The missing piece in the jigsaw regarding humanity's response to climate change is the absence of a mass movement of the general public forcing/enabling the centres of power to take the action needed.
Quakers have always emphasised different testimonies in response to the challenges of the times. We prioritised equality when slavery was the issue. We prioritised peace when world war was the issue. Now the urgent issue is one of overconsumption, so maybe it's time for us to prioritise simplicity. In terms of Quaker history, maybe the Age of Equality and the Age of Peace need to make way for an Age of Simplicity.
In order to uphold these testimonies, Quakers had to go through an often trying period of internal discernment and threshing. Once that was done, we became united, active, and vocal enough in the world outside to contribute to the change which occurred. This had benefits for us as a worshipping community and obviously it also did good in the world at large. It's good for us spiritually as a community to have a real challenge to face, and we do most good in the world when we face it.
So maybe we need to become a people campaigning for simplicity in the way we have been a people campaigning for peace or equality. I see the beginnings of this among Quakers at the moment, but maybe we could/should go further?
I might write at more length on this when I get time.