ABSTRACT

It is increasingly clear that understanding human responses to climate change is just as important as – if not more important than – understanding climate change itself. We already know enough about anthropogenic (human-made) global warming to have triggered action to reduce CO2e1 emissions if our response was to be rational and not destructive. The question is, why is knowledge of climate reality being so resisted? In the West we, as societies, have known about anthropogenic global warming for at least 20 years, since NASA scientist James Hansen testified before the US Congress that the planet is heating because we are burning so much fossil fuel and hence emitting so much carbon dioxide (June 1988; Royal Society 2010). Stephan Harrison, in the final chapter of this book, outlines what we know about the science; he usefully divides his analysis into two sections: what we are more certain (in a scientific sense) about and what we are less certain about. Our certainties are the message that Hansen gave to Congress: that global warming is happening and is largely man-made. Our models of what this will lead to, when and with what regional variability are where most of the uncertainty lies.