What if you had to choose between saving large swaths of humanity from a "nasty, brutish, and short" existence and protecting the biosphere from the possibility of irrevocable harm? That's our present choice, says Freeman Dyson:
Beyond the specific points of factual dispute, Dyson has said that it all boils down to “a deeper disagreement about values” between those who think “nature knows best” and that “any gross human disruption of the natural environment is evil,” and “humanists,” like himself, who contend that protecting the existing biosphere is not as important as fighting more repugnant evils like war, poverty and unemployment.
No he's not talking about aid payments from the MDCs to the LDCs, but rather simply allowing LDCs to continue using dirty-but-cheap fossil fuels like coal to lift themselves out of poverty. If you'd prefer, you may think of this as trading off certain bad outcomes for people existing in the present and near future in exchange for preventing possible bad outcomes for people who might exist in the relatively-far future. (of course the magnitude of the two might not be equivalent.)
Via Wilkinson, who also lifts this quote:
To Dyson, “the move of the populations of China and India from poverty to middle-class prosperity should be the great historic achievement of the century. Without coal it cannot happen.” That said, Dyson sees coal as the interim kindling of progress. In “roughly 50 years,” he predicts, solar energy will become cheap and abundant, and “there are many good reasons for preferring it to coal.”
Of course, reasonable people can disagree about which is more important. But the point is that reasonable people cannot disagree that there are tradeoffs, and that policy choices in one area affect outcomes in others.
(Not that I should have to, but just to nip any partisan sniping in the bud: the above is true for all political orientations, and neither is more righteous in my view: there are good reasons to want to end present-day suffering, and there are good reasons for wanting to end future-day suffering. The point is to consider the tradeoffs.)