Much as Cold War nuclear strategists could argue about winning a nuclear war by having more survivors, advocates of a Global Warming War might see the United States, Western Europe, or Russia as better able to ride out climate disruption and manipulation than, say, China or the countries of the Middle East.
Everything we think about regarding sustainability - from energy to agriculture to manufacturing to population - has a water footprint. Almost all of the water on Earth is salt water, and the remaining freshwater supplies are split between agricultural use and human use - as well as maintaining the existing natural environment.
Back in the 1500s, the culture that we had built in the West embraced multigenerational projects quite easily. Notre Dame. Massive cathedrals were not built over the course of a few years, they were built over a few generations. People who started building them knew they wouldn't be finished until their grandson was born.