What NASA Knows from Decades of Earth System Observations

Summary

NASA's Earth science director, Karen St. Germain, discusses how the agency's 23 satellites monitor Earth's systems, revealing a 90 mm sea level rise since the 90s. She highlights the impact of greenhouse gases like carbon dioxide and methane, which trap heat in the oceans, causing melting Arctic ice, coastal flooding, and intensified hurricanes. The script emphasizes the urgency of climate change's effects on agriculture, wildfires, and global water cycles, showcasing NASA's predictive tools to aid decision-makers in addressing these challenges.

Takeaways

• 🛰️ NASA operates 23 satellites dedicated to observing Earth's systems, including the atmosphere, oceans, and land.
• 📈 Sea levels have risen an average of 90 mm since the early 1990s, according to sustained satellite observations.
• 🌱 Carbon dioxide is a critical greenhouse gas, primarily produced by burning fossil fuels, and accumulates in the atmosphere, especially during Northern Hemisphere winter months.
• 🐄 Methane, another potent greenhouse gas, is released from fossil fuel extraction, agriculture, and vegetation decay, but has a shorter atmospheric lifetime compared to carbon dioxide.
• ☀️ Greenhouse gases trap the Sun's energy, leading to increased global surface temperatures over land and ocean.
• 🌊 Approximately 94% of the extra heat trapped by greenhouse gases is absorbed by the oceans, which have a high heat capacity.
• 🧊 Arctic sea ice extent has been decreasing annually, affecting the reflection of the Sun's energy and contributing to global warming.
• 🏔️ Warming oceans erode land ice, such as glaciers, increasing the flow of ice into the oceans and contributing to sea level rise.
• 🏞️ Rising sea levels impact coastal communities and are exacerbated by phenomena like sunny day high-tide flooding.
• 🌱 Changes in the water cycle due to climate change result in wetter regions becoming wetter and drier regions becoming drier.
• 🌀 Intensified tropical storms and hurricanes are fueled by the heat trapped in the warming oceans, leading to more severe weather events.
• 🌾 Climate change affects agriculture by altering precipitation patterns and increasing temperatures, exacerbating drought conditions and impacting crop yields.
• 🔥 Prolonged wildfire seasons and more severe wildfires are observed, which not only damage ecosystems but also release more carbon dioxide into the atmosphere.
• 🌐 NASA's FIRMS tool and partnerships with organizations like the IPCC provide predictive capabilities and tools to inform decisions on climate change impacts globally.

Q & A

What is the primary role of NASA's Earth science directorate?

The primary role of NASA's Earth science directorate is to oversee the agency's efforts in understanding our home planet through the use of satellites that observe the Earth system, including the atmosphere, oceans, and land.

How many satellites does NASA currently have observing the Earth system?

NASA currently has 23 satellites observing the Earth system.

What significant measurement has NASA been able to make since 1993 with its satellites?

Since 1993, NASA has been able to make direct measurements of sea level height, observing an average rise of 90 mm.

What are the two major greenhouse gases discussed in the script, and how do they differ in their impact on the atmosphere?

The two major greenhouse gases discussed are carbon dioxide and methane. Carbon dioxide, produced from the burning of fossil fuels, accumulates in the atmosphere and lasts a very long time, while methane, produced from the extraction of fossil fuels, agriculture, and vegetation decay, is about 20 times more potent but has a much shorter atmospheric lifetime of around a decade.

Why is the trapped heat in the Earth system primarily found in the oceans?

The trapped heat is primarily found in the oceans because water has an enormous heat capacity, meaning it can absorb a lot of heat before its temperature increases significantly.

What impact does the melting of Arctic sea ice have on the reflection of the Sun's energy?

The melting of Arctic sea ice reduces the Earth's ability to reflect the Sun's energy back into space, as ice is a great reflector of sunlight. With less ice, more energy is absorbed, contributing to further warming.

How does the warming ocean affect land ice and contribute to sea level rise?

The warming ocean erodes the underside of glaciers, causing them to thin and eventually break off. This increases the flow of ice from land into the ocean, contributing to sea level rise.

What is the significance of sea level rise for coastal communities?

Sea level rise significantly impacts coastal communities by increasing the frequency and severity of sunny day high-tide flooding and exacerbating the effects of storms and other weather events.

