How NASA Monitors Climate Change from Space

When you look up into the night sky, you may see stars twinkling or the moon shining brightly. But high above Earth, there is an unseen network of satellites that’s always on the lookout. These eyes in the sky are NASA’s, and they are doing something incredibly important: tracking climate change as it happens in real time.

Consider the following: How do scientists know that Arctic ice is melting more rapidly than in other periods? How do they know that sea levels are rising or forests shrinking? They are hundreds of miles above us, in the artificially intelligent satellites that observe Earth daily. NASA uses this data to paint a detailed picture of the ways our planet is changing, which provides us with information we need to understand and respond to climate change.

In this article, we’ll take a look at some of the incredible ways NASA watches our planet from space, the technology they use and why this work is important to all humans on Earth.

Why Space Is the Ideal Place to Watch Earth

You may wonder why NASA bothers sending satellites to space instead of studying climate change from the ground. The fact is, space has certain advantages that are simply unattainable anywhere else.

From orbit, satellites can look down at the entire planet. They don’t have to navigate mountains getting in their line of sight or oceans that are too wide to cross. And a single satellite can scan vast areas in a single flyover, from places where no person could easily go — deep in the Pacific Ocean or the frozen wilds of Antarctica.

Additionally, space offers scientists something called a consistent viewpoint. It’s much easier to see changes when you do so from the same position, which you can if you measure something dozens, hundreds, or even thousands of times from the same spot. NASA’s satellites track the earth on specific paths or orbits, which ensure that they pass over the same spots on the earth regularly. Thus, they can then compare a shot of what an area looked like weeks ago, months ago, or even decades ago.

Also, satellites can “see” things that humans can’t. They have sensors that can pick up signals of light and energy that are invisible to human eyes, from infrared heat to microwave signals. Therefore, they report on the ocean temperature, ice flows, and also changes in carbon dioxide levels which is impossible for them on the ground.

The Architecture of Satellites Focusing on Climate Matters

NASA doesn’t use one satellite to check the change in climate. Instead, they have a fleet of such satellites. They have several satellites which work differently to monitor all the aspects of our environment.

Terra

It uses sensors that measure the clouds, land surface temperature and provides the image and the data of ice that passes in the morning.

Aqua

Uses sensors to measure the particles in the atmosphere, which gives data on forest fires, land surface temperature, and the ocean. It passes in the afternoon.

ICESat-2

It has a sensor that measures the ice by firing a laser at it, and can also detect fires and dust storms over the continent.

GRACE-FO: The Gravity Experts

The Gravity Recovery and Climate Experiment Follow-On mission (GRACE-FO) does something that actually sounds like science fiction — it takes measurements of minute changes in Earth’s gravity. The weight of ice melting and ground water being pumped out of the subsurface can change the distribution of mass on Earth ever so slightly. GRACE-FO detects them, allowing scientists to monitor the movement of water and loss of ice in exquisite detail.

Landsat 9: The Land Observer

Landsat 9 is part of a program that has been operating since 1972 and is the latest in what remains the longest continuous Earth observation program. It captures close-up images of Earth’s land surfaces to see how forests grow, how cities expand, how crops flourish and retreat and how coastlines erode. Landsat data is used by scientists to keep an eye on deforestation, urban expansion and farming practices.

OCO-2: The Carbon Tracker

The Orbiting Carbon Observatory-2 (OCO-2) has a particular target: carbon dioxide. This satellite measures levels of CO2 in the Earth’s atmosphere with extraordinary precision, enabling scientists to track where greenhouse gases come from and where they are absorbed.

What NASA’s Satellites Actually Measure

NASA’s climate satellites gather a vast array of data. Here is a closer look at key measurements that allow scientists to make sense of climate change:

Type of Data	What It Tells Us About	Key Satellites
Ice Sheets	Thickness and where we are losing it at the poles	ICESat-2, CryoSat
Sea Levels	How much water is rising in oceans	Jason-3, Sentinel-6
Ocean Temperature	Heat being absorbed by oceans	MODIS (on Terra/Aqua)
Atmospheric CO₂	Concentrations of greenhouse gases	OCO-2, OCO-3
Forest Cover	Deforestation as well as vegetation health	Landsat, MODIS
Sea Ice Extent	Amounts covering Arctic and Antarctic	SSMIS, AMSR2
Cloud Properties	Effect on Earth’s temperature	CloudSat, CALIPSO
Precipitation	Where it precipitates globally	GPM
Land Temperatures	Heat waves and trends	ECOSTRESS, MODIS

Temperature: Taking Earth’s Fever

Just as a thermometer takes your temperature when you’re sick, NASA’s satellites take the temperature of Earth and its climate system to see how the planet is feeling. Satellites measure temperature differently in different places — some cover the surface of the ocean, others the planet’s land masses and yet others pockets high in the atmosphere.

