According to Harvard University Professor of Psychology Daniel Todd Gilbert, the human mind systematically and routinely misjudges certain types of threats. More specifically, years of evolution have hard-wired our brains to recognize certain, very specific types of threats. While useful for the natural selection of our early hominid ancestors, this hard wiring comes at the expense of not recognizing some other types of threats.

The first type of threats that we instinctively respond to is those that are personal and intentional. We are ever vigilant and alert to predators and potential enemies, such as wolves and competitors with big clubs. This is why our attention goes into hyper-drive when we see a snake in the woods, or why we experience such a primal response when we encounter aggressive behavior.

The second type of threat to which we're hard-wired to react surprised me. We instinctively respond to threats that we perceive as immoral or disgusting. Of course, what's "immoral or disgusting" is usually an evil in the eye of the beholder and doesn't necessarily relate to survival, so those types of threats don't seem like things that natural selection would favor. But this is exactly why people react so emotionally to the sexual practices of others, even those that are done in private and don't affect any one else (evil's apparently in the hole of the behinder). I think the roots of a lot of intolerance can be found in this tendency of mind.

Finally, it has been shown that we respond strongly to those threats that are imminent and require immediate action, and conversely, we are not at all sensitive to threats that are gradual and don't require immediate action. It seems that procrastination is built into our defense system.

These tendencies of mind may explain why we are blind-sided by climate change, as well as how we react to the warnings about climate change. Global warming is, if anything, non-personal (it affects all of us) and non-intentional (no one's releasing greenhouse gases to deliberately change the climate). It's no wonder that we don't react to our planet being on figurative fire than we do to our house being on fire. And climate-change deniers have called global warming "the greatest hoax ever perpetrated on the American people," and the product of some sort of vaguely socialist plot. In other words, they've come to consider the other side of the so-called debate ("so-called" because the debate is political, not scientific) as immoral and disgusting. Just ask a denier what they think about Al Gore and you'll see what I mean.

So even though we have the necessary intelligence and science to be cognizant of the danger ahead of us, we're not wired to perceive as a threat. It doesn't resonate with us the same as, say, illegal immigrants and terrorists (enemies with big clubs), or gay marriage and drug use (immoral and disgusting behavior).

It's the "gradual" part that might finally wake us up. Every time a new study comes out, it seems that predictions of the timing of events are even more imminent. This summer's heat waves and floods are starting to manifest an immediate threat impacting literally millions of people, and this imminent and immediate emergency may finally spur us on to action.