THE POLICY QUESTION IS EASIER THAN THE SCIENCE QUESTION, RIGHT?
Human activity produces so-called green house gasses (GHG). In quantity, these can change the climate of the earth. GHG don't naturally 'go away' but are cumulative.
Therefore, it is prudent to stabilize the amount of GHGs related to human activity, one way or another.
So, from a policy perspective, call that the argument-from-prudence, even if it may be geo-politically difficult (burden sharing) and econ-politically divisive (vexing externalities) in its wider implications.
Wait for the science?
Well, science might tell us at what level GHGs actually become detrimental, so that we wouldn't waste money containing the problem at *cumulative* levels that may be relatively benign.
However, the science of measurement will likely spread its wings too late, not only because we have no way to downsize the clock-ticking, cumulative GHG volumes once a 'critical' point has been decisively observed (or unwittingly let pass by) but also because we have only a very rough calibration of our models to lend decisiveness.
Anyway, another six years go by and the scientific dipstick comes up, again.
It says that it is unequivocal that "most" of the recent increase in global temperature is due to human activity. Also, given the long swings in the earth's temperature that created ice ages, etc., we don't know, but we think that, based upon the examined history of 1,300 years that the current hot period is "likely" outside the norm of non-human induced, earthy temperature swings (i.e. 33% chance that we're wrong about that). Last, we are going to burn, drown, and starve if we don't do something about it, possibly.
sullylink