How does climate change affect the water cycle and agricultural yields?

Climate change intensifies the water cycle, leading to wetter regions becoming even wetter and drier regions receiving even less moisture. This, combined with increasing temperatures, exacerbates drought conditions and negatively impacts agricultural yields around the world.

What tool does NASA use to identify and monitor fires around the world?

NASA uses the FIRMS tool, which utilizes high-resolution visible and infrared imagery to identify and monitor fires for decision-makers to understand fire locations and their duration.

How does NASA provide predictive capabilities for climate change impacts to communities and decision-makers?

NASA provides predictive capabilities through tools developed in partnership with the IPCC, allowing communities to locate their position on a map and view projections of sea level rise in their region, both in the present and into the future.

Outlines

00:00

🛰️ NASA's Earth Observations and Greenhouse Gases

Karen St. Germain, NASA's director of Earth science, introduces the agency's extensive satellite network monitoring Earth's systems. She discusses the significant rise in sea levels, traced back to 1993, and attributes it to greenhouse gases. Carbon dioxide, primarily from fossil fuel burning, accumulates in the atmosphere, especially during Northern Hemisphere winters, and has a long lifespan, making it a critical concern. Methane, another potent greenhouse gas from fossil fuel extraction and agriculture, is highlighted for its short atmospheric lifespan. The trapped heat from these gases, especially absorbed by the oceans, leads to various environmental impacts, including Arctic sea ice melting and its consequences on albedo effect and global temperatures.

05:07

🌊 Impacts of Climate Change on Sea Levels, Coastlines, and Agriculture

The script delves into the effects of warming oceans on land ice, leading to increased glacier melting and subsequent sea level rise, which contributes to high-tide flooding in coastal communities. The importance of understanding sea level rise is underscored by its impact on water cycles, making wet regions wetter and dry regions drier. This shift affects agriculture, with changing precipitation patterns and increasing temperatures exacerbating drought conditions. The script also discusses the intensification of tropical storms and hurricanes due to warmer ocean temperatures, which serve as fuel for these weather phenomena. Future projections for maize and wheat production illustrate the significant economic and agricultural implications of climate change, with altered crop yields and growing regions.

10:12

🔥 Wildfires, Predictive Modeling, and Tools for Climate Decision-Making

The final paragraph addresses the changing patterns of wildfires, including extended seasons and more severe events, which not only damage ecosystems but also contribute to atmospheric carbon dioxide levels and air quality issues. The discussion then shifts to NASA's use of satellite data for predictive modeling, emphasizing the FIRMS tool for identifying and monitoring fires globally. A partnership with the IPCC is highlighted for creating accessible climate change projections, allowing communities to assess their vulnerability to sea level rise. The summary concludes with a call to action, emphasizing the urgency of NASA's work in providing accurate observations and models to inform climate-related decisions at all levels of governance.

Keywords

💡NASA

The National Aeronautics and Space Administration (NASA) is the United States government agency responsible for the nation's civilian space program as well as for aeronautics and aerospace research. In the video, NASA is highlighted for its role in Earth science, specifically through the use of satellites to observe and understand our planet's systems, emphasizing its broader mission beyond human and planetary exploration.

💡Earth System

The Earth System refers to the complex, interacting physical, chemical, and biological processes that make up the Earth, including its atmosphere, oceans, and land. The video script discusses how NASA observes the entire Earth system to gain insights into our home planet, highlighting the comprehensive nature of their research.

💡Sea Level Rise

Sea level rise is the increase in the volume of water in the world's oceans, which causes a corresponding rise in sea levels. The script mentions that sea levels have risen on average 90 mm since the early 1990s, which is a key indicator of climate change and has significant implications for coastal communities and ecosystems.

💡Greenhouse Gases

Greenhouse gases are gases in the Earth's atmosphere that trap heat, contributing to the greenhouse effect and global warming. The video discusses two primary greenhouse gases, carbon dioxide and methane, and their respective roles in climate change, including their sources and atmospheric lifetimes.

💡Carbon Dioxide

Carbon dioxide (CO2) is a greenhouse gas that is released through various natural processes, such as respiration, and human activities, such as deforestation and burning fossil fuels. The video emphasizes the long-term accumulation of CO2 in the atmosphere and its critical role in climate change.

