Somewhere in between the raving Al Gores of the world and the equally raving "No, global warming is totally impossible!" folks is a sparsely-populated region of sensible opinion. It seems like Freeman Dyson is somewhere in this region, but very few others are -- at least, very few voices who can actually get heard in the media.
The basic problem is this: it's pretty clear that if we add extra CO2 to the atmosphere, the planet will get warmer. And it's also clear that if the planet gets warmer, then there will be bad effects. Thus we really should be able to come up with some sort of dollars-per-ton value (let's call it K) for exactly how much harm is caused by CO2 emissions and work from there, perhaps applying some sort of tax to properly take into account the externalities of CO2 emissions.
The problem is that sensible estimates for the value of K vary by many orders of magnitude, and values which are not sensible but are nonetheless widely implicitly accepted vary by an additional bunch of orders of magnitude on either end. First, we have the uncertainty of exactly how much CO2 causes exactly how much warming. Secondly, we have the uncertainty of how much warming causes how much harm -- again, several orders of magnitude in the sensible estimates.
And that's without getting into the additional problems of expressing total worldwide harm in dollars (if we make Siberia into great farmland but drown Tonga is that a net loss or a net gain?) which I'm not gonna even talk about.
Now, if we could all accept that there's a genuine question to be answered about how big K is, and that there are still enormous error bars involved in determining this quantity, then we might be able to get down to having the sensible and important discussion which we as a species really need to be having at this point in history.
Unfortunately, the majority of the voices we hear nowadays are coming from the extremes -- either the Al Gores and Ted Turners of the world who want us to believe that K is huge, or the folks who want us to believe that K is zero. (Actually I'm not sure that the K = 0 folks really exist in large numbers, but they're a convenient strawman for those who believe K is huge.)
I don't know what the solution is, but as usual it would help if the media would hire a few more people who actually had some clue about the way science works.
The basic problem is this: it's pretty clear that if we add extra CO2 to the atmosphere, the planet will get warmer. And it's also clear that if the planet gets warmer, then there will be bad effects. Thus we really should be able to come up with some sort of dollars-per-ton value (let's call it K) for exactly how much harm is caused by CO2 emissions and work from there, perhaps applying some sort of tax to properly take into account the externalities of CO2 emissions.
The problem is that sensible estimates for the value of K vary by many orders of magnitude, and values which are not sensible but are nonetheless widely implicitly accepted vary by an additional bunch of orders of magnitude on either end. First, we have the uncertainty of exactly how much CO2 causes exactly how much warming. Secondly, we have the uncertainty of how much warming causes how much harm -- again, several orders of magnitude in the sensible estimates.
And that's without getting into the additional problems of expressing total worldwide harm in dollars (if we make Siberia into great farmland but drown Tonga is that a net loss or a net gain?) which I'm not gonna even talk about.
Now, if we could all accept that there's a genuine question to be answered about how big K is, and that there are still enormous error bars involved in determining this quantity, then we might be able to get down to having the sensible and important discussion which we as a species really need to be having at this point in history.
Unfortunately, the majority of the voices we hear nowadays are coming from the extremes -- either the Al Gores and Ted Turners of the world who want us to believe that K is huge, or the folks who want us to believe that K is zero. (Actually I'm not sure that the K = 0 folks really exist in large numbers, but they're a convenient strawman for those who believe K is huge.)
I don't know what the solution is, but as usual it would help if the media would hire a few more people who actually had some clue about the way science works.