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February 25, 2013
Climate Change in Perspective
With the fanfare of released official weather records for 2012 comes the usual claims of "warmest this" and "historic extreme that." But, facts are stubborn things.
Global temperatures have leveled off over the past 15 years, even as carbon dioxide (CO2) concentrations have continued to rise. This is a measured fact that confounds strident climate-change predictions.
Why no corresponding rise of temperatures with increasing CO2? Because other gases, vapors, and chemical/physical effects are still operating in the atmosphere to influence climate. CO2 does not act in a vacuum.
Thus, as CO2 has increased dramatically over the previous decades, substantial global temperature increases have not materialized as we were assured they would by academic, government, and political scientists. This is in large part because of the overwhelming role water plays in regulating climate (for example, while CO2 is only at 0.04% by volume in the atmosphere, water vapor ranges from about 0 to 4%).
As far as climate statistics go, much perspective is needed. First of all, with respect to 2012 being touted as the warmest year on record for the contiguous U.S., note that the contiguous U.S. covers less than 2% of the earth's surface.
Next, the increase in globally-averaged temperature for 2012 of about 1oF is quite small by comparison with the mid-20th century baseline. I was an official weather observer early in my atmospheric-science career (starting more than 35 years ago). I know from personal experience that temperature measurements, which were typically made once per hour, were made by "eyeball averages" based on the meniscus level in the thermometer. So, in practice, measurements were made within about + or - 0.5oF accuracy. Notably, a 1oF increase is small indeed, taking measurement limitations into account.
Furthermore, the fact that the recent levels of the average global temperature have been a little bit higher than the average since reliable land-surface records have been continuously kept (since the mid- to late- 1800s) is also not remarkable. When good consistent records began, the globe was emerging from the latest of multiple ice ages. From approximately 1550 to 1850 the globe was experiencing what climatologist traditionally called the "Little Ice Age."
And, the claim that 2012 was a historic year for extreme weather... well, that is pure opinion, based on convenient myopia. Expanding the field of view, we see that, in the U.S., there were the Dust Bowl years in the 1930s, extended drought from 1949 to 1956, and massive historic New England storms in 1938, 1893, and 1821, to name a few memorable incidents. In addition, we can't be blind to the fact that 2012 had a near record low amount of tornadoes.
As for melting ice in the far north, while a substantial arctic storm contributed to the record minimum Arctic sea ice extent by blowing apart much of the ice, in the southern hemisphere, the Antarctic ice sheet has grown in recent years.
Climate anomalies, which can be selected to "prove" rising or falling thermometers, happen all over the globe. Picking changes that just match the current academic, governmental, and political "consensus" on climate change is not how authentic science is supposed to work.
But, it's no surprise that the consensus of scientists who are paid huge sums of money from government to find "the risk of human-induced climate change" (as the Intergovernmental Panel on Climate Change puts it) find that humans are responsible for climate change. Thousands of the rest of us atmospheric scientists, who have no stake in the outcome, find the hypothesis that humans are responsible for long-term, global climate change to be a stretch at best.
Perspective on the risk and benefit of CO2 emissions effect on the atmosphere is desperately needed. Regardless of the theoretical risk that CO2 from fossil-fuel burning for energy production is the driver of long-term, global climate change, the benefits of the use of such inexpensive fuel to alleviating miserable living conditions for about one billion people are clear. Yet, a trillion dollars may be spent over the next decade to reduce, eliminate, or sequester CO2 emissions that may yield only a fraction of a degree Celsius decrease in global temperatures (if you believe the climate-prediction models).
Sadly, such a spending spree will do next to nothing to address real tragedies like abject poverty in a world of plenty.
Anthony J. Sadar is a Certified Consulting Meteorologist specializing in air-pollution issues. His new book is In Global Warming We Trust: A Heretic's Guide to Climate Science (Telescope Books, 2012) www.inglobalwarmingwetrust.com.
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