The first glimpse humanity got of the world from above was transformative. In 1968, the U.S. astronaut William Anders returned from circling the moon in Apollo 8 with a photograph. It was a simple snapshot of the Earth, the whole Earth, rising above the desolate lunar surface. But it was also momentous, representing the very first time anyone had gotten far enough away to view how fragile the world was. The contrast between the lone blue-and-green marble and the cold emptiness of space was beautiful and shocking. As Anders later remarked, “We came all this way to explore the moon, and the most important thing is that we discovered the Earth.”
Anders’s Earthrise photo provided conservationists with the iconic illustration they needed. On April 22, 1970, 20 million people turned out for the largest civic event in U.S. history: Earth Day.
Today conservationists and other critics are more likely to see space programs as militaristic splurges that squander billions of dollars better applied to solving problems on Earth. These well-meaning complaints are misguided, however. Earth’s problems—most urgently, climate change—can be solved only from space. That’s where the tools and data already being used to tackle these issues were forged and where the solutions of the future will be too.
Space research has already been critical in averting one major environmental disaster. It was NASA satellite data that revealed a frightening and growing hole in the ozone layer over the South Pole, galvanizing public concern that, in 1987, produced the Montreal Protocol: the first international agreement addressing a global environmental problem. Since then, thanks to worldwide restrictions on damaging chlorofluorocarbons, the ozone situation has stabilized, and a full planetary recovery is expected. As this case showed, space can provide the vital information needed to understand a problem—and a surprising range of ways to solve it.
Climate change is a poster child for the critical role of space data. Trekking across the globe to measure ice sheets with drills and gauge sea temperatures from the sides of ships is an expensive, slow, and insufficient way to assay the state of the planet. Satellites operated by NASA, the U.S. National Oceanic and Atmospheric Administration, and an increasing number of commercial firms provide a plethora of multispectral imaging and radar measurements of developments such as coral reef degradation, harmful plankton blooms, and polar bears negotiating thinning ice. Much of the technology involved in observing the Earth today was initially developed for probes sent to explore other planets in our solar system.