In his column of Dec. 16, Ihor Kunasz urges us to avoid pseudo-science when discussing climate change. He then engages in pseudo-science himself by favoring only studies he likes and ignoring those that do not support his views.
Kunasz claims that tree rings show the earth is cooling in the past 10 years. Some tree ring studies show no change. Since precipitation, clouds, disease and increasing pollution all affect tree growth, tree rings are unreliable indicators of short-term temperature change.
He claims that satellite measurements show the earth has been cooling. Because of the disparity between satellite data and air temperature measurements at ocean levels, satellite data had to be re-evaluated. It now is interpreted as showing some temperature increase. Satellite data is greatly affected by the cooler upper atmosphere and has difficulty measuring ground- and ocean-level temperatures accurately.
He mentions that a small minority of studies have measurement flaws, disregarded relevant facts, or falsified data. That does not explain away the many properly performed studies that support global warming.
He claims the climate is controlled by sunspot activity and not by carbon dioxide. Sunspots? Sunspots cause a solar radiation fluctuation of one-tenth of 1 percent from minimum to maximum. Hardly significant compared to a 35 percent CO2 increase. Studies claiming a sunspot-climate temperature correlation have been shown to be deeply flawed and meaningless.
There are three facts central to this debate that Kunasz wants us to ignore:
1. Greenhouse gases such as carbon dioxide and methane trap heat in the atmosphere.
2. The 2008 carbon dioxide levels were 35 percent above the 1832 ice core levels.
3. Many events suggest the earth is warming. Glaciers are rapidly melting, some have disappeared, and polar sea-lanes are open to ship traffic for the first time in millennia. While snow is thickening a few glaciers, most are shrinking. This is happening at a rate of increase rarely seen in earth's history.
If glacial melting and polar icecap shrinkage are not caused by the build-up of greenhouse gases, then skeptics need to come up with a better explanation than denial. Sunspots and tree rings are trivial distractions from the central argument. Past rapid climate changes in earth's history resulted from large geologic and astronomical forces not present in the last 100 years.
Kunasz mentions that science is advanced by proof, not consensus. Actually, with a complicated subject like global warming, both are necessary. One cannot pick only the scientific studies one likes and ignore follow-on studies that debunk them. It takes the majority of scientists to wrest the argument away from those who wish to employ selective, superficial reasoning.
The human population, estimated at 6.8 billion, is now so large it affects global climate. The cartoon character Pogo was right: "We have met the enemy and he is us."
Dennis Evans lives in Oracle.