Narration: Lauren Ward


The reason that we as humans care about climate change

is that it affects not just the temperature,

but a whole bunch of other things that we care about.

It affects soil moisture,

which in turn affects our ability to grow the things that we eat.

It affects cloud cover.

It affects rainfall patterns.

It increases drought risk in some regions and decreases it in other regions.

Understanding our changing climate on a planet with incredibly complex

and interconnected systems is a massive scientific undertaking.

And climate scientists like Kate Marvel are using the data collected

by satellites from around the world to improve the power of climate models.

If we want to make better decisions about

where we live, understand the changing impacts of hurricanes

or improved predictions of fire seasons, we need evolving climate models.

We don't have any observations from the year 2050, from the year 2100,

but we can use our best knowledge of physics and chemistry

and how the Earth system works in order to look at the impact

of different emissions trajectories, different policy scenarios.

Climate models provide a view into our future from our globe

to our own communities.

As models advance, as they're tasked with predicting the nature of the weather

and the clouds over smaller and smaller scales,

they're being asked tougher questions like, Well,

what kind of clouds are happening over those small scales and how often

and how heavily are they raining?

We expect roughly on really, really large scales

climate change is making wet regions wetter and dry regions drier.

But at the same time, it's shifting the circulation of the atmosphere.

So the locations on a very,

very large scale of those wet and dry regions are changing.

Climate models are composed of lots of different calculations on the

different behaviors of our atmosphere, our land and our oceans.

To accurately represent the natural world they need massive amounts

of satellite data over decades from NASA's Earth observation

fleet and its partners around the world.

Satellites like the Global Precipitation Measurement Mission

provide valuable rainfall data

on daily to seasonal timescales for the past 20 years.

And it's that information, along with a suite of other

data that go into climate model development.

Currently, the GPM microwave imager radiance data are used to generate

initial states of NASA climate models and to guide climate model

solutions to be close to real states by applying data assimilation techniques.

Data assimilation is the process of combining many different sources of

Earth observations into models to improve how we represent the Earth system.

Assimilating GPM microwave imager data

improved intensity and locations of storms

and precipitation calculated by the climate models.

And once a climate model is developed, it's tested over and over because, well...

All models are wrong,

but some models are useful, so they're always going to be incomplete.

They're always going to be a not exact representation of the real world.

But we want to make sure that they are capturing important aspects of the Earth

so that we can treat them as credible going forward.

Typically, what happens is when you modify one part of the climate model,

other parts accidentally change.

It's kind of like the Whack-A-Mole game.

By hitting it down, we're improving it, we're killing the error, we're decreasing

the problem existing in a model, but another area pops up.

And that is why NASA observations of the Earth from space, the air and

the ground are critical to understanding how our Earth system works.

Observations help improve the modeling for our future here on Earth,

with new capabilities to expand our knowledge.

NASA is launching satellites and coordinating missions, like GPM,

giving us that long term, really accurate satellite record of what's been going

on, not just the temperature rising, but of various aspects

of the climate changing.

So precipitation and cloud cover and soil moisture,

and a whole bunch of different climate variables that people care about.

Continuing key observations of the Earth is really important

to see how our atmosphere, land and oceans are changing over time.

A long term record, combined with cutting edge observations

from the new NASA Earth System Observatory, will continue

to push boundaries to better understand our ever changing Earth.