In 1972, NASA launched a satellite into space that would change how we see the planet -- and the climate. Named "Landsat,” the satellite was initially controversial. To critics, taking photos of the world from space seemed to be a potential national security threat and a waste of money. NASA researchers maintained that it would be useful to see the geomorphology of large swathes of the earth.

Those researchers would be proved right, but not in the way they expected. Landsat has proven to be crucial in seeing how the earth and its climate have changed over the last 50 years. The satellite captured deforestation and glacial melting in its photographs, and also wildfires -- something no other satellite had ever captured so clearly. Landsat’s data was used to create a project called the Global Fire Emission Database, which tracks how much of the globe burns every month and measures the greenhouse gases that result. From this, researchers determined that California’s wildfires "[generate] 25% of the state’s annual emissions from fossil fuels,” and create a seasonal pattern of pollution in North America.

Why This Matters

Satellites are an excellent way to track the effects of climate change. They’ve been particularly useful in measuring atmospheric methane, which is 80 times more warming than carbon over a 20-year period. Some satellites have high enough resolution to detect methane from cow burps over a year. Such precise measurements can help the public understand the scope of the climate crisis, while also holding polluters accountable.

The Value Of Satellite Data

Landsat is unique in that its data is available to the public for free -- nonprofits, researchers from other countries, and even governmental bodies can take advantage of it. The accessibility of Landsat’s data and imagery provided the public with around $3.45 billion in benefits in 2017, according to a report published by the Interior Department and the US Geological Survey.

Despite its benefits, there are always threats to maintaining Landsat’s program. "Incentives to maintain long-term, decade-long archives of data are not necessarily there,” says Jim Irons, Landsat 8’s project scientist. "So while they're taking great data, it may or may not be preserved for future generations.”

But other imaging programs are being phased out. For example, NASA’s Global Ecosystem Dynamics Investigation (GEDI), which maps forests in 3D, is set to end in 2023. Like Landsat, its data has been instrumental in monitoring climate change, proving that more carbon is stored in the Earth’s forests than previously thought, for example. GEDI’s supporters believe the program still has great potential, "It's hard to overstate how important that transparency is,” Douglas Morton of NASA’s Goddard Space Flight Center told Wired. When we are all looking at the same data, we all have the same basis for negotiating the future of our planet. I think when only a few people have that data, it changes the balance of power.”