Monitoring the planet’s temperature is possible because of satellites that circle Earth collecting data nearly continuously for decades, measuring with levels of accuracy that they can finally announce that yes, Earth is getting warmer. The evidence is now clear: Global temperatures have increased by roughly 1.1 degrees Celsius (about 2 degrees Fahrenheit) since the late 1800s, with most of that increase occurring in recent decades.

Ice: Why We’re Watching It Melt

NASA satellites have an interest in ice because it is one of the most visually compelling drivers of climate change. They track three major types of ice — the enormous sheets covering Greenland and Antarctica, the sea ice that floats on polar oceans and the small glaciers that cover mountain ranges.

When it comes to news from space, it’s not good. Data from satellites shows that the Greenland ice sheet is losing about 280 billion tons of ice a year, while Antarctica is losing some 150 billion tons annually. The sea ice in the Arctic has melted at a record pace, and glaciers are also rapidly retreating worldwide.

Sea Level: How We’re Measuring a Rising World’s Oceans

Coastal communities around the world are at increasing risk from rising sea levels. Satellites contain radar altimeters that bounce signals off the ocean to measure its height.

Since 1993, when continuous satellite data became available, the world ocean has been rising at an average rate of about 3.4 millimeters per year (0.13 inches per year). That may not sound like much, but it’s sufficient to intensify flooding in coastal regions, and the rise is speeding up.

Carbon Dioxide: Following the Trail of an Invisible Gas

Carbon dioxide is invisible, but its effects on climate are so enormous you can see it from space. NASA’s OCO-2 satellite measures CO2 levels across the entire globe, producing maps that indicate where emissions are worst and how CO2 shifts through the atmosphere.

Those measurements show that CO2 levels are higher right now than they’ve been at any point in at least 800,000 years, and concentrations have topped 420 parts per million as of 2024. The satellite data also assists scientists in recognizing where on earth natural carbon “sinks” like forests and oceans that take up CO2 are located, and in understanding how effectively they’re functioning.

The Technology Behind the Observations

The instruments on NASA’s climate satellites are marvels of engineering. Let’s take a look at some of the technologies that make these observations feasible.

Laser Altimeters: Precision Ice Measurements

ICESat-2’s laser altimeter is so accurate, it can measure the height of ice sheets to within about two inches (five centimeters) from more than 300 miles up in space. The laser is split into six beams, with 10,000 pulses fired a second. They determine precise elevations by timing how long it takes the laser light to bounce back.

Radar Systems: Seeing Through Clouds

Radar instruments emit radio waves that can pass through clouds, effectively allowing scientists to see Earth even when the weather is bad. These instruments are essential for estimating the thickness of ice, the height of ocean waves and rainfall.

Spectrometers: Reading Light’s Fingerprint

Different gases and substances absorb and reflect light differently. They are detectable in the light emanating from Earth’s surface and atmosphere, and are measured by spectrometers on climate satellites. This allows them to detect specific gases such as CO2 and methane, measure the level of ocean chlorophyll, and assess vegetation health.

Microwave Radiometers: Measuring Heat Energy

They detect the microwave radiation given off by the surface and atmosphere of our planet. The sensors can give information about sea surface temperature, soil moisture, ice concentration and atmospheric water vapor — all pieces in the climate puzzle.

What Satellite Data Tells Us About Climate

Gathering the data is only the beginning. The real work comes when scientists take the information satellites beam back to Earth and process and analyze it.

NASA’s climate satellites beam terabytes of data, that is, thousands of billions of bytes, to ground stations every day. Huge computers then process this raw data, washing out errors that result from everything from atmospheric distortion to satellite positioning wobbles.

Researchers merge information from many satellites to build holistic views of Earth systems. They also put satellite observations in context with ground-based measurements and computer models to build a complete picture of how climate is changing.

The processed data are deposited in huge archives, which researchers around the world can tap into. This open-data policy effectively allows scientists anywhere in the world to make use of NASA’s observations of climate change, regardless of which country produced them.

Real-World Significance: Why It Matters To You

NASA’s space-based observations of the planet help us understand how climate change will slowly evolve, but they are also incredibly useful to inform day-to-day decisions.

