Early use of fire meant protection from harsh weather and predators, besides safer food. The evolution from fire to fossil fuels to nuclear energy is a path of improving human health and welfare arising from efficient and effective access to energy. One trade-off is that energy use by humans has always produced local environment change, for example, in the form of human artifacts on the landscape, or removal of trees from major areas for wood burning, or region-wide noxious air pollution from coal burning. On the other hand, ready availability of energy that produces wealth through the free market system provides ways to remediate or minimize environmental damage from energy use.
With widespread industrialization, human use of coal, oil and natural gas has become the centerpiece in an international debate about a global environmental impact, viz., global warming, its causes and its future course. Currently, fossil fuels provide around 84% of energy consumed in the United States, and roughly 80% of the energy produced worldwide. The clash between fossil fuel use that emits carbon dioxide to the air and the risk of deleterious global warming is embodied in the Kyoto Protocol and its attendant series of international negotiations focused on greenhouse gas emissions like carbon dioxide.
On scientific, economic and political grounds, the Kyoto agreement's mandates are flawed as a means to control the risk of global warming resulting fossil fuel burning while impelling world economic growth.
Projections of future energy use, applied to the most advanced computer simulations of climate, have yielded forecasts of future temperature increases from a continued increase of carbon dioxide concentration in the air. These have been compiled by the United Nations' Intergovernmental Panel on Climate Change (IPCC). The middle range forecast of their estimates of future warming, based on expected growth in fossil fuel use without any curbs, is for approximately a 1 degree Celsius increase between now and 2050. A climate simulation including the effect of the as yet unimplemented Kyoto Protocol, negotiated in 1997 and calling for a worldwide 5% cut in carbon dioxide emissions from 1990 levels, would reduce that increase to 0.94 C - an insignificant 0.06 C averted temperature increase.
To achieve the carbon dioxide emission cuts by 2012 as required under the Kyoto agreement, the United States would have to slash its projected energy use at that time by about 25%. Why, if the U.S. is required to lower its emissions so greatly, are the ultimate future temperature forecasts so pessimistic, in terms of avoided global warming? Because countries like China, India and Mexico are exempt from making emission cuts, and China alone will become the world's leading emitter of carbon dioxide in a few years.
Several economic studies indicate the cost of the carbon dioxide emission cuts to the U.S. would amount to $100 billion to $400 billion per year. Replacing the fossil fuels on which our economy relies has no simple answer. One major reason the Kyoto Protocol's mandates are so costly is that energy policy considerations have been constrained by political, cultural and social influences. For example, substantially expanding the number of nuclear power plants and reducing the number of coal plants would enable future energy growth needs and the carbon dioxide emission reductions to be met simultaneously. But no nuclear power plants have been built in the U.S. in over 20 years, owing to non-technical barriers. Further, renewable energy sources like wind and solar power have been discussed to distraction as potentially meeting energy growth and carbon dioxide emission cuts in the U.S. Both wind and solar power facilities are boutique energy resources because they are diluted and intermittent sources of energy. While they may be cost-effective in limited locales, they are unreliable for large-scale electricity generation. Also, often overlooked is the enormous environmental footprint that wind and solar farms would require. For example, to replace a conventional 1000 megawatt coal plant that spans tens of acres would require an isolated, uninhabited (and therefore pristine) area with correct meteorological conditions of roughly 400 square miles and over 2,000 wind turbines, plus the associated imprint of high-power transmission lines, roads, etc. Solar panel farms would produce environmental blight and degradation over a similarly sized landscape.
The Kyoto Protocol also has the potential to worsen international relations. The struggling economies of the world rely on the U.S. to maintain stability, provide aid and economic opportunity as a trading partner. While the developing nations are exempt from making carbon dioxide cuts, the severe economic impact on the U.S. overwhelmingly reduces both opportunity and hope for developing economies. Thus, the punishment to the U.S. economy as a result of severe energy restrictions will do little to lower the air's carbon dioxide concentration, but will devastate opportunities for developing economies.
The tension exists between an economic catastrophe occurring because of the implementation of the Kyoto Protocol and the likelihood of an environmental catastrophe resulting from a failure to act. The former is certain; the latter extremely speculative.
What are the scientific facts concerning human global warming effects?
The facts in scientific agreement are:
- As a result of human use of coal, oil and natural gas, the air's carbon dioxide (along with other human-produced greenhouse gases like methane) content is increasing.
- The greenhouse gases absorb infrared radiation, and, as a result, should retain some energy near the surface of the earth that would otherwise escape to space.
- Based on current ideas about how climate should work, the surface temperature should warm in response to the addition of the small amount of energy arising from a benchmark doubling of the air's carbon dioxide content.
Is that how the climate system operates?
