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It is now evident that countries undergo various environmental transitions as they become wealthier. A World Bank analysis found that the first environmental transition -- the availability of clean drinking water--occurs when a country’s average annual per capita income reaches around $1300. Next, the concentrations of particulates and sulfur dioxide peak at per capita incomes of $3300 and $3700 respectively. Once these income thresholds are crossed, societies start to purchase increased environmental amenities such as clean water and air. BTW, some researchers believe that they may have identified another environmental transition point recently, it appears that when average per capita incomes reach about $16,000 per year, a country’s forests begin expanding. Over the last decade, forest expansion has picked up in Europe-- expanding at around 750,000 acres per year and in the U.S.by around 1 million acres per year.
So what about the more subtle and insidious pollution caused by ingesting synthetic chemicals? Rachel Carson’s 1962 book Silent Spring brought this issue forcefully forward. Carson declared that exposures to dangerous chemicals ... have entered the environment of everyone---even children as yet unborn. It is hardly surprising, therefore, that we are now aware of an alarming increase in malignant disease." By which she meant cancer. By 1970, Paul Ehrlich once again, painted a scenario in his Eco-Catastrophe article in which he envisioned a Department of Health, Education, and Welfare study finding in 1973, that because of contamination by synthetic chemicals, "Americans born since 1946 .. now had a life expectancy of only 49 years, and predicted that if current patterns continued this expectancy would reach 42 years by 1980, when it might level out." Last year, Worldwatch Institute founder Lester Brown, ominously noted, "Every human being harbors in his or her body about 500 synthetic chemicals that were non-existent before 1920." First, in reply to Brown, so what? Considering that American life expectancy has increased by 20 years, from an average of 56 years in 1920 to 71 years in 1970 to 76 years today, one might be tempted to argue that those synthetic chemicals are prolonging our lives.
There is a broad consensus that exposure to synthetic chemicals, even pesticides, does not seem to be a major health problem. In 1996, the National Research Council of the National Academy of Sciences, issued a comprehensive report called Carcinogens and Anti-Carcinogens in the Human Diet which concluded that levels of both synthetic and natural carcinogens are "so low that they are unlikely to pose an appreciable cancer risk." The National Cancer Institute reports that "increasing exposure to general environmental hazards seems unlikely to have had a major impact on the overall trends in cancer rates." The American Institute for Cancer Research concludes that "There is no convincing evidence that eating foods containing trace amounts of chemicals such as fertilizers, pesticides, herbicides and drugs used on farm animals changes cancer risk. Exposure to all manufactured chemicals in air, water, soil and food is believed to cause less than 1 percent of all cancers." In other words, Rachel Carson was wrong.
BTW, what is happening to cancer rates--both incidence and mortality are falling and have been for the last decade in the United States. Most of that decline can be traced to better health habits, most especially declines in cigarette smoking. What causes the bulk of cancer? According to Sir Richard Doll, head of the Clinical Trial Service & Epidemiological Studies Unit in Britain, smoking is associated with 30 percent of cancers, diet, especially eating lots of animals fats is associated with between 20 and 50 percent, infectins are responsible for between 10 and 20 percent and exposure to our own natural reproductive hormones accounts for about another 10 to 20 percent. Of course living longer means that you have a better chance of getting cancer.
GLOBAL WARMING--Now on to the pressing issue of global warming. Earlier this year the Intergovernmental Panel on Climate Change, the IPCC, issued its Third Assessment Report along with its famous Summary for Policymakers. That summary laid out scores of scenarios based on computer climate and econometric models and for the next 100 years in which global average temperatures were projected to rise by between 1.4 degrees centigrade and 5.8 degrees centigrade. Naturally, the press seized on the upper end of that temperature range and portrayed a world that would soon bake us all. President Bush asked a panel of climatologists under the auspices of the National Academy of Sciences to consider what is scientifically certain and what is scientifically uncertain about global warming.
The NAS report found that "Greenhouse gases are accumulating in Earth’s atmosphere as a result of human activities, causing surface air temperatures to rise and subsurface ocean temperatures to rise." No one argues w|Th any of the above claims, but they do not in themselves mean that the world is headed toward a climate disaster due to humanity’s activities.