Predicting Severe Weather

Satellite data helps meteorologists predict hurricanes, monitor wildfires and forecast floods. When a hurricane develops over the ocean, satellites track its size, strength and direction — helping coastal communities to prepare and evacuate if necessary.

Managing Water Resources

GRACE-FO’s groundwater readings assist farmers, city planners and governments in managing water resources. In drought areas, this knowledge is necessary for making decisions about water use and conservation.

Protecting Coastal Communities

Good sea-level rise data is important for cities facing the coast to be able to plan forward. And they can design better flood defenses, update building codes, and make educated decisions about where to build new infrastructure.

Monitoring Food Production

Data on crops, soil moisture and temperature collected by satellites can predict agricultural yields. This data is useful, in that it helps countries get ready for times of possible food scarcity and it aids farmers to farm the land smarter.

Tracking Wildfires

NASA satellites identify fires as soon as they start and follow their spread in real time. This information helps firefighters assign resources and alert threatened communities.

What Satellites Show About How Earth’s Climate Is Changing

What are NASA’s satellites telling us about climate change today? Here are some of the most important takeaways:

The Arctic is Heating Up Faster Than Any Other Place

Satellite data has revealed that the Arctic is warming about twice as fast as the planet on average. Since 1979, summer sea ice in the Arctic has shrunk by approximately 13% per decade. This sweeping change impacts weather throughout other latitudes as well as at the poles.

Ocean Heat is Breaking Records

The oceans absorb more than 90 percent of the excess heat trapped by greenhouse gases. Measurements from satellites are indicating dramatic increases in ocean heat content, with the warmest years on record in the past decade.

Greenland’s Ice Loss is Accelerating

Data from ICESat-2 and GRACE-FO show that Greenland has been shedding ice more quickly in recent years than it was even a decade or two ago. In some years, it loses more than 500 billion tons of ice — enough to raise sea levels by about 1.4 millimeters worldwide in a year.

Tropical Forests are Shrinking

Landsat satellites reveal persistent deforestation in the tropics, notably in Amazonia and Southeast Asia. These forests are a critical bulwark against CO2, so the loss of them speeds climate change.

What NASA Has To Deal With When Tracking Climate

As advanced as the technology is, NASA still struggles to monitor climate change from space.

Maintaining Continuous Records

The science of climate demands decades of steady measurements to disentangle long-term trends from short-term variations. It is technically very hard, but absolutely necessary, to make certain that new satellites conform to the same measurement standards as their predecessors.

Covering the Entire Planet

Despite dozens of satellites, there are still coverage gaps. The polar orbiters provide what are referred to as “snapshots”—each region of the Earth is observed once or twice every 24 hours and any short-lived events that take less than this will be missed. Clouds get in the way of optical sensors, but radar is a partial solution to that problem.

Processing Enormous Data Volumes

Climate satellites generate so much data, from so many devices, that the processing and sharing of it requires enormous computing power and storage. NASA is always developing new algorithms to handle enormous amounts of data.

Funding and Satellite Lifespan

Satellites don’t last forever. The majority are expected to last 5 to 15 years. It takes a steady stream of funding and long-term planning to make sure that replacements are designed, built and in orbit before the old ones give out.

The Future of Monitoring Climate from Space

NASA continues to find novel and at times critically important ways to observe Earth from above. There are a lot of exciting projects scheduled in the near future.

NISAR: Monitoring Earth’s Surface Changes

The NISAR (NASA-ISRO Synthetic Aperture Radar), a mission in collaboration with the Indian space agency, is preparing for launch in the coming years. It will monitor small changes in the Earth’s surface with greater detail than has ever been possible, tracking movements of ice sheets to land subsidence.

PACE: Ocean Life and Air Quality

The Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission (2024 launch), with the help of state-of-the-art spectrometers is investigating ocean biology and atmospheric particles—as well as their effect on climate.

GeoXO: Next-Generation Weather Satellites

The Geostationary Extended Observations (GeoXO) program will replace existing weather satellites with more advanced models that can monitor air quality, lightning and ocean color in addition to traditional measurements of the atmosphere.

Improved AI and Machine Learning

NASA is in the process of creating artificial intelligence systems that can recognize changes in satellite pictures, see extreme weather events as they form and make climate data available to non-scientists.

How to Get Your Hands on NASA’s Climate Data

The best thing about NASA’s program to monitor Earth’s climate is the data is free for everybody. You can find out what satellites are seeing without being a scientist.

