In part, it depends on who you are willing to believe: the international community of climate scientists who may all secretly be socialists out to destroy the capitalist system… or a bunch of totally objective oil company employees who would never put their profit ahead of the good of humanity.
Okay, that may not be the most dispassionate and objective way to lay out the facts. Let’s try doing this like scientists: put all the data on the table, and let you, the reader, decide.
What do the scientists say?
In January of 2009, the University of Illinois released a study of 3,146 scientists, all members of the American Geological Institute’s Directory of Geoscience Departments. Here’s what they found:
Ninety percent agreed that global temperatures have been rising since the 1800s. And 82 % agreed that human activity had been a significant factor.
An even stronger statistic though: among those who know the most about climate – the actual climate scientists – there was 97 % agreement that humans play a role.
The biggest doubters were petroleum geologists (no surprise there), and meteorologists, the guys who study minute daily fluctuations – weather – but aren’t involved in big-picture research – climate.
What is climate?
Climate is the flow system that moves energy around on the earth’s surface and atmosphere. The energy comes from sunlight, and it hits half of the Earth at a time. Half the Earth is always warmer, half the earth is always cooler, and energy flows from the hotter places to the cooler ones. We have seasons as well as a day-night cycle, so that makes things even more complicated. And of course, the sun hits more directly near the equator, and more indirectly at the poles, so add that to the mix, too.
The climate in any one particular place – say, Las Vegas – is extremely variable. In general it’ll be hotter in summer and milder in winter, but because of the chaotic way energy gets shunted around, you can get cold snaps in June and mild, Indian-summer weather in November. You don’t usually get snow in Vegas in the winter – but it shouldn’t surprise you too much if every so often it comes down in a blizzard.
The Earth itself, though, is a much bigger system. When you’re talking about climate, it makes no sense to ask about whether it’s snowing in Las Vegas, or whether Topeka got a cold snap in June. You have to look at the entire global system.
And for the entire global system, 2008 was the 8th hottest on record. And all 10 of the Top Ten Hottest Years have happened since 1997. The leader: 1998 (which has caused some climate skeptics to claim that “Looking at the past ten years, the temperature trend is actually down.” )
-> Next page: How Scientists Work
More on Climate Change and Global Warming from Red Green and Blue:
- Is Sea Level Rise Really a Big Deal?
- Yes, Cold Weather in Europe STILL Means Global Warming
- Fox News Viewers Misinformed About Global Warming
- Bill McKibben at Powershift: It’s up to YOU to act
- GOP Votes to Repeal Climate Science
- Video: What impact will climate change have on the oceans?