Everyone says the way not to begin a book is with an equation. But the book you are about to read is going to upset a lot of other common perceptions: facts about climate change, the nature of science and scientists, and the culture that surrounds what everyone seems to think is “the most important environmental issue of our time”: global warming. In January 2004, David King, science adviser to British Prime Minister Tony Blair, stated that climate change was a far worse threat to the world than terrorism. Months earlier, Sir John Houghton, head of the prestigious United Nations Intergovernmental Panel on Climate Change (IPCC), said precisely the same.
What this equation means is that human beings have the ability to change the temperature of the surface of the earth. The Energy Balance Equation is in fact simple, though it may look unfamiliar.
S is the amount of energy we receive from the sun. It's divided by four because the earth is a sphere and, as a whole, only one fourth receives the equivalent of direct illumination. Anyone older than thirty was taught in basic science that S is constant, as far as the earth's temperature is concerned. That was wrong. We know now that S varies, and it changes the surface temperature plus or minus about 1°C (1.8°F) on the order of millennia. Humans have no control over that.
α is the amount of energy that is reflected away by the earth. Fresh snow, for example, reflects 90 percent. Because most year-toyear climate variability is a result of changes in winter temperatures, rather than summer ones, warming up the planet a bit could have a big effect on standing snow cover. Subtracting the reflectivity from 1(1−α) yields the amount of energy that is absorbed by the earth. Human beings can change that amount in several ways: clearing a forest, building a city, farming, or burning anything with trace