TCS Daily

Heat Wave Hot Air

By Robert C. Balling - August 4, 2005 12:00 AM

In case you have been living in a cave, it has been hot this summer in the United States. Much of the nation has been in the midst of a substantial heat wave, and the global warming crusade is making the most of this opportunity.


Front page news stories carry headlines regarding deaths in Phoenix, record-breaking temperatures across the country, potential outbreaks of diseases, and all the rest.


But is this heat really somehow related to our burning fossil fuels, which thereby add greenhouse gases to the atmosphere and warm the planet?  According to dozens of news stories, the answer is yes. But consider the following facts:


(1)             The numerical global climate models predict that the Earth will warm given a continued build-up of greenhouse gases, most notably, the carbon dioxide gas coming from our burning of fossil fuels.  Indeed, temperature records from throughout the world show a warming of approximately 1F over the past century.  However, almost all of the warming has occurred during the winter months just as the climate models predict.  The models do not predict much change in the summer months in terms of temperature increase or some alteration of the atmospheric circulation.  Blaming heat waves on global warming is a stretch, at best.


(2)             We have seen heat waves throughout the climate history of the United States, and in fact, many of the most severe heat waves occurred early in the record.  Recall that Chicago and the Midwest had a crippling heat wave 10 years ago that also prompted cries of a link to global warming.  However, Tom Karl, one of Americas leading climatologists, conducted an extensive study of that event and published his results in the prestigious Bulletin of the American Meteorological Society.  He concluded "because of the impact of changes in instrumentation at primary National Weather Service stations, the potential affects of urbanization, and little trend of summer mean temperatures, it is unlikely that the macroscale climate of heat waves in the Midwest or in Chicago is changing in any significant matter."


(3)             Karl raises a point that cannot be lost in the heat wave shuffle.  Many cities in the United States have been growing for decades, and as they grow, the pavement and buildings create the well-known and well-understood urban heat island.  Many cities have seen an increase of 5 to 10F over the past century.  This urban-induced temperature increase has undoubtedly exacerbated summer heat waves there is no question whatsoever that human activities have increased temperature levels in cities!  However, that increase is entirely related to urbanization, not any build-up of greenhouse gases.


(4)             Robert Davis is a climatologist at the University of Virginia who has studied heat waves and human mortality.  He has published a series of articles on his research and finds that heat waves today are far less deadly than equivalent heat waves in the past.  In the journal Climate Research, Dr. Davis wrote These statistically significant reductions in hot-weather mortality rates suggest that the populace in cities that were weather-sensitive in the 1960s and 1970s have become less impacted by extreme conditions over time because of improved medical care, increased access to air conditioning, and biophysical and infrastructural adaptations. 


There is quite a lesson here. It is that, in the face of any changes, we adapt.


Life has existed on our planet for billions of years, and the climate over that time has changed from ice ages to periods much warmer than today. There is little doubt that as our cities grow, heat waves will be more severe in the urban areas. If global warming does in fact add to the problem, we will adapt to the new world, just as humans have done for millions of years.


But at the end of the day, we will still be left with those who insist heat waves are increasing in frequency, they are killing more people, and the mess is related to the build-up of greenhouse gases. They want action, and they want it now.


I ask: What action? And, more importantly, What will be the climate effect of your action? It is easy to take the moral high ground, claim heat waves are caused by global warming, and call for action now.  However, these actions can have unintended consequences while having no impact on climate.


Emissions of greenhouse gases are so large from China, India, Pakistan and many other developing countries that action in the United States will have a trivial impact on global climate. The United States could volunteer to disappear, and greenhouse gas concentrations would continue to rise given the enormous emissions from throughout the world.


Meanwhile, some actions could lessen our ability to adapt or at least some of us. If electricity prices are driven up, making air conditioning less affordable who will suffer the most? The poorest amongst us who can least afford higher prices, and who thereby would suffer more heat related deaths.


When the weather gets hot, people need to avoid heated rhetoric and engage in some cool thinking.


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