I think there is still a controversy over how much economic development contributes to global warming. NASA scientist Keith Schatten and Douglas Hoyt have made a compelling case in "The Role of the Sun in Climate Change", Oxford University Press, 1997 that there is a very good correspondence between solar fluctuations and global warming. Also John Stossel interviewed scientists at the Smithsonian Astrophysical Laboratory about two years ago on 20/20 (I have a copy of the program) in which they presented compelling data that the earth was much warmer during the Roman Empire era up until about 900 AD when we began going into the little ice age. The coldest period of the little ice age was around 1800-1810. Since then the earth has been warming but we are still below the median temperature of the last 2000 years. During the 1970's many scientists were warning about global cooling due to CO2 because the earth experienced small cooling during the 1970's (which by the way also corresponded to solar data) including an article by Carl Sagan in Parade Magazine. When it became clear the earth was warming significantly during the 80's and 90's global warming due to CO2 was put forth as the cause. I think both sides of the argument have an axe to grind with much federal funding for carbon sequesterization that would disappear if the sun was found to be mainly responsible as well as funding for various "green" movements who has pushed the Kyoto Accord versus the extraction industries. Clear Skies Don -----Original Message----- From: utah-astronomy-bounces+djcolton=piol.com@mailman.xmission.com [mailto:utah-astronomy-bounces+djcolton=piol.com@mailman.xmission.com] On Behalf Of Michael Carnes Sent: Thursday, March 09, 2006 8:41 AM To: Utah Astronomy Subject: Re: [Utah-astronomy] Science Fair One thing to keep in mind, Joe. The earth has been busy sequestering atmospheric carbon since at least the Permian era. That sequestering takes the form of coal, petroleum, natural gas and methane hydrate (in the deep oceans). Humanity has been busy releasing all of that carbon (by burning fossil fuels) and has undone the work of hundreds of millions of years in just a couple of centuries. How can that not have a significant effect? It is certainly true that the sun's luminosity fluctuates over time. Precession and changes in earth's magnetic field may cause climate change as do movements of the tectonic plates. But humanity's denial of its own part has more to do with discomfort at what lies ahead. A large and increasing number of scientists (especially those not being financed by the extraction industry) are convinced that we play a noticeable role in these changes.
My son and I have been politely disagreeing about that for a while. I maintain global warming is occurring and that probably we have something to do with it -- but it's been warming since the end of the Pleistocene and our contribution may be minor. He takes the position we're to blame. Thanks, Joe
_______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.utahastronomy.com