Space offers an unparalleled vantage point for viewing Earth. Only by backing away from our planet can we truly see our tenuous life and how closely related we are. This perspective is critical if we are to understand enough about Earth to make good policy decisions on the ground. I’ve already described the space-based measurements that revolutionized weather prediction. That is just the tip of the Earth system science iceberg (to use an unfortunate analogy). Only from space can we obtain the global data we need to unravel the mysteries of our home planet.

For example, it was satellite data that discovered the ozone hole in the 1980s. Satellite data are currently showing us how fast the Arctic sea ice is melting. We monitor pollution globally to improve air quality around our urban areas. And we are developing better knowledge of how the climate works, thanks to satellite measurements showing how much sunlight penetrates the clouds and hits Earth, and how much heat leaves it. Clouds may hold the clue to how to manage climate change in the coming century.

Clearly, Mission to Planet Earth is more than a science program. It provides the knowledge we need to make decisions, ranging from international policy to national laws, from state and local planning to business strategies. This mission even helps you and me decide how we will live—and what footprint we will leave for future generations.