so concerned,
because the changes we're seeing
are far outside of what we would consider
natural variability.
If we compare the future expected changes, right?
We're talking over the next several decades
of a few degrees Celsius, maybe five degrees Fahrenheit.
Changes of that magnitude in the past
have completely reorganized Earth's climate,
so we're talking the difference between
a deep ice age or a very warm greenhouse Earth,
the changes of this magnitude.
And if we continue to put emissions
into the atmosphere,
we expect to exceed the changes that we've seen
in the historic record,
and basically put us back to
climates that were present
when the dinosaurs were roaming the Earth
and there were crocodiles near the North Pole,
and that sort of thing.
So, you know, a couple of degrees Fahrenheit globally
is a massive amount of climate change.
It sounds like an extreme future,
but scientists base it in part on the record
of how the climate has behaved in the past.
Before the mid-19th century,
we could use what we call climate proxies
to try to reconstruct what climate was like.
Things like tree rings,
tree like ocean sediments,
things like ice cores.
From that record, we can rebuild climate patterns
on the order of centuries ago
to millions of years ago,
and those are all telling us that
we're in a period of unprecedented warming
that can't be explained in any other way
except through greenhouse gas emissions.
The growth rings of old trees
report hot and cold, wet and dry periods,
going back hundreds of years.
Ice cores drilled from the bottoms of glaciers
contain bubbles of the atmosphere
as it was hundreds of thousands of years ago.
Ocean sediment cores push the climate record back
even further, to many millions of years.
Forensic analysis of all these so called
paleoclimate models together tells the story
of a climate that has changed naturally through time.
Variations in orbit of the Earth,
sun cycles,
volcanic eruptions,
and other natural forces have all played a part
in changing the climate.
But there is one consistent common theme.
When carbon dioxide levels have been lower,
temperatures have been lower.
When carbon dioxide levels have been higher,
temperatures have been higher.
So going forward, what we can expect
unless we do get a handle
on our emissions that we're putting
into our atmosphere is more extreme weather events.
Including heavy rain, including intense heat,
and intensifying tropical systems.
We're also going to expect rising seas
at an increasing pace,
melting ice from land ice, from glaciers,
and our sea ice not reforming the way it has in the past.
And one thing that people don't always think through
is that these increases aren't going
to happen in a bubble.
These increases are going to happen at the same time.
Different kinds of extreme weather
do seem to be happening all at once, on TV at least.
But people who get hit by big floods, fires,
hurricanes, tornadoes, and heat waves
are not the only people being affected
by warming and the changing climate.
But climate is changing everywhere, all the time.
So, to help people better understand the magnitude
of the changing we're expecting,
we created this future Urban Climate's mapper,
it's a web application that people can go to
and look at any one of about 540 urban areas
in North America to see how climate change
is expected to impact these places.
So people can go to this application,
they can click on an urban area,
and see where the current climate is most similar
to that urban area's future climate.
So, a great example is Washington D.C.
By 2080, Washington D.C. is going to feel like
a town in Northern Mississippi
that's called Greenwood, Mississippi.
So, the typical winter in Greenwood, Mississippi
is about 10 degrees Fahrenheit warmer
than D.C.'s winter is at present,
that's about five, six degrees Celsius,
and it'll be 75% wetter in winter in Washington D.C.
than it is now.
So it's gonna become more sub-tropical, in essence.
Children living in Washington D.C. today,
if they continue to live here,
they're going to live through a dramatic
transformation of climate.
They'll be telling their kids what climate was like,
and their children aren't going to believe
that it used to snow potentially in Washington D.C.
Run the clock forward 60 years,
and all the changes taking place now have added up.
By 2080, weather in Miami will be
more like Southern Mexico.
Minneapolis, Saint Paul, will be more like Nebraska.
St. Louis and Denver will be more like Northern Texas.
The point is, the climate is already moving
in these directions.
Climate change is affecting everyone here and now
just in different ways depending on where you live.
In the west, droughts are getting worse,
that's upping the risk for wildfires,
and that is worsening air quality.
What we're seeing in the middle of the country,
intense heavy rain events,
particularly the Midwest,
where there's a huge uptick
in these heavy rain events
which are wiping out crops for farmers,
and really interfering with the timing of planting crops
and harvesting crops.
Across the south, intense heat is getting more intense
and it's lasting longer.
While extreme weather events increase
in number and strength,
and the growing heat breaks no records yearly,
NASA, NOAA, and national agencies around the world
are keeping a close watch.
NASA has 16 satellites collecting longterm data
on changes in ocean evaporation,
atmospheric water vapor, clouds,
sea and land ice, snow cover,
and other aspects of the global climate.
The growing evidence gives a good picture
of what's happening on the planet.
The world is getting warmer,
and the climate is steadily changing.
The natural world is a really good place to look
for these changes that are going on,
because a lot of aspects of the natural world
are responding, whether it be on land, in freshwater,
or in the oceans,
and so what we're seeing is earlier greening in spring,
early arrival and singing of birds,
earlier first singing of frogs.
We're seeing species shifting their geographic ranges
to the north.
So, species that previously were limited
to southern locations are slowly marching forward.
One of the biggest impacts
from all the warming is on the plant world.
This represents these enormous,
very visible shifts in our climate,
that are changing right in front of our eyes.
This is a USDA map showing the ideal areas
to plant certain crops, and they're color coded.
Now the first image you see is 1990,
I'm going to put it in motion here,
and it'll jump to 2015,
and look at this enormous shift
in the areas where we ideally want to plant crops.
All of that is based on temperatures
and rising temperatures.
In just 25 years, there's been a major shift
in where plants can survive and thrive.
The heat is moving north,
and the plants are moving with it.
The question is, will they be able to adapt
to such a rapid rate of change?
The real problem I think is related
to our ability to grow food,
and extended drought.
And maybe in places like eastern North America
that are predicted to become wetter,
that's not gonna be as big of an impact.
But globally, you know, large scale drought
is going to force people to migrate to new regions,
that's gonna destabilize regions,
and we're gonna have climate migrants,
and I think that's probably
one of the biggest near term impacts.
You know, we focus on natural systems
or things like that, but these impacts to societies
are going to be very large,
and they're gonna ripple across the planet.
(dramatic music)
A record breaking Japanese heatwave in May,
temperatures over 100 degrees Fahrenheit.
Western Australia had its warmest January on record
with temperatures topping 120.
All across South America, heat records fell.
And the Atacama Desert, one of the driest
places on Earth, flooded.
The growing heat, stronger hurricanes,
long droughts, flooding rains,
intense heat waves, rising seas.
Is this really our future?
(dramatic music)
Unless the world can bring down greenhouse
gas levels in the atmosphere,
now at 415 parts per million,
the overwhelming scientific evidence says get ready,
for even more life changing, extreme weather events.
(dramatic violin music)
(thunder cracks)
My goal would be to take our efforts
and expand them globally to do potentially
thousands of urban areas across the planet,
on all of the continents where lots of people live
to try to get everyone across the planet
better informed about why we're concerned.
One of the biggest things people can do
is talk about climate change, and ask questions,
so that they can understand
that their actions have impacts.
And the more you learn about the subject,
the more you're going to understand
how your personal actions are impacting our planet.
(dramatic music)