No Free Lunch: Economics for a Fallen World: Third Edition, Revised

Chapter Six: Applications in Markets 143 The debate over tobacco is a similar argument. If you are in your own house, in most cases no one has a right to tell you not to smoke. In my house, I will ask you not to smoke and you will agree or leave. But what about public property? Who owns that air (see the example below for one implication of poorly defined property rights of air)? What about privately owned restaurants that are open to the public? Can they decide to allow smokers, or alternatively ban them? When property rights are clearly defined with the appropriate legal safeguards, social conflict over pollution is reduced. WHAT IF NO ONE OWNS THE AIR? “‘Asian Brown Cloud’ Threatens U.S.” by Sid Perkins on 25 May 2012, 8:00 AM China and India are some of the world’s top polluters, with countless cars, factories, and households belching more than 2 million metric tons of carbon soot and other dark pollutants into the air every year. These pollutants aren’t just bad news for the countries themselves. A new study reveals that they can affect climate thousands of kilometers away, warming the United States by up to 0.4°C by 2024, while cooling other countries. Some forms of pollution—especially light-colored aerosols such as sulfates that spew from power plants and volcanoes—scatter light back into space, cooling Earth. But dark aerosols, such as soot from diesel engines and power plants, absorb more sunlight than they scatter, gaining heat and warming the air around them. Rapidly developing countries, especially China, India, and those in southeastern Asia, are prolific sources of such aerosols. Over the past few decades, the pall hanging over the region has come to be known as “the Asian brown cloud.” Previous studies have shown that even though layers of air polluted with carbon aerosols become substantially warmer, the cloud slightly cools temperatures at ground level, by some estimates reducing the amount of sunlight reaching the surface by between 10% and 15%. The brown cloud also weakens winds during the Asian summer monsoon and changes the timing and location of monsoon rainfall. The cloud has dramatically thickened in recent decades, with some studies showing that dark aerosol emissions from China alone doubled between 2000 and 2006. The sixfold and 10-fold increases in dark aerosol emissions would cause global average temperatures at ground level to rise 0.1°C by 2024, the researchers report in a forthcoming issue of Geophysical Research Letters . But possibly more important, the thickening brown cloud would trigger significant changes in long-term weather patterns that would affect areas thousands of kilometers away . The effect would be somewhat like a human-made El Niño, the climate phenomenon in which sea-surface warming in the tropical Pacific alters temperature and precipitation in the United States and elsewhere. Although scientists have long studied the effects of pollutants on cloud formation and other small-scale phenomena, determining their effects on climate in distant regions is a relatively new field, says Chien Wang, an atmospheric scientist at the Massachusetts Institute of Technology in Cambridge, who wasn’t involved in the research. The new findings “are not surprising at all,” he notes. However, he adds, the team’s new study “is a highly idealized experiment,” so the results are probably more accurate in terms of capturing the overall pattern of changes than they are at estimating the precise amount of warming or cooling in a particular locale.