💡Methane

Methane (CH4) is another potent greenhouse gas, approximately 20 times more effective at trapping heat than carbon dioxide. The script explains that methane is produced from the extraction of fossil fuels, agriculture, and vegetation decay, and while it is less long-lived in the atmosphere, its impact on climate change is significant.

💡Heat Capacity

Heat capacity is a measure of the amount of heat energy required to raise the temperature of a substance by a certain amount. The video uses the concept of water's heat capacity to explain why oceans absorb a large portion of the excess heat trapped by greenhouse gases, leading to only a gradual increase in ocean temperatures.

💡Arctic Sea Ice

Arctic sea ice refers to the frozen ocean at the Earth's northernmost region. The script discusses the shrinking extent of Arctic sea ice over the summer months, which is a visible sign of climate change and has implications for albedo and global temperature regulation.

💡Land Ice

Land ice includes glaciers and ice sheets that form on land and flow into the oceans. The video describes how warming oceans can erode the underside of glaciers, leading to an acceleration of ice flow into the sea and contributing to sea level rise.

💡Coastal Communities

Coastal communities are areas near the shoreline that are particularly vulnerable to the effects of sea level rise, such as flooding and erosion. The script highlights the projected increase in sunny day high-tide flooding as a direct consequence of rising sea levels, affecting these communities.

💡Water Cycle

The water cycle, also known as the hydrologic cycle, is the continuous movement of water on, above, and below the surface of the Earth. The video script explains how climate change is intensifying the water cycle, leading to wetter conditions in wet regions and drier conditions in dry regions, with implications for agriculture and freshwater availability.

💡Tropical Storms

Tropical storms are large, organized weather systems with closed, low-pressure circulations that form over tropical or subtropical waters. The script mentions that the warming oceans are fueling more intense tropical storms and hurricanes, which can lead to severe weather events and flooding when they make landfall.

💡Agriculture

Agriculture refers to the practice of cultivating plants and livestock for food, fiber, and other products. The video discusses how climate change, through changing precipitation patterns and increasing temperatures, is impacting agriculture yields, affecting both food production and the broader economy.

💡Wildfires

Wildfires are uncontrolled fires in wildland areas, which can be caused by natural events or human activities. The script describes the changing patterns of wildfires due to climate change, including extended wildfire seasons and more severe fires, which have ecological and atmospheric implications.

💡Climate Modeling

Climate modeling involves the use of computer simulations to study the climate system and project future climate conditions based on various scenarios. The video mentions the importance of climate models in understanding and predicting the impacts of climate change, such as sea level rise and changes in agricultural productivity.

💡FIRMS Tool

The Fire Information for Resource Management System (FIRMS) is a tool developed by NASA that uses satellite imagery to identify and monitor fires around the world. The script highlights FIRMS as an example of how NASA's technology aids decision-makers in understanding and responding to wildfire events.

💡IPCC

The Intergovernmental Panel on Climate Change (IPCC) is an international body that assesses the science related to climate change. The video script mentions a partnership between NASA and the IPCC to create tools that make the projections from IPCC reports accessible and understandable for communities around the world.

Highlights

NASA operates 23 satellites to monitor the Earth system, including the atmosphere, oceans, and land.

Sea level has risen an average of 90 mm since the early 1990s, as observed by NASA satellites.

Carbon dioxide is a critical greenhouse gas, primarily emitted from burning fossil fuels and accumulates in the atmosphere, especially during Northern Hemisphere winter months.

Methane, another potent greenhouse gas, is produced from fossil fuel extraction, agriculture, and vegetation decay, with a shorter atmospheric lifetime compared to carbon dioxide.

Greenhouse gases trap the Sun's energy, leading to a rise in global surface temperatures over land and ocean.

Approximately 94% of the extra heat trapped by greenhouse gases is absorbed by the oceans.

The Arctic sea ice extent has been decreasing annually, impacting the Earth's albedo and climate feedback loops.

Warming oceans contribute to the melting of land ice, increasing sea level rise through glacier thinning and calving.

Antarctica and Greenland's ice sheets are major contributors to global sea level rise, with direct mass measurements indicating significant land-to-ocean ice loss.

Rising sea levels threaten coastal communities with increased sunny day high-tide flooding.

Climate change intensifies the water cycle, causing wet regions to get wetter and dry regions to get drier.

