SCIENCE

Climate Change: Why We Worry

December 9, 2009

This figure shows the history of atmospheric carbon dioxide concentrations as directly measured at Mauna Loa, Hawaii. Wikimedia Commons

World leaders and diplomats have gathered in Copenhagen, Denmark this week to figure out what should be the next steps to address climate change. They are convinced that the world is warming in a dangerous way and something needs to be done.

In the United States, though, skepticism is again on the rise, as only 45 percent think that humans are to blame for global warming, according to a CNN/Opinion Research Corporation survey released this week. Another third accept that the world is warming, but they blame natural causes.

I'm not shocked by these results. Every time we write about anthropogenic climate change in the magazine or online, readers write to us saying that we're crazy.

No, we're just very well read, and we've been convinced by the data.

Think we're nuts? That collection of hacked emails from scientists, you say? No evidence of a grand conspiracy or hoax. Just scientists acting like humans (though perhaps sometimes naughty ones).

The world hasn't warmed in the last ten years? You'd be wrong there, too. The World Meteorological Organization said yesterday that 2000 to 2009 was warmer than the 1990s, which were warmer than the decades before.

Perhaps you'd argue that the Earth has survived climate changes in the past, so there's no need to worry now. Yes, the Earth has survived, but a hotter world will put parts of the world under water and make water scarce in other regions, just to start.

We've got higher temperatures and rising ocean acidity, melting glaciers and a disappearing ice cap, birds that have changed the timing of their migrations and farmers that have had to alter their planting schedules, plants that have moved their ranges north and permafrost that has lost its permanency. And, of course, carbon dioxide levels that keep rising to levels never before seen in human times.

This is real, and we are worried.

Even if we lower our carbon emissions and try to stem the tide of climate change, it's going to be bad. Of course, it will be your children and grandchildren that have to deal with the worst of it (and the developing world, even worse than that), so maybe you'll decide that all of this won't harm you and, thus, it's not your problem. Personally, I'd rather argue now about the best way to fix this problem than leave it to my descendants to figure out how to deal with the climate refugees, civil strife and underwater cities.

But if you want to ignore all of the evidence, then go ahead and bury your head in the sand. Try that on a Florida beach in a time of rising sea level, though, and you'll probably drown.