Currently religion and non-religion are hot topics. The boundaries of left and right have dissolved on this issue. There are some on the political left unsparingly attacking Islam while others call for religious tolerance. The political right are not divided on this issue, some calling for the complete destruction of Islam, which is filled with some irony since many on the right who are Christian share certain values with Islam, for example, the subjugation of women to men and the denial of evolution.
Identification with a religion is decreasing among young people. So we have a mix of prevailing movements in religion. But what I'd like to describe here is what we might expect as the social order deteriorates under global warming. It's really happening even now in some parts of the world, Syria, South Sudan, Libya. Millions of people are in forced migration from wars and deprivation. Every day hundreds from North Africa trying to get to Europe, and hundreds more trying to get into the U.S. from Central America. And a new Islamic fundamentalism, ISIS, has appeared.
The deterioration of the social order in the Middle East has provided an opportunity for religious movements like ISIS. But this is just the beginning. What is happening the middle east will generalize to other parts of the world as the scarcity of food and water and local conflicts produces starvation and migration. Eventually northern cities will become enclaves surrounded by masses of hungry people in which the social order will undergo severe compromise.
The social institutions now concentrated in the cities will be absent among the environmental immigrants. This social vacuum will be filled by religious opportunists, much like ISIS in the Middle East, though in North America it will more likely be some version of Christianity, like Santeria or some form of Fundamentalism.
If nothing is done about global warming, eventually the remaining civilization in the cities will disintegrate and we will be left with a new dark ages. Science will be preserved in some dusty books in abandoned buildings to be read by some future survivors of global warming. And this time of not having to ascribe to a religion, to safely be atheistic, agnostic, or non-religions, will be gone.