Articles by Andrew Dessler

Physicists reaffirm that human-induced GHGs affect the atmosphere

It goes something like this:

The American Physical Society, an organization representing nearly 50,000 physicists, has reversed its stance on climate change and is now proclaiming that many of its members disbelieve in human-induced global warming.

Of course that's not true. Today a statement appeared on the APS website saying:

APS Position Remains Unchanged

The American Physical Society reaffirms the following position on climate change, adopted by its governing body, the APS Council, on November 18, 2007:

"Emissions of greenhouse gases from human activities are changing the atmosphere in ways that affect the Earth's climate."

An article at odds with this statement recently appeared in an online newsletter of the APS Forum on Physics and Society, one of 39 units of APS. The header of this newsletter carries the statement that "Opinions expressed are those of the authors alone and do not necessarily reflect the views of the APS or of the Forum." This newsletter is not a journal of the APS and it is not peer reviewed.

For a list of societies that have endorsed the mainstream position on climate change, see this post.

Climate change and the null hypothesis

An excellent post by my colleague John Nielsen-Gammon, the Texas State climatologist, can be found here. An excerpt:

Did I say darndest? I meant stupidest

From Deltoid, Tim Lambert provides this exchange between Tim Flannery (climate realist) and Adam Shand (climate skeptic) from an Australian TV show:

Tim Flannery: No one can predict the weather three months ahead, that's absolutely true. But if I asked you if January next year was likely to be warmer than June this year, what would you say?

Adam Shand: I'd have no idea!

TF: You'd say yes because that's what we always see. Summers are warmer than winter. And in terms of predicting general global trends, that exactly the sort of science that we're doing. It's not like predicting the weather on a certain day three months out, it's like predicting whether January is likely to be warmer than June.

AS: But that's just an assumption, we sort of assume that summer is hotter than winter.

His argument is still bogus

The Washington Post embarrasses itself today by publishing the usual delayer drivel in an op-ed by Bjorn Lomborg.

The fundamental problem with Lomborg's argument (which he also makes in his recent book Cool It!) is that it is based on the assumption that the worst-case, climate-change scenario cannot happen.

The IPCC's predictions for climate change over the next hundred years range from about 2°C to 5°C. If you assume that the warming will be closer to 2° than 5°, which Lomborg does, then it certainly does reduce the pressure to act immediately on climate change. No doubt about that.

However, there is no scientific basis for that assumption. Future warming certainly could be closer to 2°, but it could equally likely be close to 5°. We just don't know.

Why does he make this assumption? Because there is a conclusion he wants to reach: We should not be taking action on climate change. The only way you can reach that conclusion is by assuming that future climate change will be mild.

This argument is bogus. Don't believe it.