why is global warming so cold?

Just because it's cold outside in your part of the world doesn't mean global warming isn't happening.

It's cold where I am. Really cold. It's been really cold for the last two weeks and it'll be really cold for at least another week. Then again, it's the middle of winter and I can't say that I'm surprised that it's cold at this time of the year. It's kind of expected when you think about it. But don't tell that to the anti-global warming crowd which is using this bitterly cold January to make snarky jokes about Al Gore and write editorials in which they say that there's no way a planet can be heating up when we're in the middle of a cold snap.

As shocking as it might sound, even in a warmer world it will still be cold and there will still be freezing rains, icy temperatures and bitter cold snaps. When scientists talk about a warming trend, they're talking about a maximum warming of five or six degrees averaged for the entire planet. The middle of winter will still be cold and snowy, it's just that the places where it will be cold will be farther north than they are today.

Don't get me wrong though. Five or six degrees up or down for the entire planet is the difference between an ice age and a hothouse. In the last Ice Age it was just five degrees colder than it is today. And yes, there were warm, humid places during the ice ages, it's just that the polar ice sheets grew to cover much more area than they do today and winters in the north lasted longer.

Global warming doesn't mean that temperatures won't go down by more than a few degrees as the forests around you burn to a cinder and your backyard turns into a barren desert. Likewise, a cold snap doesn't disprove averages compiled over decades. We can't accurately predict the weather because weather is chaotic and measured by hours and days. It's like a coin flip. Heads or tails. But climate is an average of hundreds of these coin flips and we know that over time, if we toss enough coins, we'll have a similar number of heads to tails.

Climate modeling just ups the temperature ranges we measured over many decades and tries to see what happens to our planet when the average temperature across the globe is higher or lower than it is today. If you want to disprove our grip on climate, show some data for winters with average temperatures of 30 degrees randomly interchanging with 70 degree winters without a special cause behind it.

Finally, there's the Al Gore thing. I've written before how Gore did a disservice to climatologists by injecting partisan bickering into what should've been a purely scientific debate. Really, this issue isn't about a person who embraced global warming as a cause to stay in the limelight. It's about the science and trying to stay objective. With the amount of vitriol many critics direct at the former vice-president, I can't help but wonder if the same crowd would be lambasting him for missing the "threat to our planet" were he a global warming denier instead…

update 01.06.2010: As odd as it may seem, it's cold in the winter of 2010 too, and due to a peak in this post's traffic, I thought it would be beneficial to revisit the topic of weather vs. climate and cover more information on the politics and science of global warming in a follow up entry.