Warmer oceans fuel more intense and rapidly developing tropical storms and hurricanes.

Climate change impacts agriculture through increased drought conditions and changing precipitation patterns.

Future projections show a shift in crop production, with implications for food security and the economy.

Increasing drought and changing wildfire patterns lead to extended wildfire seasons and more severe fires.

NASA's FIRMS tool uses high-resolution imagery to identify and monitor fires worldwide for decision-making purposes.

A partnership tool between NASA and the IPCC allows communities to visualize and project local and future sea level rise impacts.

NASA's continuous observations and models provide predictive capabilities to inform decisions on climate change mitigation and adaptation.

Transcripts

Hi, I’m Karen St. Germain, and I am NASA's director of Earth science.

Often when people think of NASA, they think of human exploration or planetary exploration.

They might not know that NASA has 23 satellites looking down at our Earth system to help us understand our home planet.

We've been observing the Earth for decades, and we observe the atmosphere, the oceans, the land - the entire Earth system!

I'm going to talk to you today about what we know from those observations.

This is an example of the kind of sustained observation that NASA satellites make.

Starting in 1993 until just our recent launch of the Sentinel 6 Michael Freilick satellite, we've been observing directly measurements of sea level height, and from those data we know the sea level has risen on average 90 mm just since the early 90s.

But what's causing the sea level rise?

We all have heard about greenhouse gases, and I'm going to talk to you today about two of them.

The first one is carbon dioxide.

Of course, carbon dioxide permeates our atmosphere. By just adjusting the color so I can emphasize the maximum areas of emission,

I can show you where carbon dioxide and when carbon dioxide is being emitted into our atmosphere.

Carbon dioxide accumulates most during the Northern Hemisphere winter months.

Carbon dioxide is created by the burning of fossil fuels, and that carbon dioxide accumulates in our atmosphere over the course of the winter.

And it's only in the spring with the emergence of vegetation that it starts being removed from the atmosphere.

Carbon dioxide left in the atmosphere lasts for a very long time, and that's why there's so much conversation with carbon dioxide as one of the critical greenhouse gases.

But on the next slide, I'll show you the other big greenhouse gas, methane.

So while carbon dioxide is produced from the burning of fossil fuels, methane is produced from the extraction of fossil fuels and also from agriculture and vegetation decay.

Methane is about 20 times more potent a greenhouse gas than carbon dioxide,

but the good news is its lifetime in the atmosphere is much shorter: It lasts only around a decade.

So when we talk about mitigation types of decisions, it really matters to understand where the greenhouse gases are coming from

and how they play in the atmosphere.

What do greenhouse gases do?

Well, they trap a lot of the Sun's energy in the Earth system, and that is raising surface temperatures around the world over both land and ocean.

We can estimate the total extra heat trapped in the Earth system since we started making satellite observations around the year 2000.

Where does all that heat go?

Well, it turns out that today about 94% of it gets trapped in our oceans.

Water has an enormous heat capacity.

That means it absorbs a lot of heat before its temperature goes up, and you know this if you've ever put a pot of water on the stove to boil.

But that heat doesn't stay put.

Our oceans are incredibly dynamic, with currents and eddies that carry that energy around the world and impact coastlines and in coastal communities weather patterns and more.

I'll just talk to you about a few of the impacts from the heat trapped in our oceans.

One of those impacts is in the Arctic.

You're looking down at Arctic sea ice. This is data from just this year showing you the extent of the Arctic sea ice. This is frozen ocean.

Well, over the course in the summer, of course that sea ice starts to melt, and that extent shrinks.

We've been looking at Arctic sea ice for decades now.

We know that every year at the end of the summer there's less and less ice.

Why does that matter?

Well, ice is white!

It's one of the great reflectors of the Sun's energy, so in the summer months, when the Sun is beating down on the Northern Hemisphere, the less ice we have, the less power we have to reflect the Sun's energy back out into space.

And this year, the summer minimum extent was substantially less than it has been in recent decades.

Another way that the warming oceans affect the coastline is through the impact on land ice.

So land Ice flows through glaciers to the oceans, and at that boundary, that warm ocean can erode the underside of the glacier, causing it to thin and eventually break off, and that is like a cork getting popped out of a bottle!

It increases the flow of ice from land out into the oceans, and we know how much of that is happening.

