Roy W. Spencer (Climate Confusion, 2008) is a climatologist. He is skeptical of the theory that most of global warming is caused by humanity, or that we understand the climate system and our future technological state well enough to make predictions of global warming, or that we need to reduce fossil fuel use now. Yes, he says, global warming is happening. How much of it is due to natural processes verses human activity? How bad will global warming be in the future? What can we do about it? One of his points is that any theory regarding global warming must remain a theory. Yes, he says, warming has occurred in the last thirty years. Yes, greenhouse gas concentrations in the atmosphere have increased. Yet, this does not suggest cause and effect. He has an interesting chapter on how weather works. For many of us non-scientists, this is a helpful refresher course. The sun heats the earth, of course. Infrared light cools the earth as it moves through the atmosphere and escapes the earth. Global warming theory involves how infrared energy is redistributed within, and lost by, the surface and atmosphere. Water vapor accounts for 70-90% of the natural greenhouse effect. The other components are carbon dioxide and methane. Clouds have a large greenhouse effect, but clouds are ice crystals, and thus, not a gas. One of his main points is that weather cools the surface of the earth well below what it would be if sunlight and the greenhouse effect had their full way. The flow of heat is what we call weather. The second law of thermodynamics states that energy tends to flow from where there is more to where there is less. Evaporation is the primary means for cooling the earth. Evaporation removes heat from the surface, but it helps to heat the earth when the vapor becomes part of the atmosphere. He describes the weather system as a circulation system, constantly heating and cooling, managing the flow of heat.
In Chapter 4, he deals with how global warming allegedly works. He focuses on carbon dioxide. For every 100,000 molecules of air, 38 of them are carbon dioxide. This small amount is why it is one of the “trace gases.” There is not much of it. Humanity is adding one molecule of carbon dioxide to every 100,000 molecules of air every five years or so. Where the increase of carbon dioxide can be measured, whether near a large city or on an isolated island, the increases are quite constant, suggesting to him that human activity has a small influence. He makes his basic proposition quite clear: “I believe it makes more sense to assume that the Second Law of Thermodynamics is the ultimate guiding principle in climate sensitivity, and that the climate system changes in ways that act to rid the system of excess heat.” In essence, the earth has a thermostat called precipitation. Again, yes, human beings are producing carbon dioxide as a result of their use of fuels. Yes, carbon dioxide content of the global atmosphere has been slowly increasing. Of the 38 molecules of carbon dioxide for each 100,000 molecules of air, humanity is adding about one molecule of carbon dioxide every five years. However, that one molecule should be twice as much. It is “missing,” due to the fact that for plants, it is “food,” resulting in increasing vegetation growth rates around the world. Yes, carbon dioxide is a greenhouse gas, albeit a trace gas, for it keeps some infrared radiation from escaping from the earth. Yet, there are also cooling effects due to weather patterns. In the past century, the earth may be about one degree warmer, with 40% of the increase occurring before 1940.
Speaking of carbon dioxide as a trace gas, and noting how many CO2 molecules exist for every 100,000 molecules of air, etc, is technically true. However, it is a literally trick that is, unfortunately, one reason why our science education & communication is failing the general public.
ReplyDeleteThe obvious intent is to think, "Jeez! Only 1 extra CO2 every 5 years? What's the big deal?" (Never mind that even 100,000 molecules is almost too little for us to comprehend). No responsible adult would give their child "only" 0.5 mg of lead each day with their cereal. Ditto with the damage to the ozone layer - I've read several editorials about how the hole "disappears" for half the year, how if it were at sea level, it'd only be a few mm thick, etc. These are all stats that, while technically true, are conveyed unscientifically by irresponsible writers/reporters. What is indisputable is the global CO2 levels are higher now (even though they are "trace") than they've been for 800,000 years, and probably for millions more.
In the ozone example, frightened industry cast doubt on the science from the beginning, not because they were interested in truth, but in profits. They were able to take the scientific observations and repeat them without the proper context. The rest is history - a global agreement, regulation, and a reduction delivered at costs far below initial estimates. The same pattern can be seen for particulates, SOx, NOx, etc. This information is all publicly available.
Thus, many issues that are well-known or beyond dispute are given extra doubt by unscientific reporting of the data. Unfortunately for scientists, their work is not easily conveyed on 90-sec evening news spots; this seems to be an inherent problem. Maybe one can blame the public for not taking the time to think, or their teachers for not teaching them. The more obvious truth we know from psychology is that people want data to fit their existing worldview or bias; this is why conservative voters tend to "believe" in global warming less, and liberals more. Meanwhile, both sides accuse the other of ignoring the data :)
But - this looks like an interesting minority report. I will add it too my reading list... and as his subtitle says, I hope to see that he really does care about the poor!