Letters

Economics of climate change

And so there is another "urgent plea" on global warming by a group of distinguished scientists (C&EN, June 28, page 44). Furthermore, in C&EN, reporters and correspondents have endorsed that the debate will be settled through science ("Global Climate Change and Citizen Chemists," C&EN, March 29, page 45; "Global call to arms," C&EN, June 28, page 5). As a chemist, I am strongly inclined to be on that bandwagon. But, and it is a large but, there are others in the cacophony, including the economists.

Generally, scientists and economists are separated by a gulf of mutual incomprehension. The economist is determined to value everything, including the environment, and speaks in a jargon incomprehensible to scientists--who return the compliment. Nonetheless, economists have said much to be heeded concerning global climate change.

In his 2001 book, "The Skeptical Environmentalist," Bjørn Lomborg said, in so many words, that mitigation now is a bad investment. His data were almost entirely from governmental and intergovernmental reports. More recently, climate change was examined by the Copenhagen Consensus Project, a joint undertaking of Denmark's Environmental Assessment Institute (headed by Lomborg) with the cooperation of the Economist. The project aims to consider, and to establish priorities, among a series of proposals for advancing global welfare. (A full description of the project, along with a list of its distinguished participants from around the world, can be accessed on http://www.economist.com. A book containing the full set of papers for the project is forthcoming.)

The most distinguished participants (three Nobel Laureates and perhaps a number of soon-to-be laureates) formed a final panel to prioritize the issues based on the economics--mostly cost-benefit ratios. For comparison, rated "very good" was control of HIV/AIDS and providing micronutrients in food to abate malnutrition. Three climate-change options--"optimal" carbon tax, the Kyoto protocol, and value-at-risk carbon tax--made the bottom of the list of 17 specific proposals. The climate-change proposals were rated "bad," meaning the costs were thought to exceed the benefits.

The challenge paper on climate change was written by William Cline of the Centre for Global Development. Cline is pro-Kyoto and favors even stronger measures to abate carbon emissions than the protocol requires. He and his colleagues were unable to convince the panel.

Now what, fellow scientists? How can our scientific open minds ignore these and other economic arguments floating around the world? How do we bridge the gulf between climate science and economics? I surely have no easy answers, but I am convinced we must heed the valuation arguments. To do otherwise will consume resources that could be directed elsewhere, such as to chemical research.

Harvey Alter
Frederick, Md.

Contents under pressure

In the nice description of Joseph L. Gay-Lussac's contributions to ballooning and the study of gases in Newscripts, the author states: "Gay-Lussac, a pioneer of hot-air ballooning, discovered the second ideal gas law: The volume of a given mass of gas is directly proportional to its temperature" (C&EN, June 21, page 56).

I wish to point out that, strictly speaking, the statement is true only if the pressure is kept constant. Assuming that the "first" ideal gas law is Boyle's law--the pressure of a given mass of ideal gas is inversely proportional to its volume at constant temperature--both of these laws can be easily shown to be special cases of the familiar equation of state for an ideal gas, namely, PV = nRT. Almost every textbook of general chemistry and physical chemistry discusses the gas laws and equation of state. In particular, J. R. Partington provides an interesting historical discussion and "derivation" of the equation of state from the laws of Boyle and Charles/Gay-Lussac in his classic text, "A Text Book of Inorganic Chemistry." Linus Pauling's "General Chemistry" also has a succinct section discussing the gas laws.

Rama Viswanathan
Beloit, Wis.