By Kennedy Maize
Washington, D.C., August 1, 2011 — A recent article in the peer-reviewed journal Remote Sensing raises a profound challenge to the conventional wisdom about global warming predictions based on global circulation computer models. The paper by Roy W. Spencer and William D. Braswell of the University of Alabama at Huntsville shows that Earth’s atmosphere is better at releasing energy to space when the climate warms than the computer models assume.
Spencer’s analysis is based on data from NASA’s Terra satellite. Spencer, long a prominent global warming skeptic, was in charge of the NASA satellite temperature monitoring for many years and continues that oversight as a researcher at the university’s Earth System Science Center.
According to Spencer, the models show climate warming that is faster than the atmospheric data demonstrate. The issue is “feedback,” a key element of dispute between advocates of the computer models and their warming forecasts and the skeptics such as Spencer and MIT’s Richard Lindzen. Do the physical mechanisms at work in the climate reinforce warming or mitigate it? “The satellite observations suggest there is much more energy lost to space during and after warming than the climate models show,” says Spencer. “There is a huge discrepancy between the data and the forecasts that is especially big over the oceans.”
Spencer’s work shows that the atmosphere releases more energy than the models incorporate and release it faster. The models are based on the climate absorbing solar energy until the warming peaks. The satellite data shows the climate shedding energy well before the warming event reaches a peak. “At the peak,” Spencer says, “satellites show energy being lost while climate models show energy still being gained.”
It’s all well-understood physics, argues Spencer: The first law of thermodynamics, aka the conservation of energy. “We show it actually holds for global-average temperature changes: A radiative accumulation of energy leads to a temperature maximum…later. Just like when you put a pot of water on the stove, it takes time to warm. But while it only takes 10 minutes for a few inches of water to warm, the time lag of many months we find in the real climate system is the time it takes for several tens of meters of the upper ocean to warm. We showed unequivocal satellite evidence of these episodes of radiant energy accumulation before temperature peaks…and then energy loss afterward. Energy conservation cannot be denied by any reasonably sane physicist.”
The thrust of Spencer’s findings is to complicate the mix of forces that drive the climate, which the computer models simplify, or over-simplify in Spencer’s view. “The main finding from this research,” says Spencer, “is that there is no solution to the problem of measuring atmospheric feedback, due mostly to our inability to distinguish between radiative forcing and radiative feedback in our observations.”
The important result of Spencer’s latest work is that it shows that the climate models, on which all of the doomsday predictions and policy prescriptions are based, are incapable of verification. In his blog, Spencer writes, “Did we ‘prove’ that the IPCC climate models are wrong in their predictions of substantial future warming? No, but the dirty little secret is that there is still no way to test those models for their warming predictions. And as long as the modelers insist on using short term climate variability to ‘validate’ the long term warming in their models, I will continue to use that same short term variability to show how the modelers might well be fooling themselves into believing in positive feedback. And without net positive feedback, manmade global warming becomes for all practical purposes a non-issue. (e.g., negative cloud feedback could more than cancel out any positive feedback in the climate system).”