Starting with a key (a psycho-socio-historico-technological[!]) insight -- that nuclear weapons were "born into the world...propelled by a momentum that no one knew how to stop (Einstein called it the "ghostlike character" of its "apparently compulsory trend") because the bomb's momentum was "rooted in the structure of the modern scientific enterprise" -- everything I've read so far in this book repays careful attention.
But Schell may be wrong in a distinction he makes between nuclear weapons and climate change. Regarding the latter he writes:
The question, complex in practice but simple in principle, becomes whether the unpleasant initial consequences [of anthropogenic climate change] can inspire political action fast enough to head off utter calamity later on.The problem here may prove to be that catastrophic changes are already locked into the earth system, and these cannot be headed off by action now in response to relatively minor effects we are seeing at present -- what should be the familiar stock and flow problem (see, e.g., here and here).
And on the bright side, we can imagine at least some scenarios in which limited nuclear exchanges lead to relatively co-ordinated and sensible responses -- more awareness of what David Hayes calls a “global we”, and less of the “trapped transition”.
[At this moment -- small, perhaps in the scheme of things, but remarkable for all that -- when real democracy has been manifest in a country where democracy seemed lost, there may a little hope, however transitory. (Eric Alterman, for example, raise his own hopes and those of some others when he writes: "nothing about...Obama's cool, almost non-partisan rhetoric...precludes his taking an extremely progressive direction as president.")]
P.S. 9 Jan: On being too late see Richard C. J. Somerville of the Scripps Institution of Oceanography, quoted here: “a dramatic shocking surprising climate event that is unambiguously due to global warming may be the only thing that motivates people and governments. Maybe a big chunk of ice sheet destabilizing and producing a significant sudden sea level rise. Unfortunately, then it may be too late, because it’s essentially irreversible; you can’t cool the world enough to make the ice re-form quickly.”