January/February 2007

The Global Warming/Climate Change Scenario

By George W. Zobrist

Global warming, also known as climate change in some circles, is a politically charged topic. While it is true that the temperature on earth has increased over the past 100 years, it is still uncertain to what extent human behavior has contributed to the trend. One can find convincing arguments on both sides of the debate. A casual Web search will yield a wealth of information on this topic. Information on this topic can also be found on the IEEE Web site.

Global warming is the average temperature increase of the earth, which, in turn, can cause the earth's climate to change. Climate Change is the long-term changing of weather patterns, either induced by human mismanagement of the environment, or by natural effects, such as sun spots and volcanic activity. There is also the Greenhouse Effect which causes the earth to warm by trapping heat in the atmosphere. Ozone layer diminishment allows harmful radiation to reach the earth's surface, which can become trapped in the atmosphere, raising the temperature on the Earth's surface and lower atmosphere.

Well-known climatologist Michael Mann's "hockey stick" graph of the temperature record of the past 1,000 years has generated much of the recent interest in global warming. Featured prominently in Al Gore's An Inconvenient Truth, the graph illustrates an abnormal increase in global temperatures over the past 100 years or so, coinciding with the industrial era. Some statisticians have corrected Mann's results for various formulation errors and the effect was diminished. But the graph remains startling and warrants further discussion and analysis.

The buildup of some greenhouse gases occurs naturally. But carbon dioxide buildup — the primary suspect in the latest warming trends — is accelerated by the burning of fossil fuels, land clearing and agriculture. The debate is over what percentage occurs naturally and what percentage is caused by humans — and whether the human contribution is increasing disproportionately and changing the Earth's climate patterns. If so, how do we measure it? And, ultimately, what can we do about it?

Measuring Global Warming

When discussing climate change, it is important to note that climate models are imperfect and uncertainties in formulation exist. Some of models predict strong regional changes, rather than worldwide. The National Academy of Science points out the difficulties of predicting global warming trends on time scales of decades and centuries. They question the ability to model from data obtained for temperature estimates going back thousands of years using ice/tree data with a degree of confidence. Limits on the calculation size exist, and interpreting the answers can be as complex as trying to interpret nature itself. Temperature changes have indeed been observed, but scientists remain uncertain as to how much can be attributed to nature and how much can be attributed to humans.

Biochemist Ed Wheeler points out that there have been warm/cold events over the millennium and mankind has adapted [Ecoworld, 25 April 2006]. He reasons that computer models are only as good as the assumptions programmers put into the simulations; we can't predict weather over a few days reliably, so why do we think it can be predicted over a 100 years?

The Environmental Protection Agency (EPA) has compiled numerous articles on this climate change. According to the EPA, causes of a natural change in climate include: Earth orbit variations, changes in the sun's intensity and volcanic eruptions. These events trigger other changes such as greenhouse gas concentration and the alteration of ocean currents. Human civilization arose during a period of relative climate stability (the last 2,000 years have been relatively stable), which leads to a discussion over whether we have passed over the 'warm" limit of the past in the 20th century.

Duke University researchers have suggested that only 10 to 30 percent of global warming is due to solar activity, but there is dissent to this research.

The user encyclopedia Wikipedia provides excellent descriptions of the Global Warming phenomena. According to Wikipedia, current prevailing scientific opinion holds that there is a long-term warming trend, and that "most of the warming observed over the last 50 years is attributable to human activities." [http://en.wikipedia.org/wiki/Global_warming]. But there is a vocal minority which disagrees with this point of view, too.

Skeptics of global warming theory share a wide array of opinions, but many feel that global warming theorists are predicting doom-and-gloom worst-case scenarios involving cataclysmic floods and ice ages, in essence preying on people's fears to make their case. Skeptics argue that there have been broad temperature fluctuations in the past, before human interaction with the environment, and that solar and volcanic activities were — and are still — the major sources of temperature change. Another of the skeptics' arguments is that the majority of the temperature measurements have been taken in urban areas (also know as 'urban heat islands").

The Upside of Global Warming?

According to global warming skeptic Bjorn Lomberg, the Earth's warming could have potential benefits: the Northern regions would be able to have a longer season for raising crops. Also, one can't be sure that the warming effect will not be moderate, rather than severe, as some models suggest.

Another, somewhat cynical, view is that the majority of problems stemming from global warming would affect coastal areas, which tend to be hazard-prone zones even without global warming concerns.

It is interesting to note that without the historic global warming trends, the earth's average temperature would be around 0 degrees Fahrenheit, rather than the present 57 degrees Fahrenheit.

The Cost of Global Warming

Lomberg's 2 November 2006 editorial in the Wall Street Journal [www.opinionjournal.com/extra/?id=110009182] posed the question: Is it better to spend money on known urgent problems in third world countries (and, first world countries), rather than the huge sums required to address global warming (which in some quarters is still speculative)? Lomberg's message came in response to a startling report by British economist and academic Nicholas Stern, which warned that global warming could eliminate up to 20 percent of world economic output forever if left unchecked.

According to one opinion in The Economist, the cost of addressing climate change is unknown. The piece suggests that the low end of change would probably make only certain areas uncomfortable [www.economist.com].

But, if the risk is deemed 'big" enough, then, much like governments have standing armies in times of peace, and individuals have flood/household insurance, then it is probably wise to 'purchase" some Global Warming insurance by spending a small portion of the world's income to address this problem. The main problem is 'political" — each generation puts off addressing the problem, leaving it to the next generation to deal with the consequences.

Mitigation of global warming can result from: reduction in energy use, replacing carbon-based energy with alternate energy, carbon capture/storage, carbon sequestration, and engineering to cool the earth down (planetary).

The Economist suggests that to address the problem, we first need to put a a price on emitting greenhouse gases, either a carbon tax or a cap/trade tax which would be used for spending on alternative fuels and on carbon sequestration.

Engineering a Solution?

According to some, we can engineer ways to cool the planet. Certainly engineers play a critical role in designing technologies that are energy efficient, and friendly to the environment. And President Bush, in his annual State of the Union address, renewed his call for advancing renewable alternative energy sources, and the need to wean the nation's dependence on fossil fuels by 20 percent over the next 10 years — through technology. But there are also more novel, "out-of-the-box" approaches. Arizona astrologer Roger Angel has proposed deploying a giant sunshield in orbit around the Earth to offset global warming [USA Today]. His "sun shade" would involve launching trillions of ultra-thin, two-foot-diameter shades into an orbit aligned with the sun.

References

• Businessweek.com (8/16/04)

• USA Today (11/9/06)

• NAS.edu; Economist (9/9/06)

• Mann (Nature 1998)

• Roger Angel (Proc of National Academy of Science 11/06)

• Ecoworld.com; EPA.gov

• Wikipedia.org

• Dukenews.duke.edu/2005

• Wall Street Journal 11/2/06

• Nicholas Stern Review of Economics of Climate Change (WSJ – 11/2/06)

• Bjorn Lomorg Article (WSJ – 11/2/06)

• ncdc.noaa.gov

• whrc.org

• akdart.com

Dr. George W. Zobrist is professor emeritus at the University of Missouri-Rolla, Department of Computer Science, IEEE-USA's Member Activities editor, and former editor of IEEE Potentials. Comments may be submitted to todaysengineer@ieee.org.