Warming in the solar system has become a hot topic these days, and I've been getting lots of questions that go something like this: I've read that other planets have global warming. There are no SUVs on other planets, so the warming must be due to increased energy from the sun. Doesn't that mean that Earth's warming is also due to increased solar energy?

The short answer is, whatever warming there may be on other planets is not due to changes in the Sun. Scientists have thoroughly investigated this possibility, and in nearly 30 years of satellite observations, we've seen no increase in overall solar output. (For more on this, see our article on global warming and solar activity [PDF].)

Solar variation cannot explain global warming on any planet, including Earth. So what's up with our neighbors?

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I was in Ohio last week visiting with folks in Cincinnati and Columbus. Most of the discussion focused on business opportunities for Ohio in the new low-carbon economy, but I also got interesting questions about global warming science.

I was especially impressed to learn what the city of Columbus is doing to go "green" (details are on the Columbus city site). We heard from Andy Darrell last week on Mayor Bloomberg's vision for New York City, and it's great to see that New York isn't the only city thinking of a greener future.

But I most wanted to share with you a science question from the visit.

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Lisa Moore is a scientist in the Climate and Air Program.

The EPA just released its most recent estimate of U.S. greenhouse gas emissions, which shows that our global warming pollution continues to climb. Since 1990, emissions are up more than 16 percent. But the EPA is casting this as a victory. How?

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ignoratio elenchi n.
A logical fallacy of presenting an argument that may in itself be valid, but has nothing to do with the proposition it purports to prove. Also known as "irrelevant conclusion". [Lat. ignorance of refutation.]

Richard Lindzen, MIT's most famous (infamous?) science denier, receives our Ignoratio Elenchi award this week for his article "No Such Thing as Perfect Temperature" in Newsweek International. Before critiquing the article's logical fallacies, it's worth noting what Lindzen concedes:

"There has been a net warming of the earth over the last century and a half, and our greenhouse gas emissions are contributing at some level. Both of these statements are almost certainly true."

Even Lindzen no longer questions that greenhouse gas emissions are causing global warming. Now let's examine his other claims.

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Last week, Vic asked about the phenomenon of "global dimming" and its effect on global warming. Good question. Here's the answer.

"Dimming of the sun" or "global dimming" is not due to anything happening to the sun. It's due to something happening on Earth that blocks the sun's rays. Global dimming is important from a climate standpoint because less sunlight reaching the Earth creates a cooling effect.

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Apple blossoms bloom
On too-warm winter days, then
Frost, dead. No apples.

Yesterday was the first day of spring, so it's a good time to look back on the winter we just had. For most of the United States, it was really crazy. It started off with balmy, record-breaking temperatures in December and January, then turned bitter cold in February and March with some memorable and deadly snow storms.

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ignoratio elenchi n.
A logical fallacy of presenting an argument that may in itself be valid, but has nothing to do with the proposition it purports to prove. Also known as "irrelevant conclusion". [Lat. ignorance of refutation.]

The recent NY Times piece on the scientists who have criticized the movie An Inconvenient Truth has generated a flurry of discussion. What I saw when I read it was a series of Ignoratio Elenchi fallacies, so the scientists featured in the article win this week's Ignoratio Elenchi Award.

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In South Pacific
Two islands, encroaching sea,
Life as known is lost.*

In my 30 years as a university professor before coming to Environmental Defense (2 years ago today!), I gave a lot of lectures in a lot of classrooms. But last Thursday I had one of the strangest lecture experiences of my professional life.

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Glaciers in Andes mountains
frozen for 5000 years
now melting.