Humans are generally very risk-averse. We buy insurance to protect our investments in homes and cars. For those of us who don't have universal healthcare, most purchase health insurance. We don't like taking the chance -- however remote -- that we could be left unprepared in the event that something bad happens to our homes, cars, or health.
Climate change seems to be a major exception to this rule. Managing the risks posed by climate change is not a high priority for the public as a whole, despite the fact that a climate catastrophe this century is a very real possibility, and that such an event would have adverse impacts on all of us.
For example, in my job as an environmental risk assessor, if a contaminated site poses a cancer risk to humans of more than 1-in-10,000 to 1-in-1 million, that added risk is deemed unacceptably high and must be reduced. This despite the fact that an American man has a nearly 1-in-2 chance of developing and 1-in-4 chance of dying from cancer (1-in-3 and 1-in-5 for an American woman, respectively).
To that 42 percent chance of an average American developing cancer in his or her lifetime, we're unwilling to add another 0.001 percent. The reason is simple -- we really, really don't want cancer, and thus consider even a small added risk unacceptable.
Yet we don't share that aversion to the risks posed by human-caused climate change. These risks include more than half of global species potentially being at risk of extinction, extreme weather like heat waves becoming more commonplace, global food supplies put at risk by this more frequent extreme weather, glaciers and their associated water resources for millions of people disappearing, rising sea levels inundating coastlines, and so forth.
This isn't some slim 1-in-a-million risk; we're looking at seriously damaging climate consequences in the most likely, business-as-usual scenario. The forthcoming fifth IPCC report is likely to state with 95 percent confidence that humans are the main drivers of climate change over the past 60 years, and the scientific basis behind this confidence is quite sound. It's the result of virtually every study that has investigated the causes of global warming.