Barring a last-minute intervention by the Supreme Court, the 2007 Nobel Peace Prize will be shared by Albert Gore Jr. Admittedly, Gore has been less of a menace to world peace than some previous laureates (think Henry Kissinger). But there is nothing particularly peaceable about Gore's rhetorical approach to climate policy. At his most pugnacious, Gore has depicted the fundamental trade-off as one between environmental responsibility and personal greed. Of course, as everyone over the age of 12 is perfectly aware, the real trade-off is between the quality of our own lives and the quality of our descendants'.
In other words, climate policy is almost entirely about you and me making sacrifices for the benefit of future generations. To contribute usefully to the debate, you've got to think hard about the appropriate level of sacrifice. That in turn requires you to think hard about roughly half a dozen underlying issues.
1. How much does human activity affect the climate? This is actually a whole menu of questions: What can we expect given the current level of carbon emissions? What if we cut those emissions by half? By two-thirds? And so on. These are questions for physical scientists, not economists or politicians.
2. How much harm (or good!) is likely to come from that climate change? This is partly a matter of physical science and partly a matter of economics. If the world temperature rises 3 degrees, agronomists try to predict the wheat yield in Oklahoma; economists try to predict when Oklahomans will turn to alternate ventures—and when it will become profitable to grow wheat in Alaska. Climatologists estimate what it takes to put New York underwater; economists estimate the cost of moving New York inland.
3. How much do we—or should we—care about future generations? Edmund Phelps, the 2006 Nobel laureate for economics, argued long ago that you (and I) should care exactly as much about a stranger born 1,000 years hence as we do about a stranger who's alive today. Phelps' view has been highly influential among economists, who now take it as more or less the default position. But even economists are sometimes wrong, and there are powerful arguments for "discounting" the welfare of future generations. First, many people (myself excluded, however) believe we should care more about our countrymen than about a bunch of foreigners—hence the sentiment for a border fence. If we are allowed to care less about people who happen to be born in the wrong country, why can't we care less about people who happen to be born in the wrong century? And second: Few of us feel morally bound to churn out as many children as we possibly can, which means we think nothing of denying future generations the gift of life. If it's OK to deny them their very lives, shouldn't it be OK to deny them a temperate climate?
There is a ton more to be said in response and counter-response, but in the end, you've got to take a stand. Does the next generation count 100 percent as much as our own, as Edmund Phelps demands? Or 99 percent? 95 percent? 90 percent? I'll show you later how much the answer matters.
4. How likely are those future generations to be around, anyway? If you think life on Earth will be destroyed by an asteroid in 200 years, it makes little sense to worry about the climate 300 years from now. (Of course, the issue is complicated by the fact that our climate policies change the survival odds.)