Please read the whole article at the source. There’s a lot more detail, diagrams, pictures, and basically just a lot to learn there. The excerpts below are just a few highlights I snipped out.
Global Warming and Nature’s Thermostat
by Roy W. Spencer
Roy W. Spencer received his PhD in meteorology at the University of Wisconsin-Madison in 1981. He has been a Principal Research Scientist at the University of Alabama in Huntsville since 2001, before which we was a Senior Scientist for Climate Studies at NASA’s Marshall Space Flight Center where he received NASA’s Exceptional Scientific Achievement Medal. Dr. Spencer is the U.S. Science Team leader for the Advanced Microwave Scanning Radiometer flying on NASA’s Aqua satellite. His research has been entirely supported by U.S. government agencies: NASA, NOAA, and DOE.
A Summary, and the Future
It is now reasonably certain that changes in solar radiation cause temperature changes on Earth — for instance, the 1991 eruption of Mt. Pinatubo caused a 2% to 4% reduction in sunlight, resulting in two years of below normal temperatures. It is not so obvious, however, that small changes in the Earth’s infrared cooling from mankind’s burning of fossil fuels will do the same. This is because the Earth’s natural greenhouse effect is mostly under the control of weather systems: specifically, precipitation systems. Either directly or indirectly, these systems determine the moisture (water vapor and cloud) characteristics for most of the rest of the atmosphere.
Precipitation systems thus act as a thermostat, causing cooling when temperatures get too high (and warming when temperatures get too low). It is amazing to think that the ways in which tiny water droplets and ice particles combine in clouds to form rain and snow could determine the course of global warming, but this might well be the case.
I believe that it is the inadequate handling of precipitation systems — specifically, how they adjust atmospheric moisture contents during changes in temperature — that is the reason for climate model predictions of excessive warming from increasing greenhouse gas emissions.
I predict that further research will reveal some other cause for the warming we have experienced since the 1970’s — for instance, a change in some feature of the sun’s activity. In the meantime, a high priority research effort should be the study of changes in precipitation systems with changes in temperature — especially how they confer moisture charateristics to the atmosphere as air is continuously recycled through them.
Fortunately, we now have several NASA satellites in Earth orbit that are gathering information that will be immensely valuable for determining how the Earth’s climate system adjusts during natural temperature fluctuations. It is through these satellite measurements of temperature, solar and infrared radiation, clouds, and precipitation that we will be able to test and improve the climate models, which will then hopefully lead to more confident predictions of global warming.
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