Dr. Kate Calvin Interview

Dr. Kate Calvin Interview

Narration:

Transcript:

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I'm Kate Calvin, NASA's

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chief scientist and senior

climate advisor.

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Hi. My name is Doctor Kate Calvin.

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I'm NASA's chief scientist and senior

climate advisor.

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And I'm going to answer

some of the top questions

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that we're getting from users like you

about climate

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Well, what we're seeing over

time is more and more,

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hot years, hot months, hot days,

because of climate change.

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So temperatures are rising overall.

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And with that brings impacts to people

and ecosystems all around the world.

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And while sometimes these numbers may seem

small, our ecosystems and our and

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our people are adapted to the temperatures

that we've experienced in the past.

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And when we have these increasing

temperatures, we're seeing these impacts

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like extreme events,

melting of ice sheets, sea level

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rise, changes in the water cycle

that affect precipitation.

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And we're seeing all of these

impacts all around the world.

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With climate change, we're

seeing more hottest years, hottest months,

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hottest days.

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These are driven by increases

in greenhouse gases

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and they're impacting in these changes

in temperature.

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These extreme heat events are impacting

people and ecosystems all around

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the world.

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We're seeing changes in impacts

like, more extreme events.

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We're seeing declines in Arctic sea

ice, increases in sea level

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changes in the water cycle.

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And these types of impacts are happening

in different parts of the world.

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And they're impacting people,

where they live.

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So with these increases in temperature

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and with climate change,

we're seeing impacts all around the world.

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And those impacts include

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things like declines in Arctic sea

ice, increases in sea level.

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We're seeing changes in extreme

events like heatwaves and wildfires.

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We also see changes in the water cycle

that can lead to more heavy

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precipitation events,

and in some regions, more droughts.

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These numbers look modest on paper,

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One thing that's

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important to keep in mind we often talk

about global average temperature.

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But the temperatures you experience

are different where you live.

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And what we see are more temperature rise

over land and over ocean.

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More at higher

latitudes and lower latitudes.

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And each of these even small changes

can impact, other parts of our Earth

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system in ecosystem like changes

in, in water cycle

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or extreme events

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about this?

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One of NASA's most important

missions is our home planet.

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so we have been studying the Earth

for decades, helping to understand

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how it's changed what it looks like today

and provide that information to people.

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And one of the ways that we study

the planet is through our Earth

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observing satellites.

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So we have more than two dozen

satellites and instruments in orbit

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that are continuously

monitoring our planet.

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And they can show us

things like vegetation, sea level rise,

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carbon dioxide, changes

in the mass of ice sheets, and much more.

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in addition to our satellites,

we also use surface

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and airborne observations to complement

those satellite records.

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And one of the things we do

is we take the surface

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measurements of temperature and construct

a global temperature record.

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And that's how we understand

whether a month is the hottest month

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on record or a year is the hottest year

on record, is by using that surface data

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and constructing this global temperature

record.

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More than 70% of the Earth's

surface is ocean.

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And we're also seeing record warming over

oceans.

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the oceans play a really important role

in our Earth system.

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So they absorb heat and carbon dioxide.

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and some of that heat, you know,

by absorbing it in the ocean,

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it's not in the atmosphere.

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So heat comes in from the sun.

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Some of that heat

is reflected back into space.

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how much is reflected?

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Depends on the color

of the of the Earth's surface.

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It depends on the aerosols

in the atmosphere.

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It depends on clouds.

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Some of that heat,

though, is absorbed by the oceans.

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so the surface of the oceans absorb heat,

and then they mix, taking the heat down

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into the depths of the ocean.

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And then the surface can absorb more.

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But some of that heat

remains in the atmosphere.

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And that's what we're experiencing.

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As increases in temperature

is this heat that's remaining.

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And it's affecting people and ecosystems

and causing impacts all around the world.

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Perfect.

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this.

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El Nino is a natural cycle that affects

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temperatures

and and weather around the world.

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El Nino years

tend to be warmer on average than others.

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La Nina years

tend to be cooler on average.

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But with climate change, what we're seeing

is an overall trend in warming.

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So our La Nina years are also getting

warmer, as well as our El Nino years.

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And so we see an overall trend in warming,

but we're still seeing

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individual years that are warmer

or cooler than the previous year

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because of El Nino and La Nina.

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Yeah.

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So 2022 was a long any year on average.

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La Nina years are cooler than other years.

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But 2022 was the hottest

la Nina year on record.

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2023 was an El Nino year.

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We moved into El Nino,

and as a result, 2023.

