I had an argument about global warming the other night with a couple of friends. I achnowleged that the world was warming somewhat and some of that was due to man, but said that any rational estimate of future warming due to man’s efforts yielded forecasts far below the catastrophic levels espoused by Al Gore (and for which he will apparently win the Nobel Peace Prize on Friday). Their response, which I have found to be typical, was 1) it doesn’t matter how much the warming is, it is bad to change the earth at all and 2) we need to aggresively fight CO2 "just in case" there is some catastrophic tipping point lurking out there.
The problem is that the costs of abating CO2 to any levels that might make a difference are both enormous and certain (vs. global warming costs which may or may not be large and are uncertain). Since fossil fuel production is intrinsic to economic growth, at least at current technology levels, large cuts in fossil fuel productions mean large cuts in world economic growth. A reduction, for example, in economic growth by must 1 percentage point a year would reduce the size of the global economy by 2.5 times in a century. And a one percentage point reduction is surely less than the true effect of the levels of CO2 cuts that catastrophists are petitioning for.
In particular, what is seldom mentioned, is that CO2 cuts of the kind suggested in Kyoto-type protocols are likely to lock over a billion people into poverty, just at the time when they are beginning to get their first experiences with prosperity.
In 2007, human beings will consume roughly 15 terawatts of energy worldwide. That level of energy use will rise rapidly over the next 100 years due to population growth and increasing living standards, especially among the global poor. By the year 2100, humankind will need to produce and consume roughly 60 terawatts of energy if every human on earth is to reach the level of prosperity enjoyed today by the world’s wealthiest one billion people. Even if economies were to become much more efficient, the total terawatts needed to bring all of humankind out of poverty would still need to roughly double by 2050 and triple by century’s end.