When you don't know what to do and every possible course of action seems wrong, study Kohelet (Ecclesiastes). Although tradition holds that King Solomon wrote it, modern scholars attribute it to one or more of his civil servants. It gives, in general, the same advice that Harold Nicolson gave to a young acquaintance who felt trapped and buffeted in a civil-service position: do your job and be meticulous in everything that you can control. The edition of Kohelet that I recommend is The Tao of Solomon by Rabbi Rami Shapiro.
I was thinking of this because of a presentation that the Rev. Michael Dowd gave recently in our community. He spoke forcefully about the inevitability of drastic climate change: that, regardless of anything we do, the amount of carbon already in the atmosphere makes a much hotter world inevitable. Worse, some of the effects of a hotter climate, such as forest fires and melting of polar ice, themselves release even more carbon into the atmosphere.
He also argues that technology won't save us and that faith in progress is actually harmful: the damage has already been done. Nevertheless, this doesn't mean that we should take no action. Things we do now (carbon fee, renewable energy, conservation) won't stop climate change, but that is not reason to continue making it worse.
Yet Michael doesn't consider himself a prophet of doom. He calls himself a post-doom, pro-future evangelist.
As my friend and colleague Malachi Doane points out, we Jews have some experience with rebuilding life after disaster. The classic example is the refashioning of Judaism after the destruction of the second Temple in 70 CE, led by Rabbi Johanan ben-Zakkai and others at Yavneh, outside Jerusalem. They changed Judaism from a religion centered on animal sacrifices in the Temple to one with a God who did not need sacrifices but demanded righteous living. We could also cite the rebuilding of Jewish life after the Holocaust, including the so-called 614th commandment: not to give Hitler a posthumous victory (through despair).
The question, therefore, is what we should do, what I (as a spiritual educator) should do.
My first thought is: help us equip ourselves against nihilism and despair. This especially applies if you teach or lead young people. While adults head straight to denial, it's common for teens and pre-teens to pitch headlong into despair, which can lead to a personally disastrous life course. In young people it could well be drugs or suicide; in adults it might be wanton abandon, heedless consumption.
Activism, even though it will not solve the problem, is the best alternative to despair.
My next thought is to teach religious limits more in accord with the "carrying capacity" of the planet (inherent limits). As Michael says, future religion should emphasize limits on consumption and degradation of the biosphere. I've suggested, in a conference presentation and article, that Judaism--very much a religion of limits--should redefine kashrut to limit the consumption of meat to Shabbat and Yom Tov, a practice that economic circumstances and agricultural reality imposed on most of our ancestors. A practice also suggested by existing eco-kashrut is to limit our meat consumption to grass-fed animals.
A third thought is to introduce both young and adult learners to Jewish spirituality that is God-centered in a radical sense: one that is congruent with, and embraces, reality. In the same way that we believe that is is valuable to pray for, or recite Tehillim (Psalms) for a person who is gravely ill even if we don't believe that prayers or psalms will effect a cure, we should understand everything and anything we do to protect the environment and reduce carbon emissions as holy acts.
Fourth (and finally), Judaism is already a religion that passes wisdom forward, but we need to incorporate contemporary, scientific wisdom into the culture that we give the future. We do not know what human life a century or two from now will look like. We don't know for sure that there will be Jews then. It's incumbent on us now, however, to figure out what wisdom we want Jews (and all people) of the future to value and to figure out ways to preserve and transmit it. This is a Yavneh moment. What would Rabbi ben-Zakkai do?