• First, that since about 1800 economic development has been based on the burning of fossil fuels, and this will continue to apply for the foreseeable future.
• Second, due to momentum in economic, demographic, and climate processes, it is inevitable that there will be a major rise in the level of atmospheric CO2 during the twenty-first century.
• Third, available data on global temperatures ... suggest strongly that the coming warming of the Earth will be appreciably faster than anything that human populations have experienced in historical times. ... Furthermore, particularly in a system that is being forced, the chances of an abrupt change in climate happening must be rated as fair.
• Fourth ... the range of plausible unpleasant climate outcomes seems at least as great as the range of more manageable ones. The agricultural, political, economic, demographic, social and other consequences of future climate change are likely to be considerable - indeed, they could be almost inconceivable. In a world of perhaps nine billion people, adverse changes could well occur on several fronts simultaneously and to cumulative adverse effect.
• Finally, the paper argues that human experience of other difficult 'long wave' threats (e.g. HIV/AIDS) reveals a broadly analogous sequence of reactions. In short: (i) scientific understanding advances rapidly, but (ii) avoidance, denial, and reproach characterize the overall societal response, therefore, (iii) there is relatively little behavioral change, until (iv) evidence of damage becomes plain. Apropos carbon emissions and climate change, however, it is argued here that not only is major behavioral change unlikely in the foreseeable future, but it probably wouldn't make much difference even were it to occur.

Ugh.

There are only a few places to find some wiggle room in this argument.

It's true that historically, prosperity has been tightly correlated with use of fossil fuels. But it's at least theoretically possible that fossil fuel use could decline sharply, through a mixture of efficiency and other, cleaner sources being brought online. It's also true that much of the damage has been done -- the greenhouse gases already heaped on the climate will continue to have effects for many decades to come, even if we completely halt CO2 emissions tomorrow. But perhaps if we quit adding CO2, the climate changes will be slow enough for us to adapt without catastrophic disruption. Of course, both these would rely on the fifth point being wrong, or rather, describing a pattern that we might be able to break this time. Perhaps the impacts of climate change are obvious enough in far-off regions like the Arctic for us to get a head start on dealing with it.

Anything could happen. The future is unpredictable. But Dyson's paper is a stark, cold reminder of just how high the odds are stacked against us.

(For a little counterbalancing optimism, read Mark Bahner's comments under Pielke's post, or just, you know, go read Worldchanging.)