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Global Warming: Is It Really a Crisis?

John McCain, Barack Obama, and Hillary Clinton all promise massive new regulations that will cost trillions of dollars to combat global warming. McCain says that it will be his first task if he wins the presidency. After consulting with Al Gore, Obama feels the problem is so imminent that it is not even really possible to wait until he becomes president.

Ironically, this political unanimity is occurring as global temperatures have been cooling dramatically over the last decade.

Global temperatures have now largely eliminated most of the one degree Celsius warming that had previously occurred over the last 100 years. Hundreds of climate scientists have warned that there is not significant man-made global warming.

A conference in New York on Monday and Tuesday this week will bring 100 scientists together to warn that the there is no man-made global warming crisis.

Yet, we just keep on piling on more and more regulations without asking hard questions about whether they are justified.

New mileage per gallon regulations were signed into law last year that will mandate cars get 35 MPG. The rules will make us poorer, forcing people to buy products that aren’t otherwise the best suited for them. More people will die because lighter cars are less safe, but we are told this is all worth it largely because of global warming.

But much of what gets passed is arbitrary. Was there anything scientific about picking 35 MPG instead of, say, 30 MPG other than the desire to do more? And how do these regulations fit in with all the gasoline taxes we have that are already reducing gas use?

To see if all this makes any sense there are really four questions that all have to be answered "yes."

1) Are global temperatures rising? Surely, they were rising from the late 1970s to 1998, but "there has been no net global warming since 1998." Indeed, the more recent numbers show that there is now evidence of significant cooling.

2) But supposing that the answer to the first question is "yes," is mankind responsible for a significant and noticeable portion of an increase in temperatures? Mankind is responsible for just a fraction of one percent of the effect from greenhouse gases, and greenhouse gases are not responsible for most of what causes warming (e.g., the Sun).

Over 100 leading climate scientists from around the world signed a letter in December stating: "significant new peer-reviewed research has cast even more doubt on the hypothesis of dangerous human-caused global warming."

In December a list was also released of another 400 scientists who questioned the general notion of significant manmade global warming.

3) If the answer to both preceding questions is "yes," is an increase temperature changes "bad"? That answer is hardly obvious.

Even the UN’s original draft stated that an increase in temperature of up to two degrees Celsius would be good for many regions of the globe. Higher temperatures could increase ocean levels by between seven inches and two feet over the next 100 years.

Although some blame global warming for seemingly everything, according to others higher temperatures will increase the amount of land that we can use to grow food, it will improve people's health, and increase biological diversity.

4) Finally, let's assume that the answer to all three previous questions is "yes." Does that mean we need more regulations and taxes? No, that is still not clear.

If we believe that man-made global warming is “bad,” we still don’t want to eliminate all carbon emissions. Having no cars, no air conditioning, or no electricity would presumably be much worse than anything people are claiming from global warming.

You want to pick a tax that just discourages carbon emissions to the point where the cost of global warming is greater than that of cutting emissions.

Too little of a tax can be “bad” because we would produce greenhouse gases when their costs were greater than the benefits. But too much of a tax also makes us poorer because we won’t be getting the benefits from cars or electricity even when the benefits exceed the costs that they would produce from global warming.

What is often ignored in the debate over global warming is that we already have very substantial taxes on gasoline, averaging 46 cents per gallon in the US. Even if one believes that gasoline use should be restricted to reduce carbon dioxide emissions, the question is whether our taxes are already restricting use "too much" or "not enough.” But simply saying that carbon dioxide emissions are bad isn’t enough.

In fact, William Nordhaus, an economics professor at Yale and former member of President Carter’s Council of Economic Advisors, puts the “right” level of gasoline taxes at around 10 cents a gallon today, reaching 16 cents per gallon in 2015. Nordhaus’ analysis assumes that the answers to the first three questions are “yes.” If anything, while gasoline taxes are partially used for such things as building roads, it seems quite plausible that, even accepting Nordhaus’ assumptions, current gasoline taxes are much too high to deal with the harm from global warming.

However good the intentions, the debate over global warming is much more complicated than simply saying that the world is getting warmer. It is too bad that these questions won’t be getting a real debate this election. The irony is that those who sell themselves as being so caring aren't careful enough to investigate the impact of their regulations.

John Lott is the author of Freedomnomics and a senior research scientist at the University of Maryland.