The main greenhouse effect is natural and owes to water vapor and clouds (i.e., water droplets and ice crystals in clouds). The impacts of upper level moisture and clouds - the dominant greenhouse factors - are greatly uncertain. Hence, although sophisticated computer simulations of the impacts of increased carbon dioxide concentration in the air can and should be undertaken, the reliability of the results rests on validation of the simulations. However, uncertainties from calculating the effects of clouds and water vapor in simulations, besides other important factors like sea-ice changes, are up to ten times larger than the effect of the variable being tracked, i.e., the effect of doubling the carbon dioxide in the air's carbon dioxide level.
Technological breakthroughs in climate science can help put the matter of human-made global warming in better perspective.
One key question that deserves an answer at the start of the debate is: What has been the response of the climate thus far to the small amount of energy added by humans from increased carbon dioxide in the air? To prove the reliability of their future forecasts, computer simulations need verification by how they have reproduced past temperature change. Two temperature major records of importance are collected near the surface and in the lower atmosphere.
In the 20th century the global average surface temperature rose about 0.5 C. At first glance the warming seems attributable to human fossil fuel use, which increased sharply in the 20th century. But a closer look at the 20th century surface temperature record shows three distinct trends:
First, a strong warming trend of about 0.5 C began in the late 19th century and peaked around 1940. Then, oddly, there was a cooling trend from 1940 until the late 1970s. And the third phase of the surface record shows a modest warming trend from the late 1970s to the present. Yet about 80% of the carbon dioxide from human activities was added to the air after 1940, and so the air's increased carbon dioxide content cannot account for the first substantial warming trend, which appeared before 1940. Then, as the air's carbon dioxide content increased most rapidly, temperatures dropped for nearly 40 years, before rising then again since the late 1970s. The early 20th century warming trend had to be largely natural. Human effects at most amount to about 0.1 C per decade - the maximum amount of the warming trend seen since the late 1970s. How does the observed surface-warming trend in recent decades - assuming it is all anthropogenic - compare to the results of the computer simulations?
Climate simulations predict that a smooth, linear rise of at least twice the observed trend should already be occurring, and will continue through the next century. If the warming trend has been observed to be at most 0.1 C per decade from human activities, then over ten decades the forecasts are exaggerating the future warming, which should be adjusted downward to at most 1 C warming trend by 2100. This amount of warming would be very similar to natural variability, with which man has coped for thousands of years. That warmth may return the climate to conditions seen in the early centuries of the second millennium, from about 800 to 1200 C.E., when widespread warming is indicated by numerous proxies of climate, such as glaciers, pollen deposits, boreholes, ice cores, coral, tree growth plus sea and lake floor sediments. The Medieval Climate Optimum saw a human response in the settling of Greenland, Iceland, travel by the Vikings to Newfoundland, higher crop yields and generally rising life spans.
Second, and more important, the recent trend in surface warming may not be primarily attributable to human action at all. U.S. leadership in new space instruments and funding -- about $18 billion in the last decade - in global research has yielded critical information indicating an even lesser human effect on global climate change than the climate simulations forecast.
The simulations of climate predict that a readily detectable warming both of the surface and of the lowest layer of air above the surface - the lower troposphere - to a few kilometers altitude must occur with the presence of increased atmospheric carbon dioxide concentration. Measurements made with NASA's microwave sounder units aboard satellites, and validated independently by balloon radiosondes, show an absence of the forecast human-made global warming trend. In addition to being validated by a separate instrument, the satellite record of the temperature of the lower troposphere essentially covers the globe, while those at the surface cover about one-fifth of the planet's surface. The troposphere temperature does display large, natural variations, for example, during the strong El Niño warming pulse of 1997-98, but no meaningful human warming trend is seen over the 21-year span of the record.
One proposed explanation for the lack of a significant human-made global warming trend in the lower troposphere is that human induced global warming is present but masked because soot from sulfur dioxide and other human-made aerosols simultaneously cool the atmosphere, leaving little warming trend. But that idea of a widespread aerosol shading effect fails the test by the scientific method, because the Southern Hemisphere, which is relatively free of aerosols, shows no long-term warming trend at all. That fact contradicts the models' forecasts of significant human-made global warming and the hypothesis that aerosol pollutants are masking a significant human-made warming trend.
The radiosonde record obtained from balloon-borne instruments not only confirms but also extends the results from the satellites. Although the radiosonde record lacks the dense spatial coverage of measurements made by satellites, the two sets of measurements agree very well when they overlap. The longer radiosonde record finds no trend of warming attributable to human activities going back four decades. There is a sharp warming in 1976-77 - a warming known as the Great Pacific Climate Shift of 1976-77. The shift owes to a natural, periodic shift in the Pacific, called the Pacific Decadal Oscillation, which is so significant that surface temperatures averaged world-wide appear to be affected. Furthermore, the Pacific seems to have shifted back, perhaps in 1998 - 99, to its pre-1976 phase, which should produce cooler temperatures, especially in Alaska and in the world-wide average.
