The Right Coast

December 21, 2004
 
Global Warming
By Mike Rappaport

A great article in the local newspaper on global warming written by a climate scientist. Here are some excerpts:

Virtually everyone agrees that more carbon dioxide causes a warming tendency – the real question is, how will the climate system respond?

For instance, the warming due to just carbon dioxide increases is predicted by climate models to be approximately doubled by increasing levels of water vapor, the atmosphere's primary greenhouse gas. But what determines the level of water vapor in the atmosphere? It is a balance between (1) evaporation from the surface, and (2) removal by precipitation systems. Since science doesn't yet understand how precipitation systems will respond to a warming tendency (for instance, warmer tropical systems are known qualitatively to be more efficient at removing water vapor than cooler high-latitude systems), it has virtually ignored research related to the efficiency of precipitation systems, and has instead emphasized the "increased evaporation" part of the equation. Quantitative knowledge of this "positive water vapor feedback" effect thus requires knowledge that we currently do not have. The effects of clouds are even more uncertain. What we do know, though, is that all of the weather that makes up climate is working with one goal: to get rid of excess heat.

The "new ice age" scare of the 1970s should teach us something about statements coming from scientific bodies: that even in scientific reports, scientists sometimes get a little carried away with their theories. This explains in part why scientists' pronouncements are not blindly accepted by the public anymore. Additionally, the most authoritative reports, produced by the IPCC, have been notorious for downplaying or outright ignoring uncertainties in their summaries for policy-makers (the only part a congressional staffer is likely to read). Combined with the biased influence of the principals leading the IPCC report process, and the United Nations' own agenda for future political influence ("Agenda 21"), it is easy to see how the scientific message can get distorted and misused.

Furthermore, also unstated by Oreskes is the widespread practice by U.S. funding agencies of only funding research that implicitly accepts the putative global warming paradigm. Research funds from Congress depend on threats to the populace, and as long as there are possible climate mechanisms that could make global warming worse, funding is enhanced. I am not suggesting widespread deceit or questionable motives – only that public funds are usually made available to study problems, not non-problems.
So, despite the claim that there is a consensus of scientists who believe there is global warming caused by humans, I continue to be skeptical because the consensus is overstated, it ignores areas of uncertainty, and there are incentives for the scientists to support the so called consensus.