How did you become a climate scientist?

I got my Ph.D. in theoretical physics from Cambridge. Then I got kind of frustrated with the field that I was in while I was in graduate school and I wanted to do something more applied. I wanted to do something that was more relevant to people’s lives and would make more of a difference. And I got a postdoc fellowship at Stanford, where they let me work on whatever I wanted as long as it had a science component and a policy component. I dabbled in a couple things and then I found climate science and I haven’t looked back since.

What was it that captured your attention?

I love that everything on the planet is connected. I love that things are both predictable and very complex. I say I went to grad school to study the whole universe and then I realized that this is the best place in the entire universe. Things like the fact that the rising air from the tropics sinks and when it sinks that’s where it creates the great deserts of the world. So we wouldn’t have deserts if it weren’t for the tropics. I think that’s beautiful.

Your TED Talk focused on the role of clouds in climate change. What are you researching right now?

My research goes in two directions. One is this question of what does climate change look like and is it happening. That means how is climate change affecting the variables that we care about. Not just temperature, but things like rainfall, globally and locally, things like cloud cover. So a lot of my research is focused on understanding the changes that we are experiencing and putting them in context.

I’m also interested in something called climate sensitivity, which is basically: How hot is it going to get? The number one reason we don’t know how hot it’s going to get is we don’t know what we’re going to do. We don’t know what emissions are going to look like. Even if we were to remove that uncertainty, we still couldn’t say with 100 percent confidence how hot it was going to get. That’s because there is a lot we don’t understand about a changing climate.