There is a long history of environmentalism in American life. Yellowstone National Park was created in 1872. The Audubon Society, formed in 1905, was one of the earliest environmental groups. President Teddy Roosevelt (1901-1909) was probably the first "environmental president" with his conservationist policies. More modern environmental groups can be traced to events like the first Earth Day on April 22, 1970. Conservation was reborn, and concern about environmental issues became an increasingly important factor in assessing the quality of life.
Over the past fifteen years, global warming has become the central topic dominating the environmental debate. The concern is that industrialization has increased levels of "greenhouse gases" in the atmosphere, and the temperature of the Earth is rising. This is believed to be responsible for everything from melting polar ice caps to increased frequency of hurricanes to species extinction. Some environmentalists are calling for radical measures to reduce the production of greenhouse gases, most notably the Kyoto Protocol. So, are we on the brink of a human-induced disaster? Let's take a look at some facts.
Suppose the burning of fossil fuels is responsible for the increase in global warming. In that case, we should expect a noticeable rise in global warming correlated with the rapid growth of fossil fuel usage in the Twentieth Century. Have average temperatures risen over the last century? Yes. The average temperature has increased by about 2°C (less than 4°F.) But take a closer look at the average temperature history for the United States over the last century.
The real acceleration of greenhouse gas emissions is believed to have started after World War II. Notice the trend line from 1910 to 1940. It is the steepest temperature increase and was before the greenhouse gases really got flowing. The average temperature cooled during the increased gas emissions from 1940-1970! Since then, the average temperature has risen at a slightly slower rate than 1910-1930. What does this mean? Let's step back and take a longer view of what has been happening and add a couple more variables.
Using a variety of data, scientists can reconstruct average temperatures from previous eras with a reasonable degree of confidence. By analyzing data about the appearance of sunspots (which causes fluctuations in the heat from the Sun) and data such as variance in tree rings, scientists can get a fairly accurate measure of approximate temperatures in the past. The above chart shows a remarkable correspondence between solar output (dotted line) and the reconstructed temperature history (solid line) from 1600 into the Twentieth Century.
Temperatures began to be recorded using thermometers in the mid-18th Century. The thermometer readings (dashed line) correspond well to the other two measures until the last thirty years, when thermometer readings show a rapid rise contrary to the other measures. What happened here?
About three weeks ago, in late October, I woke up in the morning with my left eye swollen nearly shut and my right itching and watery. Despite taking antihistamines and trying to stay in climate-controlled environments, allergies got the best of me. We usually have had a freeze by November in Kansas City but not this year. Last week there was a forecast for a freeze. Sure enough, one came, but only in the burbs. I live about a mile from downtown, where the temperature is always slightly warmer. We had roses blooming in our backyard a few days ago in mid-November. Finally, we had snow flurries yesterday, and the freeze finally came.
My point is that it makes a difference where you place your thermometers. If you measured the average temperature at the spot where I live over the past 150 years and compared it with temperatures measured thirty miles to the west, you would see an increasing temperature change rate compared to the burbs. Some surface temperatures will be affected by human activity as cities expand and become industrialized. The reality is that the thermometers used for the temperature estimates are sparsely and unevenly dispersed across the planet. Fortunately, we have another option to compare to the thermometer readings. Satellite and weather balloon measurements give us another view. Satellites are particularly important because they give the planet more even and comprehensive coverage. What do these records tell us?
Satellite records are available back to 1979, and we learn that the average global temperature may have declined by 0.1°C between 1979 and 1997. Using more accurate and reliable temperature data, we get the following:
This chart shows a remarkable correspondence between solar irradiation (dotted line) and temperature changes (solid line.) Also notice the CO2 levels charted in the lower right-hand part of the graph and the lack of correspondence. Finally, let's step back and take a very broad look at the issue:
This data from the Sargasso Sea studies (the area of the Atlantic between the West Indies and the Azores) shows that we are emerging from a mini-ice age. Temperatures were much warmer in the Middle Ages than at present.
In short, global warming is a product of the natural ebb and flow of the Earth's ecology in relation to the Sun's activity. There is no human-induced catastrophe on the horizon. In fact, increased levels of carbon dioxide may be beneficial. Plants feed on carbon dioxide, and increased levels may contribute to plant growth and crop production for an expanding human population. Yes, there may be changes in sea levels and shifts in some weather patterns, but we could not stop them if we tried.
More intriguing than the climatology behind global warming is the sociology and economics behind it. I wrote about this two months ago in Publicly Funded Science, Global Warming, and Christian Responsibility. I will not recap that here. One website has a petition signed by nearly 18,000 scientists (as I recall) who reject the human culpability angle in the global warming dialog and reject the Kyoto Agreements. (Petition Project)
The real global warming danger is enacting legislation like the Kyoto Protocol by well-meaning, good-intentioned (and some not-so-well-meaning and good-intentioned) people. This type of measure risks driving the American economy into a major recession. This almost certainly would send the rest of the world into recession along with us. Those who will suffer the most are poor people around the world, who are seeing their quality of life improve through expanding global trade.
This is not to say that there might not be other harmful effects of the pollutants we put into the environment. Clean and safe environments are important matters. Conservation is a desirable aim. Finding less toxic and more renewable energy sources is important to society's long-term well-being. Finding effective ways of reducing waste is essential. However, "crying wolf" only harms future environmental efforts and makes people cynical about legitimate environmental concerns.
The good news is that we are reducing our levels of pollution.
Emissions of the six principal pollutants dropped 25% between 1970 and 2001. Aggregate emissions have leveled off in the past decade, but per capita emissions are in decline. We have much room for improvement but are hardly in an environmental crisis.
Conclusions
Global warming is not primarily, and probably not significantly, a human-influenced phenomenon. It may bring some changes to our lives, but radical changes to the world economy to stop the unstoppable will negatively impact the quality of life of millions of people worldwide, especially the poor. Air pollution is in decline, and quality of life with regard to the environment is stable if not improving in the US.
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