The process is sufficiently slow that an individual, especially an older individual of the sort who make up legislatures and other influential institutions, can reasonably expect to die before it does him significant personal harm. Therefore it is fairly easy for such an individual, if given the proper incentives, to dismiss or deny it. As long as there are fossil fuels in the ground that can be extracted profitably, the proper incentives exist. Whether the dismissal represents a genuine belief or simple rapaciousness is irrelevant (and it's doubtful even the deniers themselves know which).
It is quite likely that this phenomenon will continue even when the baseline conditions (those that existed during someone's youth) have degenerated dramatically relative to modern-historical norms. It's the incremental harm over the remainder of an individual's lifetime that matters, against the profits he stands to make from maintenance of the status quo. As long as that's a net win, you will have deniers (the alternative explanations or reasons offered for doing nothing may change, of course, but those aren't important anyway). They'll go away only when the rate of warming is so rapid as to make denial both utterly laughable and obviously unprofitable, at which point human extinction will probably be no more than a few centuries away.
Extinction is unlikely, given the vast amount of energy we have at our disposal (even if that energy's consumption is making it hard to be a biological construct on this earth).
No, the likely scenario is in some ways even sadder: the 1% will survive in carefully-cultivated bunkers by the thousands or tens of thousands, and the vast majority (along with an awful lot of the other life on the planet) will die.
Extinction by this effect is a possibility, but a remote one; humans react faster than the climate, and we're very good at problem solving over time when faced with existential threats. We're just bad at predicting them and solving them when they're on the horizon and a gentle nudge could have desired cumulative effect.
Unfortunately, in the past 5 years we have begun to understand the possibility that runaway greenhouse events from methane release are a not-insignificant detail which most models do not account for.
Researchers who have been working on that area have basically said that if the conditions for oceanic methane clathrate relase is met, everything could change in the span of two decades.
> The projected net impact from global warming is on the ~$2T/year range.
Such projections obviously assume that the warming stops at some point. I don't really see any reason to believe it will, at least not as long as a significant number of humans remain. Whether enough humans will die off before the effect becomes self-sustaining is still TBD.
The process is sufficiently slow that an individual, especially an older individual of the sort who make up legislatures and other influential institutions, can reasonably expect to die before it does him significant personal harm. Therefore it is fairly easy for such an individual, if given the proper incentives, to dismiss or deny it. As long as there are fossil fuels in the ground that can be extracted profitably, the proper incentives exist. Whether the dismissal represents a genuine belief or simple rapaciousness is irrelevant (and it's doubtful even the deniers themselves know which).
It is quite likely that this phenomenon will continue even when the baseline conditions (those that existed during someone's youth) have degenerated dramatically relative to modern-historical norms. It's the incremental harm over the remainder of an individual's lifetime that matters, against the profits he stands to make from maintenance of the status quo. As long as that's a net win, you will have deniers (the alternative explanations or reasons offered for doing nothing may change, of course, but those aren't important anyway). They'll go away only when the rate of warming is so rapid as to make denial both utterly laughable and obviously unprofitable, at which point human extinction will probably be no more than a few centuries away.