Editorial: Enriching a muted discussion

July 3, 2009
Three recent developments—one scientific and two polemic—should enrich discussion about human activity and climate change.

Three recent developments—one scientific and two polemic—should enrich discussion about human activity and climate change. In popular media and much of government, however, no such discussion exists. That this is so provides more cause for fear than does whatever global warming may result from the use of fossil energy.

The scientific development is publication of a paper in the American Geophysical Union’s Journal of Geophysical Research suggesting that nonhuman influences account for most observed warming over the past 50 years. Australian researchers J.D. McLean of Applied Science Consultants, C.R. de Freitas of the University of Aukland, and R.M. Carter of James Cook University found a close relationship, with a 5-7 month delay, between the Southern Oscillation-El Nino phenomenon and two temperature records covering 1950-2008 and 1980-2008.

“Overall the results suggest that the Southern Oscillation exercises a consistently dominant influence on mean global temperature, with a maximum effect in the tropics, except for periods when equatorial volcanism causes ad hoc cooling,” the researchers write in an abstract. The relationship “shows the potential of natural forcing mechanisms to account for most of the temperature variation.”

Squelching doubt

According to another development, the researchers should expect trouble. In a paper entitled “Climate Money” published by the Scientific & Public Policy Institute, Washington, DC, Australian science writer Joanne Nova describes a well-funded political mechanism dedicated to squelching doubt about the need for urgent warming responses.

“The large expenditure in search of a connection between carbon and climate creates enormous momentum and a powerful set of vested interests,” Nova writes, asserting that the US government has spent more than $79 billion since 1989 on policies related to climate change. A paucity of funds and sometimes abusive resistance await those who question the carbon-climate link. “In this scientific debate,” she argues, “one side is gagged while the other side has a government-funded media campaign.”

The existence of this public-relations snare is nothing new. Massachusetts Institute of Technology climatologist Richard Lindzen is among scientists who have complained about it (OGJ, Apr. 24, 2006, p. 19). With the US Congress deliberating cap-and-trade legislation with potential to overhaul US economic patterns, however, concern about the quality of debate seems hugely in order.

The third development is a triumph of packaging: a brochure published by the George C. Marshall Institute entitled “The Cocktail Conversation Guide to Global Warming.” While breaking no new argumentative ground, the brochure cleverly compresses into one place several vital points that too seldom receive attention.

It notes, for example, that the ballyhooed “scientific consensus” is a mischaracterization of summaries written by government appointees of complex scientific reports produced every 5 years by the United Nations Intergovernmental Panel on Climate Change (IPCC). “These summaries leave out the assumptions and uncertainties contained in the longer assessment reports,” the brochure says.

The brochure also raises questions about warming assumptions fundamental to the politics of behavior-changing response. Although emissions of greenhouse gases increased in the last half of the 20th century, global surface temperatures haven’t risen since about 1998. And ocean temperatures, which may more accurately represent planetary conditions, have been monitored systematically only recently and show little, if any, recent warming.

Unanswered question

And how many people know how little warming can be directly attributable to the relatively slight human contribution to all carbon dioxide in the atmosphere? The brochure notes that the potential for troublesome warming depends on amplification of CO2–induced warming by related changes in cloud cover and water vapor. IPCC computer models all assume strong secondary warming from decreased cloud cover and increased water vapor in the atmosphere. Yet various physical observations suggest that net cloud and water-vapor changes might, on balance, have the opposite effect.

In fact, the Marshall Institute brochure calls uncertainty about cloud and water-vapor feedbacks “the most important question in global warming research today.” Yet the popular wisdom is that the science is “settled,” the debate over. And a determined effort remains in progress to raise energy costs painfully before a muted discussion can raise any more contrary questions.