Speed Kills

On your drive to work today, you probably released around 10 pounds of carbon dioxide into the atmosphere. How long before that starts warming up the planet? A long time, right?

Wrong.

Politicians, policymakers, and even scientists are fond of describing global warming as a problem for our descendants. For example, former U.S secretary of energy and Nobel laureate Steven Chu said that today’s damage won’t be seen for at least 50 years. Others have estimated that CO2 emissions take three to four decades to really start heating things up. But here’s the thing: No one’s ever bothered to check the math until now.

It turns out that carbon traps heat faster—much faster—than we thought. By combining dozens of different atmospheric models, climatologists Katharine Ricke and Ken Caldeira of the Carnegie Institution for Science found that an emission of carbon, regardless of size, reaches its maximum greenhouse effect in just 10 years. (The research actually produced a range from 7 to 31 years, but the overwhelming majority of the results grouped around 10 years.) In other words, you and your car are damaging your own future, not just your grandchildren’s.

You should still worry about your grandkids, though. The study showed that the effects of a carbon emission last a long, long time. Take a look at this graph and despair.

Climatologist Michael Mann’s famous “hockey stick” graph depicts the dramatic rise in global temperatures that began just over a century ago. Well, this is the new hockey stick: It shows that the heat-trapping effects of carbon emissions start early but barely diminish over the course of a century. The data shows that even after remaining in the atmosphere for 100 years, a carbon emission still retains 82 percent of its warming power.

These findings are alarming on a scientific level, but there’s a positive to take from a policy-making perspective.

It’s hard to convince someone to do something—especially something that might cost money—when others will reap the benefits. In fact, sticking future generations with unsolved problems is a grand political tradition: We’ve robbed the Social Security trust fund, ballooned the national debt, and let our infrastructure slowly crumble. Global warming always seemed like another one of those issues for the grandkids. Now we know it isn’t. At least some of the effects of global warming will affect us before we die. That puts climate change communicators in a slightly better position.

Not a perfect position, mind you. Some consequences of climate change, like melting ice sheets and rising sea levels, will still take many decades to be fully realized. And then there’s this: “While the relevant time lags imposed by the climate system are substantially shorter than a human lifetime,” Ricke and Caldeira write, “they are substantially longer than the typical political election cycle.”

Oh, bother.