In some ways war is a method to divide resources. War is probably inevitable until Earth provides unlimited resources.
"Global warming" is a catch-phrase for the changing environment (setting aside momentarily the always exciting argument over the cause). It is probably inevitable until Earth is more robust.
War is a method to divide resources, but so is trade. And those parts of the world that trade with each other by and large do not go to war with each other.
In fact, look at the history of the 20th century. Lots of wars between countries that believed in trade and countries that did not believe in trade: this is called the Cold War. After this we started getting wars between countries that were part of the global trading community and countries that weren't, over issues that would largely go away or be resolved peaceably if those countries joined the global trading community.
This is called "globalization", and it's what all those anarchists tend to start riots about every time the larger countries want to have a conference about it.
It really doesn't in the long run, but it turns out you get so many more net resources through trade anyway that even in a shortage you're better off with trade than war.
"Global warming" is a catch-phrase for the changing environment (setting aside momentarily the always exciting argument over the cause). It is probably inevitable until Earth is more robust.