ABSTRACT
One of the most striking features of the global warming debate has been how, with each advance in climate science, the news keeps getting worse. Although temporarily slowed by the effects of the 2008 global financial crisis, the world’s greenhouse gas emissions have been growing much faster than predicted in the 1990s. In addition, since 2005 a number of scientific papers have described the likelihood of the climate system passing significant ‘tipping points’ beyond which the warming process is reinforced by positive feedback mechanisms-small perturbations that cause large changes.1 This new understanding has upset the comforting idea of a ‘dose-response’ relationship between the amount of greenhouse gases we put into the atmosphere and the amount of global warming that follows. That idea has allowed us to believe that, although we may be slow to respond, once we decide to act we will be able to rescue the situation. In truth, it is likely that in the next decade or so, beginning with the melting of the Arctic’s summer sea-ice, the Earth’s climate will shift onto a new trajectory driven by
‘natural’ processes that will take millenniums to work themselves out.
