Mike Mann and Lee Kump weigh in with "Dire Predictions"

Summer Reading? No, actually, Required Reading

I don't know how I missed Michael Mann and Lee Kump's new book Dire Predictions: Understanding Global Warming in the previous summer reading wrap.

Some of the most prominent deniers in the game have made themselves famous criticizing Michael Mann's work. But here's the deal: Michael Mann DOES the work. He's not a journalist or politician (Christ Monckton); he's not an Philip Morris and Exxon Mobil consultant (Fred Singer); he's not a stock promoter and amateur statistician (Steve McIntyre). He is an Associate Professor in the Department of Meteorology and Geosciences at Pennsylvania State University and the rarest thing in the very public debate about climate change: someone who knows what he's talking about.

Co-author Lee Kump is also a geoscientist at Penn State and between them they have crafted an accessible primer on climate change, how it's happening and who's to blame.

Here's the reaction from some people we trust. 

With its eye-grabbing graphics and reader-friendly prose, Dire Predictions walks us through the findings of the world's leading climate scientists - and places the ultimately responsibility for the human future directly at our feet.
- Ross Gelbspan

Here's a powerful, straight-forward guide to how scientists, economists, and engineers really understand the problem of global warming. It makes 20 years of research and consensus-building completely accessible to anyone who cares to know the truth–and to do something about it.
- Bill McKibben

Dire Predictions is a must read for anyone who wants the straight facts on global warming. It cuts to the heart of the massive 2007 IPCC report, presenting major scientific findings in easy to understand language and graphics. Written by two of the scientific community's most thoughtful researchers, Dire Predictions' unbiased message about global warming arrives at a time when people need it most!
Dr. Heidi Cullen, Climate Expert at The Weather Channel


For those who would like to see some interesting graphics from a public talk by Mann, see


The mention of amateur statistical complaints brings up an interesting point. If you read Climate Audit, you will often see quibbling based on misunderstanding of statistical methods, sometimes at a fairly elementary level. For example, here is a detailed review of a talk by Mann, and a report of a conversation with Mann. Red flags regarding confusion over statistics by the skeptic appear here and there,


1) Quote: I was a bit surprised by this last comment and said to him “From my understanding of statistics, isn’t r2 as a measure of correlation important when determining the validity of a regression model?”.

No, it isn’ta measure of correlation, as any student of even a basic statistics class should be able to tell you. It may look like a measure of correlation, to the uninitiated, because it has an “r” in it. In any case, it is just one descriptor of explanatory value, and whether or not it was used in support of the conclusions is not relevant.

2) Quote: “I asked him if he would put to rest for me my concerns about his calculations of r2 in MBH98, not providing the results of these calculations, and whether or not the r2 results were significant.”

Well, r2 is never statistically significant, since it is not a test statistic or part of a hypothesis test (actually, it is usually called R2, in the case that the speaker is talking about, but no matter). I hope the speaker doesn’t mean statistically significant; maybe he is speaking loosely and accidentally chose a word that has a certain meaning in statistics. Anyway, at this point and many others in the Climate Audit quibbling, I stop reading, because the points themselves are not “significant” and didn’t make it to “interesting”. It is like arguing against any statement about anything, because no dataset is ever perfect, or because no analysis every completely fits the perfect situation.

&c., &c., &c.

When you spend the great majority of your time conversing with hacks you tend to pick up their careless lingo. I’m sure the question is about whether or not the relationship is statistically significantly different from zero. And I’m also quite certain that the auditor could point to the use of R2 by climate scientists and say, Aha, they should just be reporting a correlation coefficient! I agree with you, but when arguing I think it’s important to focus on meaning instead of word usage (although if someone intentionally chooses problematic words, it’s fair to call them on it).

To me there are enough other red flags over there to warrant visiting less frequently.

Not just statistical, but elementary-physics as well: http://atmoz.org/blog/2008/08/08/the-anatomy-of-a-climateaudit-post/

Here is a very good summary of the history of the Hockey stick; http://bishophill.squarespace.com/blog/2008/8/11/caspar-and-the-jesus-paper.html

U.S. Senate Committee on Environment & Public Works
Hearing Statements
Date: 12/06/2006


I had another interesting experience around the time my paper in Science was published. I received an astonishing email from a major researcher in the area of climate change. He said, “We have to get rid of the Medieval Warm Period.”

The `Hockey Stick’:
A New Low in Climate Science

by John L. Daly http://www.john-daly.com/hockey/hockey.htm

Sound like anyone we know?

You probably have met an Internet troll – even if you don’t know the term. They are the juvenile cretins who infest Internet message boards, taunting the earnest types chatting away about Gossip Girl, or Barack Obama, or Scientology.

Their method is to post wilfully ignorant, insulting messages, then sit back and enjoy the righteous, impotent fury aroused among the true believers.

Trolling is an inherently nihilistic activity – which is why most trolls tend to be adolescent males, the sort of specimens who would otherwise entertain themselves by using bathroom graffiti to libel the sexual habits of high-school classmates.

- from http://www.canada.com/vancouversun/news/editorial/story.html?id=1b292856-f9f1-4eb8-a7f1-9e78b5e6cefb

Bishop Hill wrote the following in a well written history of the hockey stick.

“That the statistical foundations on which they (Amman, Wahl, and Mann) had built this paleoclimate castle were a swamp of misrepresentation, deceit and malfeasance was, to Wahl and Amman, an irrelevance. For political and public consumption, the hockey stick still lived, ready to guide political decision-making for years to come.”

One comment called the hockey stick guttersnipe science.