The most reliable data exhibit no evidence for human-made catastrophic warming. When compared to the measurements, the output from computer simulations all forecast exaggerated warming trends for the last four decades, compared to the sensitive lower tropospheric response. The forecasts exaggerate to some degree the warming at the surface, and decidedly in the lower troposphere. Because the models have exaggerated warming trends for the past several decades, the computer results presumably also exaggerate their forecasts of warming for the next century.
The exaggerated trends are not surprising. The computer simulations of climate must track over 5 million parameters relevant to the climate system. To simulate climate change for a period of several decades is a computational task involving 10,000,000,000,000,000,000 degrees of freedom. And the simulations require accurate information on the two major, natural greenhouse gas effects - water vapor and clouds, which are uncertain at present.
Finally, in looking for natural factors influencing the climate, one area of new research is the effect of a changing sun. The pattern of 20th century temperature change shows a strong correlation to the changing energy output of the sun. Although the causes of the changing sun's particle, magnetic and energy outputs are uncertain, as are the responses of the climate to the sun's various changes, the correlation is pronounced. It explains especially well the early 20th century temperature rise, which cannot have much human contribution.
Based on the best temperature measurements of the last several decades, the actual response of the climate to the increased carbon dioxide content of the air has shown an insignificant man-made global warming trend. The magnitude of expected human change is especially constrained by the lack of observed global warming trends in the lower troposphere.
This is good news. It means that the human global warming effect is small and would be slow to develop, affording an opportunity to continue and improve observations and computer simulations of climate. That will serve to better define the magnitude of human-made warming, and allow development of an effective, and cost-effective response.
Three things can be said about the risk of perilous global warming from human energy use:
No catastrophic human-made global warming effects can be found in the best measurements of climate. Furthermore, many of the alleged impacts have not appeared. For example, hurricane frequency has not increased in the United States over the last half of the 20th century; key infectious diseases such as malaria have been eradicated in the United States by the health, living and technological advances made in the last century.
Energy use helped accomplish this last advance as it has also fed vast numbers of people while elevating them from poverty. The longevity, health, welfare and productivity of humans have improved with the use of fossil fuels for energy, and the resulting human wealth has helped produce environmental improvements beneficial to health as well.
Carbon dioxide, the primary greenhouse gas produced by burning fossil fuels, is not a toxic pollutant. It is essential to life on earth. Plants, including crops, have flourished owing to the aerial fertilization effect of increased carbon dioxide in the air. Agricultural experts estimate a 10% increase in crop growth in recent decades owing to the heightened concentration of carbon dioxide in the air.
The best science offers little justification for the rapid cuts in carbon dioxide mandated by the Kyoto Protocol. Furthermore, the economic consequences come with considerable human and environmental risk, at the cost of no significant climatic improvement in terms of avoided temperature rise by the middle of the 21st century, according to the climate simulations.
Given the lack of benefits for the Kyoto Protocol, what then is guiding its international momentum? One strong factor is the philosophy of the Precautionary Principle in environmental regulation. The Precautionary Principle disallows an action that might harm the environment, until the action is certain to be environmentally harmless. That philosophy is antithetical to science in practice, because it sets an impossible goal in proving harmlessness with certainty.
In the case of global warming, the Precautionary Principle is more extremely interpreted to mean that any hypothetical risk to the earth requires immediate action to eliminate the possibility of the risk. Hence, the Precautionary Principle insists on sharply curtailing fossil fuel use, and essentially, energy use, despite the harm to human health, welfare and the environment.
Thus, despite the lack of evidence for catastrophic global warming and its calamities, the Precautionary Principle urges adoption of a policy of "doing something," which is promoted as needed "insurance" against the possible risk to the earth. That portrayal of insurance as a prudent hedge is wrong on two counts, notwithstanding the scientific lack of detection of significant human-made warming. First, the actuarial notion of insurance is that of a carefully calculated premium paid against a risk known reasonably well in outcome and probability of outcome. In the case of human-made global environmental effects, the risk, premium and outcomes cannot be well defined. Yet risk calculations have been attempted by averaging the ensemble of results from various computer simulations, none of which yield reliable results.
More important is the second element of the flawed insurance analogy: the notion that buying the Kyoto Protocol is effective insurance - as stated above, the averted temperature rise resulting from mandated emission cuts will be inconsequential in terms of natural climate variability. Additionally, the underlying basis for present international negotiations is the Rio Treaty of 1992, which specifically states that concentrations of greenhouse gases in the atmosphere, not emissions, be stabilized. In order to stabilize the air's concentration of greenhouse gases, emissions would have to be cut some 60 - 80 %, a much steeper cut than the Kyoto agreement mandates.
For the next several decades, fossil fuels are key to improving the human condition. The scientific facts show the liberation of fossil fuels from their geologic reservoirs and mankind's use of them provide many economic, health and environmental benefits, whereas the environmental catastrophes forecast from their use by critics have yet to be demonstrated.
Editor's note: This article is adapted from a speech presented at Hillsdale College.
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