The initial heavy lifting will have to be done by policy makers. I feel for them. It’s hard to take a tough stand on an important but long-term issue in the face of so many near-term problems, amid worries that reducing emissions will weaken our global economic position and fears that other countries may cheat on their emissions targets.

Where science can help is to keep track of changes in the Earth system — this is a research and monitoring job, led by NASA and the National Oceanic and Atmospheric Administration and their counterparts elsewhere in the world — and use our increasingly powerful computer models to explore possible futures associated with proposed policies. The models will help us decide which approaches are practicable, trading off near-term impacts to the economy against longer-term impacts to the climate.

Ultimately, though, it will be up to the engineers and industrialists of the world to save us. They must come up with the new technologies and the means of implementing them. The technical and organizational challenges of solving the problems of clean energy generation, storage and distribution are enormous, and they must be solved within a few decades with minimum disruption to the global economy. This will likely entail a major switch to nuclear, solar and other renewable power, with an electrification of our transport system to the maximum extent possible. These engineers and industrialists are fully up to the job, given the right incentives and investments. You have only to look at what they achieved during World War II: American technology and production catapulted over what would have taken decades to do under ordinary conditions and presented us with a world in 1945 that was completely different from the late 1930s.

What should the rest of us do? Two things come to mind. First, we should brace for change. It is inevitable. It will appear in changes to the climate and to the way we generate and use energy. Second, we should be prepared to absorb these with appropriate sang-froid. Some will be difficult to deal with, like rising seas, but many others could be positive. New technologies have a way of bettering our lives in ways we cannot anticipate. There is no convincing, demonstrated reason to believe that our evolving future will be worse than our present, assuming careful management of the challenges and risks. History is replete with examples of us humans getting out of tight spots. The winners tended to be realistic, pragmatic and flexible; the losers were often in denial of the threat.

As for me, I’ve no complaints. I’m very grateful for the experiences I’ve had on this planet. As an astronaut I spacewalked 220 miles above the Earth. Floating alongside the International Space Station, I watched hurricanes cartwheel across oceans, the Amazon snake its way to the sea through a brilliant green carpet of forest, and gigantic nighttime thunderstorms flash and flare for hundreds of miles along the Equator. From this God’s-eye-view, I saw how fragile and infinitely precious the Earth is. I’m hopeful for its future.

And so, I’m going to work tomorrow.