Climate change uncertainty is no reason for inaction since we can't rule out risk

Tim Palmer in the Guardian (UK) raises such an important point about risk that I’m breaking my unwritten rule to not link to the same media outlet twice on the same day: Climate change is sometimes presented in simple black and white terms. You either believe it or you don't. Perhaps after the recent controversies over email leaks and melting Himalayan glaciers, some may have decided to change camp. But this is a false dichotomy…

…Some, perhaps those without scientific training, may see probabilistic predictions as an evasion of responsibility. However, in reality, probabilistic predictions embody the scientific method. In any case, what is better for decision making, a forecast with some realistic measure of uncertainty, or some grossly overconfident prediction with no hint of uncertainty? Worldwide, probabilistic weather forecasts are now used by those making decisions to evacuate people exposed to river flooding, or to intense storms. For better or for worse, they are also central to who trade on future energy prices and other weather-sensitive commodities.

…We don't have to believe that our house will burn down in the coming year to take out insurance. Similarly we don't have to believe that dangerous climate change will occur to take action to cut emissions. A key question that everyone concerned by the climate change issue should ask, particularly those who are sceptical, is this. How large does the probability of serious climate change have to be before we should start cutting emissions?...

…The scientific method is sometimes described as "organised scepticism", and this, rather than some logical progression from one certainty to the next, characterises the inherently uncertain path of scientific progress. As one leading climate scientist put it: "In truth, we are all climate sceptics." However, despite the climate scientists' best efforts at scepticism, it simply has not been possible to rule out the risk of the sort of climate changes discussed above.

Handling uncertainty is key to the scientific method, but, conversely, the existence of uncertainty is not itself cause for inaction.

Buster Keaton wrestles with a railroad tie in The General