科学美国人60秒:Climate Change Getting Worse by the Minute

What goes up and doesn't come down? Greenhouse gas emissions, apparently. The world set another record in 2012, spewing some 31.6 billion metric tons of carbon dioxide, methane, hydrofluorocarbons and other greenhouse gases into the air.

The 2012 contribution keeps us on pace for not one more degree Celsius of warming, or even two, as is the avowed goal of the international climate negotiations that saw another inconclusive round conclude this past week. We are on track for 3 degrees C of warming or more, this century.

That calculation comes from the International Energy Agency, a kind of cartel for oil-consuming rich nations. But don't despair. The U.S. in recent years has reduced its greenhouse gas emissions back to levels last seen in the 1990s. That's thanks mostly to burning less coal.

And there are some quick and easy steps that could reduce emissions globally: more energy efficiency, less leaking methane, an end to fossil fuel subsidies and a ban on inefficient coal-fired power plants. If we did all of those, we might get on a new track that leads to a world that’s less hot and bothered.

—David Biello