Next slide, please.

The two biggest ice sheets are Antarctica and Greenland.

We know where that ice is flowing from land out into the ocean, and that these two ice sheets alone contribute one-third of the total sea level rise that we observe.

We know that in part because we make direct measurements of the mass of the ice on these ice sheets, so we know how much mass has been lost from land transported into the oceans.

So why do we care about sea level rise?

Well, one of the reasons is our coastal communities.

We project a dramatic increase in just sunny day high-tide flooding, when high tides ride on top of that sea level rise.

But there's more.

Next slide, please.

Our Earth is a water planet.

And you might ask, “If I live inland, why does this matter to me?”

All of the water that we need to sustain life inland, to grow crops, to drink —

all of that water comes from the ocean, and it's delivered to us by the atmosphere.

That's the water cycle.

One of the things that we're seeing with climate change is an increase in the magnitude of that water cycle.

Wet regions get wetter.

Dry regions get drier.

Next slide.

One of the ways that wet regions get wetter is through the intensity of tropical storms and hurricanes.

We all know that when tropical storms pass over warm water, they intensify.

Well, all of that heat that's getting trapped in the oceans and warming the oceans, that's fuel for hurricanes.

We are seeing more and more hurricanes intensify, sometimes intensify very rapidly.

Then, of course, when they make landfall, depositing all of that moisture over land.

Sometimes stalling for long periods of time, causing extended flooding.

We also see flooding inland, along our rivers in our watershed areas.

Of course, inland along the waterways is often where we have agriculture regions, and that's impacting the agriculture yields there as well.

Speaking of agriculture, there are two ways that climate change can impact agriculture.

One we just talked about: wet regions getting wetter.

But the other extreme is also impacting agriculture.

That is drier areas receiving even less moisture!

When the temperatures go up, the demand that plants have for water also increases.

This combination of increasing temperatures and changing precipitation patterns is exacerbating drought conditions and adverse impacts on agriculture around the world.

Next slide, please.

We can project this out into the future. I'm showing you here future projections of maize, or corn production, as well as wheat production.

Red areas will have lower yield, and green areas will have higher yield.

You are seeing a dramatic shift in where and what crops can be grown.

One of the reasons that this is important to us is we might think of maize or corn as food for us or in food for animals, but also, maize is used in many, many household products, from wallpaper to adhesives to batteries.

When we talk about a major change in the ability to produce maize, we're really talking about substantial economic change.

Next slide, please.

With increasing drought and dry spells around the world, we are also seeing a change in the patterns of wildfires.

We are seeing extended wildfire seasons, with less time for recovery in between wildfire seasons.

We're seeing more severe wildfires and more rapid growth of wildfires.

This matters not only because the fire damages the immediate area, but it also increases the carbon dioxide in the atmosphere.

It has an adverse impact on the air quality in the region, in addition to making the region vulnerable to cascading effects like landslides when the rains do come.

Next slide, please.

So I talked you through some of what we can see from our satellite and some of what we understand from our satellites.

Now, I want to talk about how we modeled those changes to give us predictive capability.

Now, I’d like to take just the last couple minutes to talk to you about how we try to bring that predictive capability to people who have decisions to make.

One of the tools we use, or we developed, is called the FIRMS tool.

This is a tool that uses our highest resolution visible and infrared imagery to identify fires around the world, whether they are intentionally set for clearing fields or other purposes or wildfires that are threatening local communities.

This tool allows decision-makers to understand where those fires are happening and how long they have been burning.

Finally, the last tool I’d like to show you is one we're really proud of.

It was a partnership between NASA and the IPCC to make the projections from the recent IPCC assessment report real to people.

Communities around the world can use this tool by just locating their position on the map.

They can zoom in and find out what we know about sea level rise so far in their region, and also project out into the future so they know what they may be facing.

In summary, let me end where I started.

NASA satellites are looking down at the Earth all the time — the atmosphere, the land, the ice, the oceans.

We capture those observations in understanding, and we capture that understanding in models. Those models let us predict.

We know that our climate is changing! We are at about 1.2 degrees so far.

We are still learning how the whole system works, but we do know that there's an enormous range between the best and the worst outcomes.

We are working with urgency to bring you the best observations, models, and predictive tools we can to help inform decisions locally, nationally, and internationally.

Thank you.