Weather Or Not

Our latest column in the N.Y. Times Magazine is about the weather. Exciting, huh? Specifically, it’s about how some economists are studying the weather itself (particularly the potential impact of global warming) and how others use weather as an instrumental variable to measure various human behaviors, including crime, war, rioting, etc. This column is more of a review of the literature than most of our previous columns. But the literature in this case was so diverse and interesting that it seemed well worthwhile. Comments welcome below. And, as always, we’ve posted the underlying academic research elsewhere on this site.


Weather triggers unconscious reactions. The linkage seems genetic but not necesserily unchangeable.

What worked for Africa in terms of production drop leading to wars, might not work in a decade as circumstances will change (and they will improve agriculture etc).

For the U.S. Maiami and Phoenix with precisely hot, humid and hard to breath climate, are considered retirement hotbeds. A contradiction with the cited paper.

John Bullock

In this vein, see "Blind Retrospection," in which Chris Achen and Larry Bartels argue that incumbent political parties regularly suffer because of bad climactic conditions. In particular, they suggest that Gore lost 2.8 million votes in 2000 because some places received too much or too little rain.


My letter to the NY Times:

Stephen Dubner and Steven Levitt, the creators of "Freakonomics," have entertained us with clever, quirky stories about markets and incentives, taking economic logic to places where it rarely goes. Unfortunately, they have strayed back onto the beaten path in "The Price of Climate Change" (NYTimes Magazine, Nov 5). They fall far short of understanding this well-researched topic, leaning too heavily on a study by two other economists which is definitely not the last word on the subject. That study projects a 4% increase in US agricultural profits due to global warming by the end of this century. According to Dubner and Levitt, "This hardly fulfills the doomsday fears conjured by most conversations about global warming."

The study discussed by Dubner and Levitt uses one of several possible methods for projecting the effects of climate change on US farm incomes, and relies on climate projections released in 1997. Climate science has progressed rapidly since 1997, and the newest projections are much more ominous. In addition, the paper explicitly states that it is looking only at the effects of changes in average temperature and rainfall, and excludes the effects of extreme weather events such as heat waves, storms, and droughts. But at least for the next few decades, extreme weather events will be the most important and painful impacts of climate change. New Orleans was not flattened by small changes in average temperatures and precipitation. A study that ignores extreme weather events hardly refutes anyone's (well-founded) fears about climate change.

Frank Ackerman
Global Development and Environment Institute
Tufts University
44 Teele Ave.
Medford MA 02155, USA




After I read "Freakonomics", the first thing that came to my mind was wondering if some of the same tools could be used to settle whether there is such a thing as the alleged crisis of global warming. I found Michael Crichton's fictional (albeit highly researched) "State of Fear" fascinating, especially in concert with "Discover" magazine's interview with meteorologist William Gray in the magazine's September 2005 issue. I quote:

A few years ago, you almost called it quits because you'd lost so much funding. What made you continue?

G: I don't have the budget that I had, so I have cut my project way back. I am in retirement. I'm still working every day, but I don't teach and I don't have as many graduate students and as much financial need. I've got a little money from Lexington Insurance out of Boston, and I have some National Science Foundation money. For years I haven't had any NOAA, NASA, or Navy money. But I'm having more fun. Right now I'm trying to work on this human-induced global-warming thing that I think is grossly exaggerated.

You don't believe global warming is causing climate change?

G: No. If it is, it is causing such a small part that it is negligible. I'm not disputing that there has been global warming. There was a lot of global warming in the 1930s and '40s, and then there was a slight global cooling from the middle '40s to the early '70s. And there has been warming since the middle '70s, especially in the last 10 years. But this is natural, due to ocean circulation changes and other factors. It is not human induced.

That must be a controversial position among hurricane researchers.

G: Nearly all of my colleagues who have been around 40 or 50 years are skeptical as hell about this whole global-warming thing. But no one asks us. If you don't know anything about how the atmosphere functions, you will of course say, "Look, greenhouse gases are going up, the globe is warming, they must be related." Well, just because there are two associations, changing with the same sign, doesn't mean that one is causing the other.

With last year's hurricane season so active, and this year's looking like it will be, won't people say it's evidence of global warming?

G: The Atlantic has had more of these storms in the least 10 years or so, but in other ocean basins, activity is slightly down. Why would that be so if this is climate change? The Atlantic is a special basin? The number of major storms in the Atlantic also went way down from the middle 1960s to the middle '90s, when greenhouse gases were going up.

Why is there scientific support for the idea?

G: So many people have a vested interest in this global-warming thing-all these big labs and research and stuff. The idea is to frighten the public, to get money to study it more. Now that the cold war is over, we have to generate a common enemy to support science, and what better common enemy for the globe than greenhouse gases?

Are your funding problems due in part to your views?

G: I can't be sure, but I think that's a lot of the reason. I have been around 50 years, so my views on this are well known. I had NOAA money for 30 some years, and then when the Clinton administration came in and Gore started directing some of the environmental stuff, I was cut off. I couldn't get any NOAA money. They turned down 13 straight proposals from me.

So: Can economics tools help cut through the noise?