Dale Courtney’s May Day column, “No one is a climate change denier,” needs a lot of corrections.At least he admits the climate is changing.However, he fails to acknowledge that right now it is changing 10 times faster than in many thousands of years.No proof that carbon dioxide causes global warming?In the 1860s John Tyndall first showed that CO2 absorbs radiation and then re-emits this energy as long-wave radiation – which we know as thermal radiation, or heat. A few decades later Svante Arrhenius, in a seminal paper, recognized the potential of CO2 to hold the heat that is produced by incoming solar radiation inside of Earth’s atmosphere rather than allowing that heat to escape into space—just like adding another blanket when you’re in bed. This original hypothesis has since been supported by over 100 years of research, making it an accepted fact of atmospheric physics today. In recent times, it has been supported by empirical evidence using modern scientific equipment to measure the specific wavelengths of heat radiation. Land-based equipment shows that other than water vapor, the greatest amount of heat emitted from the atmosphere back toward Earth’s surface, is at specific wavelengths corresponding to CO2, methane and ozone—the major greenhouse gases. Additionally, satellite-based equipment that measures the radiation at these wavelengths escaping Earth’s atmosphere shows that it has been decreasing over recent decades of atmospheric warming. We know that these three gases absorb and then emit heat at these thermal wavelengths.We also know that as these molecules build up in Earth’s atmosphere because of, among other things, the burning of coal and oil, heat at these specific wavelengths is increasingly being reflected back to Earth while decreasingly escaping our atmosphere.That these three molecules are greenhouse gases — absorbing Earth’s reflected heat and re-emitting it back to Earth — is today a widely accepted fact based on this and other solid scientific evidence. To imagine otherwise is dangerous. Ninety-seven percent of climate scientists agree that it is extremely likely the trends of climate-warming over the past century are due to human activities.Almost all of the leading scientific organizations worldwide have issued public statements endorsing this position.This is overwhelming – 97 percent of scientists agreeing on anything is very rare. Scientists tend to be a very cautious.Are the other 3 percent Einsteins as Dale asserts?They are not.One of us has a former college housemate who is one of the 3 percent.He was awarded a Ph.D and first sold it to the tobacco industry to support the assertion that second hand smoke is harmless.Today he is paid by the fossil fuel industry to cast doubt on the human causality of climate change.
Al Poplawsky, a University of Idaho research specialist, is active in the Paradise Ridge Defense Coalition and the local Citizens’ Climate Lobby group.
Michael Jennings is an ecologist who, among other things, studies and advises on the relationships between climate and plants, animals, and ecosystems from local to global scales. He works with and interprets climate data and models that project climates we can expect in the future. He has worked for academic and federal institutions as well as conservation organizations. The opinions expressed here are his own.