Seen through the prism of responsibility and power (which I discussed in my last post), scientists and environmental activists are operating from a position of high responsibility, and trying to gain enough power to match it, while the climate deniers have high power and are trying to avoid responsibility by rejecting the impacts of their actions. Scientists are working on increasing responsibility among others, in the hope that they will turn their existing power toward meeting it. Deniers, not recognizing the legitimacy of responsibility, see them as fakes who are competitors for power.
Mixed into all this is a difference in tolerance for uncertainty. Scientists recognize that they will never be totally successful in their quest to understand the way the world works, and are able to live their lives with the knowledge that some day what they think they know may be proven false. There are others, however, such as the deniers and their audience, who can't stand uncertainty; they need to have black-and-white answers, even if those answers are more imaginary than real.
The recent debt ceiling crisis demonstrated that politicians aligned with the climate deniers have an arguably sociopathic lack of conscience by their willingness to jeopardize millions of lives and risk world economic depression to gain more personal power. In a smaller scale example: If they were on the Titanic, they would have steered the ship toward the iceberg, locked everyone else in steerage, and taken all the lifeboats, all so they could be the only ones alive. Unfortunately, in the case of global warming, our whole planet is the Titanic. Extending the analogy, the lifeboats won't last long, and any hope of rescue is based on total fantasy (even if the deity they expect to rescue them did exist, he would more likely set their boats on fire than welcome them onto his heavenly island).
Seeing this, many of us who feel more responsibility than perhaps is personally justified, are getting increasingly stressed out by the imminence of the danger and shrinking time to mitigate its worst effects. Recent news about melting Russian permafrost, coupled with the dying of the oceans and its potential for unleashing a global holocaust that would wipe out most of life on our planet, adds to the sense of urgency while suggesting that it may already be too late. We feel obliged to try to save lives anyway, no matter what the probability of success and the personal distress it causes, because ultimately it's better to leave a legacy of more life than death.