NASA Worldview

This is a free web application allowing you to view satellite images of Earth over the past 20+ years. You can watch ice sheets shift, track wildfires, monitor algae blooms and other climate-related phenomena.

Climate.nasa.gov

This website offers accessible information on climate change, with data visualizations, videos and articles that make sense of what satellites are seeing. Visit NASA’s Climate Change portal to explore interactive tools and the latest findings.

NASA Earth Data

Anyone who wants to delve deeper can use the Earth Data portal on NASA’s website that includes raw satellite data, analysis tools and educational materials for students and researchers.

Working With International Partners

NASA is not the only agency keeping an eye on Earth’s climate. They work with space agencies across the globe: the European Space Agency (ESA), Japan’s JAXA, India’s ISRO and many more.

This international collaboration translates into more eyes in space aimed at Earth, various types of instruments that gather complementary data and scientists from different countries who are working together to understand climate change. The more that agencies like NASA and ESA share data and resources, the better the overall picture is going to be for everybody around the world about how our planet is changing.

The Committee on Earth Observation Satellites (CEOS) coordinates much of this international effort in order to ensure that various agencies’ satellites work together and that the data is shared openly.

Frequently Asked Questions

What is the orbiting time of a NASA climate satellite circling Earth?

Low Earth orbiting NASA climate satellites usually go around once every 90 to 100 minutes. Those in higher, geostationary orbits keep pace with Earth’s rotation and hover over the same point, taking just one complete orbit every 24 hours.

Can satellites forecast climate change or just observe it?

Satellites see what’s happening right now, and they provide historical information on past shifts. This information is then used by scientists in computer models to project how the climate may change in the future. The observations are important for making models accurate, but predictions derive from using data taken from satellites and plugging that information into physics-based climate models.

Why do some climate change skeptics distrust satellite data?

Some misinterpret or misunderstand satellite data — particularly older temperature measurements showing less warming than ground stations. However, those measurement errors were discovered and corrected by scientists years ago. Today, satellites and ground-based measurements agree that warming is occurring.

How accurate are satellite measurements of climate?

NASA’s climate satellites are very accurate. For instance, sea-level measurements are accurate to a few millimeters and temperature measurements are precise to a fraction of a degree. Scientists calibrate satellite data with ground measurements to ensure accuracy.

What happens if a climate satellite fails?

NASA accounts for this with overlapping satellite missions. New satellites are usually launched before the old ones die, so that data records can be maintained. When there are gaps, scientists rely on statistical techniques and data from other satellites to fill in the blanks.

How do satellites measure temperature from space?

Temperature is measured by satellites using this concept: they detect infrared radiation (heat energy) emitted from the clouds and surface. Each wavelength of infrared light represents a different temperature, so satellites can make thermal maps without making physical contact with what they are measuring.

Can anyone contribute to monitoring climate change?

Yes! NASA’s GLOBE Observer app allows anyone to submit observations on clouds, trees, mosquito habitats and land cover. Researchers rely on these citizen science observations to validate and help fill in satellite data.

The Big Picture: Why Monitoring the Climate From Space Is Crucial

Climate change is one of humanity’s most pressing challenges, and you can’t solve a problem if you don’t understand it. NASA satellites bring us the incredibly detailed, high-confidence information that scientists need to understand exactly how and why our climate is changing.

These orbital measurements have hugely reduced uncertainties in climate science. We now know with confidence that Earth is warming, that ice is melting and sea level is rising, and that extreme weather events are becoming more common. We know those things because satellite measurements tell us about them directly, in ways that are difficult to dispute.

But NASA’s monitoring of the climate isn’t just about recording problems — it’s looking for solutions. Satellite data helps governments make smart decisions about what climate policy to pursue, enables communities to prepare for future changes in their backyard and lets scientists test whether our efforts to cut emissions are actually working.

Each piece of information gathered by these satellite-based instruments contributes to our knowledge of how Earth’s climate functions as a system. Hundreds of miles up in space, NASA’s satellites — which are some of the most complex and extraordinary tools we have to make these kinds of observations — monitor our planet like sentinels, transmitting data that help us protect the only home we have for generations to come.

The next time you gaze at the sky, think about the satellites circling above — and think as well of how those devices are measuring climate, showing us what’s happening to this beautiful blue planet. Their observations are a timely reminder that Earth is one interconnected system and what occurs in any one place eventually impacts the rest of us. And in the eyes of these space-based observers, we’re learning to perceive our dear, fragile home as it actually is: a precious and vulnerable place that should be treated with love and respect.