Detecting and responding to climate change

Detecting and responding to climate change are two interrelated aspects of an important activity that Bert Bolin strongly promoted: the communication between scientists, the public and policy makers. The demonstration of a statistically significant anthropogenic contribution to the observed global warming greatly increased the public acceptance of the reality of climate change However, the separation between human-induced climate change and natural climate variability on the regional scales of greatest relevance for human living conditions remains a more difficult task. This applies to the prediction of both the anthropogenic signal and the natural variability noise. Climate mitigation and adaptation policies must therefore necessarily be designed as the response to uncertain risks. Unfortunately, the political response to climate change has stagnated in recent years through the preoccupation with the global financial crisis. Climate scientists can help overcome the current climate policy impasse through the creation of a new generation of simple, actor-based, system-dynamic models that demonstrate the close connection between the stabilisation of the global financial system and effective climate policies. Examples are given of alternative stabilisation policies that can lead either to major recessions and unemployment or to stable economic growth supported by an accelerated decarbonisation of the economy.