You may be too emotionally committed to listen to any skepticism, but for whatever it's worth:
1. Your language ("sin", "evil", "believe") indicates a major subjective component in what you're saying. As with everything subjective, you're probably aware that it's not provable with cold facts and logic, and it might justifiably be rejected by others' own subjectivity and take on facts.
2. A pervading feeling that the world is going to hell in a handbasket has proven seductive many times in history. Does any of this sound familiar:
"[They] claim that the current society and its rulers are corrupt, unjust, or otherwise wrong. They therefore believe they will be destroyed soon by a powerful force. The harmful nature of the status quo is considered intractable without the anticipated dramatic change"
Such world views have occurred often enough that there's a consecrated term for them: [1]. Sure, the different groups that held such beliefs differed from you in how they thought it would come to pass. But they differed from each other as well.
3. There's nothing necessarily theistic about millenarian beliefs. ("Official" churches have more often than not fought against them [3].) E.g. a lot of people in the 60s thought the apocalypse was due within two decades due to overpopulation.
4. Climate models have a simple, persuasive logic behind them. But that doesn't make them necessarily right. Malthusianism also had a seemingly bulletproof logic, yet the facts did not keep pace with it [4]. When the climate models turn out lacking precision [5], they also lose the force of scientific certainty. All we're left with is "the world is warming, we can't say how fast"; which is, of course, not a falsifiable belief [6].
[1] http://en.wikipedia.org/wiki/Millenarianism#Theology
[2] http://en.wikipedia.org/wiki/Population_bomb
[3] http://en.wikipedia.org/wiki/Millennialism#Reformation_and_b...
[4] http://en.wikipedia.org/wiki/Simon%E2%80%93Ehrlich_wager
[5] http://www.washingtonpost.com/blogs/capital-weather-gang/wp/...
[6] http://en.wikipedia.org/wiki/Falsifiability