Former Vice President Al Gore has received this year's Nobel Peace Prize (shared with the United Nations' Intergovernmental Panel on Climate Change [IPCC]). Gore has been an indefatigable campaigner, warning against the real dangers posed by man-made global warming. In acknowledging the honor today, Gore added, "We face a true planetary emergency. The climate crisis is not a political issue, it is a moral and spiritual challenge to all of humanity. It is also our greatest opportunity to lift global consciousness to a higher level."

He's wrong to characterize global warming as a moral and spiritual problem. Man-made global warming is not some kind of environmental sin. It's just another commons problem that has emerged as human civilization continues to develop. Most environmental problems arise in what are called open-access commons. That is, people pollute air and rivers, overfish lakes and oceans, cut down rainforests, and so forth because no one owns those natural resources and therefore no one has an interest in protecting them.

The point is clearest in the case of tropical forests and fisheries. No one owns the forests or fisheries, so anyone may exploit them. No one has an incentive to leave any trees or fish behind because, if they do, someone else will harvest them and get the benefits for themselves. In other words, those who immediately benefit from exploiting the resource do not bear the long-run costs of its ultimate destruction. This mismatch between benefits and costs is a recipe for disaster. Similarly, no one owns the global atmosphere, so there is no incentive for anyone to protect it from various pollutants, including greenhouse gases that tend to raise average global temperatures.

Generally, humanity has solved environmental problems caused by open-access situations by either privatizing the relevant commons or regulating it. It will not surprise anyone that I generally favor privatization. That's because I believe that the overwhelming balance of the evidence shows that centralized top-down regulation tends to be costly, slow, often ineffective, and highly politicized. For example, fisheries which had previously been mismanaged by government agencies greatly improved after fishers were given property rights to fish in Iceland, New Zealand and off the coast of Alaska.

As a skeptic of government action, I had hoped that the scientific evidence would lead to the conclusion that global warming would not be much of a problem, so that humanity could avoid the messy and highly politicized process of deciding what to do about it. Although people of good will can still disagree about the scientific evidence for climate change, I now believe that Gore has got it basically right. The balance of the evidence shows that global warming could well be a significant problem over the course of this century. But a significant problem is not a "planetary emergency."

In fact, the latest scientific report from the IPCC release in February generally lowered the range of possible future temperature increases. The IPCC Summary offers six scenarios for possible temperature increases by the end of this century. In the low scenario, the likely range of temperature increase is between 1.1 degrees to 2.9 degrees Celsius (2 degrees to 5.2 degrees Fahrenheit) with a best estimate of 1.8 Celsius (3.2 degrees Fahrenheit). In the worst case scenario, average temperature rises to between 2.4 degrees and 6.4 degrees Celsius (4.3 degrees to 11.5 degrees Fahrenheit) with a best estimate of 4 degrees Celsius (7.2 degrees Fahrenheit). Except for the worst case scenario, the top temperatures are lower than the maximum projected by the IPCC Third Assessment Report in 2001.

In addition, the IPCC's new Summary continues the trend of lowering possible sea-level increases that it found in its previous scientific assessments. Again, depending on the scenario chosen, projected sea-level rise by 2100 could be between 18 centimeters to 59 centimeters (seven inches to 23 inches). The report notes that sea level rose about seven inches during the 20th century. No one much noticed the 20th century rise and an increasingly wealthy and more resilient 21st century will be able to handle the IPCC projected rise without too much difficulty.

How much will it cost to address man-made global warming? First, Yale economist William Nordhaus estimates that the Gore's proposals would reduce climate change damages by $12 trillion, but at a cost of nearly $34 trillion. Not a very good deal.

On the other hand, Nordhaus calculates that the optimal policy would impose a carbon tax of $34 per metric ton carbon in 2010, with the tax increases gradually reaching $42 per ton in 2015, $90 per ton in 2050, and $207 per ton of carbon in 2100. A $20 per metric ton carbon tax will raise coal prices by $10 per ton, which is about a 40 percent increase over the current price of $25 per ton. A $10 per ton carbon tax translates into a 4 cent per gallon increase in gasoline. A $300 per ton carbon tax would raise gasoline prices by $1.20 per gallon. Following this optimal trajectory would cost $2.2 trillion and reduce climate change damage by $5.2 trillion over the next century.

In his 1992 book, Earth in the Balance, Gore argued, "We must make the rescue of the environment the central organizing principle for civilization." Man-made global warming is an economic and technical problem of the sort that humanity has solved many times. For example, forests are expanding in rich countries because they have well-developed private property rights. Also in rich countries, regulations have helped once polluted rivers and lakes to become clean and have drastically cut air pollution. One of the keys to solving environmental problems is economic growth and wealth. Economists have identified various income thresholds at which various air and water pollutants begin to decline, with many indicators improving once GDP per capita in a country reaches around $8,000 per year. So keep in mind that anything that unduly retards economic growth also retards ultimate environmental clean-up, including global warming.

In any case, global warming is not the result of environmental sin; it is the result of human progress creating another commons problem. We do not need to "lift global consciousness"; we need to find a cheap, low-carbon source of energy. I have no doubt that man-made global warming is an economic and technical problem that an inventive humanity will solve over the course of the 21st century.

Still, congratulations are in order to Al Gore for being recognized by the Nobel committee for his persistence in trying to get humanity to pay attention to this new commons problem. But here's hoping that the solutions that are ultimately adopted don't end up creating even more problems.

Ronald Bailey is Reason's science correspondent. His most recent book, Liberation Biology: The Scientific and Moral Case for the Biotech Revolution, is available from Prometheus Books.