Climate Change: It's the Physics, Stupid

What are the politics of physics? This is the question I posed to a family member this weekend. We were discussing the reality of climate change. If you’ve been following me for the past year, you know where I stand. Unfortunately, a couple of my family members along with a good chunk of Americans don’t get it.

So in honor of my family, I’d like to indulge in a quick physics lesson. Because at its root, climate change is a physics problem. At its root, it’s this simple concept: energy in equals energy out.

I’m writing this while sitting in the Detroit airport. So in honor of my current location, let’s talk cars for a minute. How does a car get you from point A to B? The combustion of gasoline. There’s stored energy in gas. Through the process of combustion, you transfer that energy into the gears and belts that turn your motor, sending you on your way to the grocery store.

Still with me? Good!

Now let’s talk about a bigger system: the planet. Energy in equals energy out. The outside energy in this case comes from the sun. You’re probably familiar with that energy if you’ve worn a black shirt on a sunny day.

Ultraviolet radiation happens to have a similar relationship to our planet. The Earth absorbs some of that radiation. It then radiates it back into space as infrared radiation.

Along the way back to space, greenhouse gases in the atmosphere trap some of that outgoing radiation. They in turn radiate that energy in all directions, some of it coming back towards the Earth.

Without greenhouse gases our planet would be uninhabitable. The surface temperature of the Earth would be around -19 degrees Celsius without any greenhouse gases in the atmosphere.

With them our planet is habitable. With too many, our climate system starts to change. And we’ve been emitting quite a few since the Industrial Revolution so that atmospheric concentrations are higher than they’ve been at any point in the last 800,000 years.

So why does this matter? More greenhouse gases means more energy stays in the Earth’s system. And that means the surface temperature of the Earth increases.

Just like you go faster in your car if you push harder on the gas pedal. Just like you get warmer when you put on a coat. Simple physics.

Was this all painfully obvious? I hope so. But for some reason the logic seems to escape almost half of conservative elected officials in the US as well as over a quarter of the general population. Would you be so kind as to share this with them?

We can debate the accuracy of models. We can debate the exact effects of climate change. Those are areas where the science is still quite active. And we can certainly debate what the best policy paths forward are. That’s politics.

But please, can we agree, physics has no politics.

Photo creditL thinlysliced/Flickr