The potential is huge, but the transition to the much-ballyhooed hydrogen economy won't be easy. Pure hydrogen isn't a naturally occurring fuel, and today the cheapest way to make it is from oil or natural gas, which does nothing to offset CO2 emissions.

Courtesy Radicalgraphics.org

Lots of people in the media—myself included—are getting really hyped up about global warming these days. All this talk about carbon-dioxide this and fuel-efficiency that. The level of collective anxiety is enough to make me go on a (locally grown, organic) potato-chip binge. Or something. But recently, the cheeky monkeys over at Cosmic Variance advanced a fascinating new theory: that feminism, not greenhouse gas, is destroying the planet. To support their tongue-in-cheek hypothesis, they used a cool new Google tool to build a helpful graph showing tons per capita of CO2 emissions in the atmosphere as a function of the ratio of girls-to-boys attending school in different countries. Where women are educated, they suggest, environmental destruction inevitably follows. Read it and weep. —Megan Miller

Related:It's Pretty Easy Being GreenThe Life Aquatic

An Inconvenient Truth, the documentary on global warming starring Al Gore, opened this week in New York and California. I saw it last night and, though Ive attended several academic conferences related to global warming and its effects this year, this film presents the scientific consensus on the real and significant effects of climate change in the most straightforward and compelling way Ive seen yet.

Of course, there are still some people who dont think theres a problem—for instance, the Competitive Enterprise Institute, a think tank funded in part by the oil industry. Its commissioned a couple 60-second advertising spots that are now airing in 14 U.S. cities and on its Web site. The tagline of the ads: Carbon dioxide: They call it a pollutant. We call it Life. Huh?

Anyway, if youre the type who values science over spin, you might want to calculate your own contribution to the problem at climatecrisis.org (click on Take Action, then Your Impact). There are quite a few of these carbon calculators available on the Web, although this one ups accuracy by adding in your airline miles—which may make some of us holier-than-thou, public-transportation-loving urbanites feel a little less smug.

The hope is that we start thinking about our own CO2 emissions the way we think about our calorie intake (not that we Americans have such a great track record in that area either). You know, like realizing that huge hunk of chocolate cake is a full 600 calories and deciding to split it with your date. Its the same thing for your drive from Boston to Burlington. Ride with someone else, and your impact is half as much.

OK, OK, so carpooling alone wont solve global warming. But getting people to consider their own emissions on a daily basis would be a decent start to building up the political will to take on the problem for real. Need more motivation? Check out these simulated Google maps of the warmer, flooded future.—Kalee Thompson