There seems to be a general consensus that the human race should act responsibly in the natural environment, given that man-made activities have an impact on the climate. Indeed, it is decidedly easy to show that man-made activities have some impact on the climate. The trouble is, however, that it is extremely difficult to quantify this impact reliably.
For this and other reasons, uncertainty plays a central role in this business, and it should therefore be treated properly, with the respect that it merits. In particular, we should refrain from using voodoo decision theories in dealing with the uncertainties associated with climate change.