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The combination of climate change,

El Nino and other factors mean that 2023

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was the hottest year on record.

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So scientists have been studying

our planet for more than a century,

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and we have different ways

of looking at Earth

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and measuring it and understanding

what's happening.

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So we have observations,

and so we can look at temperature records

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dating back to the late 1800s

and see that temperatures are rising.

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We have observations of carbon dioxide,

a greenhouse gas

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that's driving that warming.

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And we can look at how carbon

dioxide has risen.

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We have laboratory experiments

dating back to the 1850s

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that tell us that carbon

dioxide traps heat and warms temperatures.

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We have models.

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These are computer programs

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that capture our understanding of physics

and how the Earth works.

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And from those models, we can see that

the only way to replicate recent

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warming is to include carbon

dioxide and greenhouse gases.

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And last, we can look at what we what

scientists call fingerprints.

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So these are how exactly, climate change

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is affecting

or or how temperatures are changing.

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And that gives us information

about the drivers.

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So we can look at temperature

in different parts of the atmosphere.

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And what you see

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is that the upper atmosphere is cooling

and the lower atmosphere is warming.

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And that's consistent

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with with, greenhouse gas effect,

where heat is being trapped.

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If we had more incoming sunlight,

you would expect all of the atmosphere

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to warm with greenhouse gases.

You don't have,

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that you have trap the heat at the lower

part of the atmosphere.

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So less is reflected back into space.

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And that's what we're seeing.

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So we can combine

all of these different types

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of information, observations,

laboratory experiments, models,

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and together that tells us both

what is happening and also why.

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So what we do at NASA is we're actually

measuring

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individual temperatures

all around the world.

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And we have different ways

of doing this. One.

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We use the surface temperature record.

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That's the one we often talk about.

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when we're talking about hottest year,

hottest month

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and what that surface temperature record,

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it's a bunch of stations

all around the world

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that are measuring temperature

at the surface of the Earth.

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You might have one,

you could have a temperature,

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in your backyard or at an airport

or in other parts of the world.

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and we measure that at the surface,

and then we can calculate the global

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average temperature from that.

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We at NASA

also measure temperature from space.

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So we have satellites

that can measure temperature.

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And what we see from

those is we actually see the same trends

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that we see

with the surface temperature records.

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So we can confirm those surface

temperature measurements

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by looking at satellite

measurements of temperature.

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But what we're measuring

is local temperature.

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And then calculating an average.

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did we do this human activities

in principle

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through the release of greenhouse

gases are warming our planet.

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So we can look at changes over time

and we can see an increase in greenhouse

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gas emissions

that are trapping heat, in the atmosphere

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and warming our planet.

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Is there hope?

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Well, we know what's

driving the warming on our planet.

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We know it's driven

by increases in greenhouse gases.

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We also know, how to limit warming.

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So we know that by reducing greenhouse

gases and reaching,

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we can reduce the rate of warming.

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And there are options available today

that can help us reduce greenhouse gases.

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There's also people all around the world

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that are working to better understand

our planet, and to develop technologies

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and understanding

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that can help us address the changes

that are happening where I live.

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And there's people like you

that are learning about this now

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and can help us in the future.

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That's

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record?

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Not necessarily.

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So we're

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seeing an overall trend in warming,

but we might still see individual years

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that are hotter

or cooler than the previous,

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and individual months that are hotter

or cooler than the previous month.

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So we are seeing an overall

trend in warming, but that doesn't

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necessarily mean

every single month will be the hottest.

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planets?

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The sun is the source of heat

for our planet and other planets.

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And so we have incoming sunlight.

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Some of that is reflected back into space.

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Some of it is trapped as heat.

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and increase in greenhouse gases

in our atmosphere mean we're

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trapping more heat on Earth, and it's

warming the surface of our planet.

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These are things

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we can measure,

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so we can look over time and see

the change in the incoming sunlight.

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We can see the change in the amount of

heat going back into space and understand

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what's what's happening

and what's driving it, and so on Earth.

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What we've seen

is this increase in greenhouse

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gases, is trapping

more heat and warming our planet.

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We can also look at other planets

and see what's happening there.

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So Venus

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is slightly closer to the sun than Earth,

so it's getting more sunlight coming in.

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But it also has a much, much higher

concentration of carbon dioxide

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in its atmosphere.

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So it's trapping a lot more heat, and it's

hundreds of degrees warmer than Earth.

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at the surface, because of both

the closer to the sunlight,

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but most importantly

because it has a higher concentration

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of greenhouse

gases that are trapping heat.