The Obama administration has issued the newest "sky-is-falling" climate change report, suggesting that global warming and the "climate disruption" from unusual weather events call for "the need to take urgent action." The proposed actions don't include unpopular and effective measures like gasoline taxes.
The new report describes recent US floods, droughts, severe weather, and heat waves, all of which are not unprecedented compared to decades past. As to the frequency of extreme weather events, we have a recent TV interview by Warren Buffett, chief executive officer of Berkshire Hathaway, one of world's largest casualty insurers. Buffett noted on CNBC, "While the question of climate change deserves lots of attention, it has no effect on the casualty insurance prices we're charging this year versus 5 years ago. And I don't think it'll have an effect on what we're charging 3-5 years from now. Hurricanes in recent years have been all profit. Future catastrophe forecasts appear to be no different than in the past."
Tree ring and other research show the western US having severe droughts lasting for a decade and more during the past few thousand years. This is the eighth year with no Force 3 or stronger hurricane reaching the US mainland, and 2013 was the quietest Atlantic hurricane season in a century. Force 1 Sandy did major damage because we have built so much stuff on flood plains. The Great New England Hurricane of 1938 was the most destructive storm to strike the region in the 20th century, killing 700 people. And US tornado intensity has declined in recent years.
The earth's surface temperature is the result of the exchange of radiative fluxes involving the earth's surface, its atmosphere, and free space on the basis of their average thermal structure. We are warmed by solar radiation, half of which is reflected away or absorbed in the atmosphere before reaching the earth's surface. The earth's temperature is balanced by emissions of infrared radiant energy that are lost to colder free space from both the earth's surface and its atmosphere.
The greenhouse effect notes that some of the earth's infrared output is captured by certain atmosphere gases, especially water vapor, which trap this outgoing radiation. This is supposed to provide a kind of blanket, sending heat from the cold upper air to the warmer surface below. This violates the second law of thermodynamics which tells us that heat moves toward cold, like outer space, making the greenhouse effect unlikely.
During recent millennia, global temperatures have fluctuated naturally, without regard to carbon dioxide emissions from the burning of fossil fuels. The Roman Empire period was relatively warm followed by a few hundred years of colder temperatures when crops failed and misery prevailed. We call that colder time the Dark Ages. Then warming resumed into the Medieval Warm Period, when the Vikings settled Greenland, growing grain and raising wine grapes and great cathedrals like Chartres were built in Europe. Beginning about AD 1200, the earth cooled again into the long Little Ice Age. In the 17th Century the Thames froze solid, supporting the annual Frost Fair when thousands of people, horses and carts, and vendor booths filled the frozen surface. After 1800 the earth started a slow warming period which continues to the present.
It's the absorption and emissions of water, atmospheric water vapor and condensed cloud particles, and the heat content of oceans that have a major role on our weather events and surface temperatures. Trace gases like carbon dioxide have minimum effect.
If we are to experience a climate change catastrophe, it will likely be to our economy from ill-conceived government programs that send energy costs soaring.
Rolf E. Westgard
Osher Lifelong Learning Institute
University of Minnesota
St. Paul