Let’s briefly review the data on global temperature trends. Earth’s average temperature has apparently gone up by about 0.6 degrees Centigrade (C) plus/minus 0.2 C in the past century, concludes the IPCC. According to the highly accurate measurements taken from satellites of the entire troposphere (the bulk of the atmosphere from the surface to five miles up) the earth’s temperature since 1979 is increasing at a rate of 0.038 degrees C per decade. Weather balloon data from the same period show an increase of only 0.03 degrees C per decade. Taking the weather balloon data from 1958 to today, the average per-decade increase in temperature is 0.1 degrees C. Interestingly, weather balloon temperature data are essentially flat between 1958 and 1976. Between 1976 and 1978, global temperatures measured by weather balloons jumped dramatically, after which they essentially became flat again. No one knows why temperatures spiked in the mid-1970s, but such a spike is not consistent with human causation. Finally, the surface temperature measures on which those most concerned about global warming rely show an increase of 0.16 degrees per decade over the same period.
These actual data on temperature increases are interesting, since to reach an average global temperature increase of 3.0 degrees C by the end of the 21st century would imply that global average temperatures must increase by at least 0.3 degrees C per decade. (The U.N.’s Intergovernmental Panel on Climate Change projected an increase ranging from 1.4 to 5.8 degrees C by 2100.) That 0.3 degree per decade increase is evidently not happening. Those concerned about global warming claim that is because aerosols like soot and sulfur dioxide are shading the planet, causing a cooling countertrend. Perhaps, but even the National Research Council report admits, "The monitoring of aerosol properties has not been adequate to yield accurate knowledge of the aerosol climate influence."
What is the empirical data telling us? Climatologist John Christy says that "the data are telling us that the actual climate is not as sensitive to CO2 forcing as the computer models say it is."
But what about all those freakish weather events of late?
The IPCC itself in its third assessment report notes that there is no evidence that hurricanes, tornadoes, floods or droughts are getting worse or more violent than in the past, despite what you might see on the nightly news reports. There is some small evidence that the amount of rain has increasing slightly, and why not, a warmer world is a wetter world. What about the glaciers at Mt Kilimanjaro, in Peru and in Glacier National Park in the U.S. Aren’t they all melting away because of higher temperatures? Actually, in all those cases temperatures have not gone up--in both Peru and Glacier National Park average temperatures have been going down. By the way glaciers are growing in Norway.
Then what about sea level rise? Sea level rose by 6 inches in the 20th century and even the IPCC recently lowered its estimate for sea level rise in the 21st century to about 8 inches. Certainly not a catastrophe.
Isn’t the polar ice melting? Actually temperatures in Antarctica have been cooling for several decades and the sea ice area there has expanded. In the Arctic, picture is more complicated--at the highest latitudes temperatures have been declining slightly--some parts of Greenland are warming, but others are cooling and the net effect seems to be no great change in Greenland’s ice cover.
As climatologist John Christy, said, It appears that the climate models are too sensitive. What accounts for their inaccuracies? Most likely it’s because they get the clouds wrong. Clouds tend to act like shades during the daylight and like blankets at night--the result seems to be that whatever warming is occurring is being channeled into the winter nights. Daytime high temperatures do not appear to be going up much if at all. Vast uncertainties about aerosols, clouds, the ocean and fossil fuel consumption trends all together make the model predictions a very chancy tool with which to plan the energy future of humanity for the next century. And make no mistake, that’s what climate treaties like the Kyoto Protocol amount to.
The absurdity (not to say sheer arrogance) of that type of planning becomes clear when one imagines the same exercise taking place in 1900. The best scientific panel available in 1900--let’s say including Lord Kelvin, Albert Einstein, Madame Curie--would simply not have been able to plan for today’s 560 million automobiles and trucks, the ubiquitous electric lighting in hundreds of millions of houses and office buildings, fuel for thousands of jet planes, the electricity to run the world’s 160 million computers, hundreds of millions of refrigerators, central heating, air conditioners, and telephones. Virtually none of these devices on this nearly endless list had even been invented by 1900. Given the increasing rate of technological innovation, we undoubtedly stand in an even worse position for trying to plan the world’s energy needs of the year 2100.