A new paper in the Proceedings of the National Academy of Sciences, concluding that the buildup of human-generated greenhouse gases could leave a profound millenniums-long imprint on climate and sea levels, focuses on a characteristic of global warming that the public, and many policymakers, have not absorbed — at least according to John Sterman at M.I.T.
That characteristic is the "bathtub effect" behind the human-amplified greenhouse effect. Dr. Sterman, a prominent analyst of risk perception and management at the Sloan School, has devised various tools akin to flight simulators to help corporate leaders understand the nature of a variety of problems and choose among various remedies. He recently turned this approach to climate, which he says bears much more resemblance to deficit spending and the national debt than it does to 20th-century-style pollution problems like acid rain.
Basically, the atmosphere is like a bathtub with a partially opened drain. Carbon dioxide from burning fuels and forests is flowing in twice as fast as it is being absorbed by plants and the ocean, and some of those "sinks" are in fact getting saturated, it appears, meaning that the "drain" is clogging a bit. (More on "CO2's Long Goodbye".)
In a tub, this is a recipe for a flood. In the climate system, Dr. Sterman says — echoing many climate scientists — it is a loud message that a prompt start is needed in curbing and then cutting emissions if you want to cut the chances of passing dangerous thresholds. He recently wrote a Policy Forum paper in Science reviewing his and other research on widespread misunderstanding of this kind of risk, including a 2007 study he was a co-author of in which 84 percent of 212 M.I.T. participating grad students drew curves for proposed emission trends that would result in concentrations continuing to climb.
"The erroneous belief that stabilizing emissions would quickly stabilize the climate supports wait-and-see policies but violates basic laws of physics," Dr. Sterman concluded.
I sent him the study from the Proceedings, which was led by Susan Solomon, who also led a five-year review of science that culminated in the main report in 2007 by the Intergovernmental Panel on Climate Change. His response is worth reading, and is included in toto below.... Read the full article