But one of the difficulties I found in examining the views of climate skeptics is that they are scattered widely in blogs, talks, and pamphlets. Then, I saw an opinion piece in The Wall Street Journal of January 27, 2012, by a group of sixteen scientists, entitled “No Need to Panic About Global Warming.” This is useful because it contains many of the standard criticisms in a succinct statement. The basic message of the article is that the globe is not warming, that dissident voices are being suppressed, and that delaying policies to slow climate change for fifty years will have no serious economic or environment consequences.
My response is primarily designed to correct their misleading description of my own research; but it also is directed more broadly at their attempt to discredit scientists and scientific research on climate change.
So Nordhaus then addresses several questions
• Is the planet in fact warming?
• Are human influences an important contributor to warming?
• Is carbon dioxide a pollutant?
• Are we seeing a regime of fear for skeptical climate scientists?
• Are the views of mainstream climate scientists driven primarily by the desire for financial gain?
• Is it true that more carbon dioxide and additional warming will be beneficial?
As I will indicate below, on each of these questions, the sixteen scientists provide incorrect or misleading answers. At a time when we need to clarify public confusions about the science and economics of climate change, they have muddied the waters. I will describe their mistakes and explain the findings of current climate science and economics.
You’d think that was a valuable contribution. Now Bob Murphy has shown that Nordhaus was a bit naughty in his explanations.
Nordhaus identified six allegedly misleading claims made by the skeptics in their WSJ article, and proceeded (in his mind) to dismantle their bogus views. In the interest of brevity, I will in this post focus on just four of the claims. As we’ll see, it is Nordhaus who is playing fast and loose with the readers. Many of the objections raised by the skeptics are indeed legitimate.
I particularly enjoyed this bit of the Murphy critique.
It’s also interesting that Nordhaus invites his readers to not get caught up in the tiny details, and instead to take a step back and survey the grand picture of global temperatures. I agree. In that spirit, I suggest it can be misleading to focus—as Nordhaus does—on deviations of temperatures. Instead, let’s look at a graph of actual global temperatures, using the same three standard data sets that Nordhaus used for his own graph. (All we’re doing here is adding a base of 14 degrees Celsius to the deviations that Nordhaus plots.) The graph looks like this:
SOURCE: Data sets cited by Nordhaus, with 14C base global temperature added to deviations.
Seen in this light, it’s still true that temperatures of the last decade are higher than at any point since the late 19th century, yet this chart isn’t nearly as scary as the one Nordhaus showed.
To be clear, I’m not accusing Nordhaus of anything deceptive regarding the format of his temperature chart. There are good reasons that climate scientists tend to work with temperature deviations, rather than absolute levels. Furthermore, without more information to guide our charting decisions, choosing a y-axis range of 0–20 Celsius degrees—as I’ve done in the graph above—is just as arbitrary as Nordhaus implicitly choosing a range of 14–15 degrees in the graph he used. Even so, when experts such as Nordhaus are presenting their material to the layperson, these nuances can get lost in the shuffle. Nordhaus thought his readers would “benefit from stepping back and looking at the record of actual temperature measurements,” and I agree.
I agree too. That graph is awesome and you’d have seen something like it before. Alex Robson and I created a graph like that in 2007.
Update: Due to popular demand I’m showing the second graph updated to the end of 2011.