Ernest Thoughts, by Ernest B. Cohen
The Discovery of Global Warming
By Spencer R. Weart
May 1, 2011

     Recently, I went through the attic bookcases, searching for some books for our grandchildren to read.  I was looking for The Good Soldier Schwiek and Earth Could be Fair by Pierre Van Passen, but didn't find them.  Instead, I found the book, The Discovery of Global warming, by Spencer A. Weart, copyright 2008.  It is a revised and expanded edition of a 2003 book.  My copy is signed by the author which implies that we met in person at a conference or lecture, but I don't remember.  It would be impossible to condense 204 pages down to one, so just some thoughts on reading it.
    
    This book relates the history of climate science.  It started with the question about ice ages; why did they come and go.  Then, why is the Earth at its present average temperature?  Based upon the physics of radiation, the Earth, without an atmosphere should be much colder.  What keeps the Earth at a nice temperature for life?  It is the presence of so called "green house" gases in the atmosphere, which partially block heat radiation to space.  Fine dust particles in the atmosphere, such as put forth by volcanic eruptions or industrial activity, can either warm or cool the earth.

     The climate system is very complex, with many feed back loops, both positive and negative.  For example, melting ice caps change the Earth's albedo, so that it absorbs more solar radiation.  Water vapor is a very powerful green house gas, and warmer air holds more water vapor.  The average temperature can stay cold for ages, and then suddenly shift to warm, and vice versa.

     Because of the complexity of climate and weather, the best theories are now in the form of computer simulations.  Until recently, there were no computers with sufficient power to handle these computations.  Like any scientific theories, these have to be checked against measured data, and corrections made for relations left out of simplified models.  The necessary data is expensive to collect, and was insufficient until very recently.

    So one point for the climate change deniers: yes, a whole host of scientists were asking, and getting more funding for their work.  But the energy industries have much more to gain from obfuscating climate science.  They are behaving like the tobacco industry that tried to cast doubt on solid statistics.  This morning I heard a radio commercial asking people to tell their elected representatives to remove requirements for renewable electrical generation, on the basis of cost.  This "short term, bottom line" philosophy is harming America.  In the short term, we can save a lot of money by not doing many things, but in the long term, not doing these things now will cost a lot more.  How much can taxes be reduced if there were no public education?  Without a strong technology base, the American economy would be reduced to competing with the Third World for cheap labor work.

     I recommend this book to climate change deniers.  I suspect that many of them also doubt evolution; if science threatens their world view, they merely ignore science.  In extreme cases, such as: Galileo and the Catholic Church, they use political power to silence scientists or edit their findings.  In the last year of the Clinton administration, a panel of EPA scientists came to Philadelphia to explain how climate change would probably affect this area.  It is not simply, a little less snow to shovel, it is more storms and more violent storms.  Warmer air holds more moisture, and condensation of this moisture powers storms.  The recent spate of tornados in the southern states is a clear warning of what this could mean.

     After life itself, climate and weather are the most complex phenomena that science has tackled.  There are at least a half dozen different disciplines involved.  Isotope studies from ancient ice cores are important, and so are minor changes in the Earth's orbit.  One of the key points that deniers of anthropogenic warming quote is a minor cooling in the late 50s and early 60s.  Careful analysis of the data indicates this was due to increased anthropogenic aerosols (air born particles) which absorbed sunlight, and countered the effect of increased carbon dioxide.  If we go back to geocentric versus solarcentric universe controversies, there were some unexplained anomalies in some of the planetary orbits, but these bothered astronomers less than the need to have God push Saturn and Jupiter every once in a while to account for retrograde motions.  Centuries later, detailed analysis of these anomalies led astronomers to predict the existence of other planets, and determine their orbits.  The first of these new planets, Uranus, was observed by Sir William Herschel.

     Likewise, minor discrepancies in climate data have challenged scientists to look into many interesting effects.  What happens to green house gases in the atmosphere?  Carbon dioxide is eventually absorbed by the ocean, which changes the ocean acidity (pH), and in turn affects oceanic life.

      Another point is to determine the potential effect on humans if we get this wrong.  Aside from the reputation of the various churches, accepting wrong conclusions in the cases of a solar centric universe, or, intelligent design, has minimal consequences.  Not dealing with global climate change will leave us unprepared for flooding of coastal cities, and food shortages as some of the major grain growing areas will suffer drought, and others will be damaged by too much rain.  Cheap energy from fossil fuels for the next decade or so, is a small thing to forgo if it comes with later collapse of civilization.  I think that most of us would rather eat then drive cars if the choice came to that.