Weather hasn't ever been in our control, so we've always just created micro-climates by enclosing an area. Whether we built a fire-warmed lean-to or a skyscraper with an HVAC system, we've just built systems that helped provide an environment better than the local default.

Similarly, we've never been able to cartelize production of global warming gases. Russia seems like it will benefit inordinately from global warming as its ices melt, the Northwest passage opens up, and it continues to sell off it oil and gas resources. Since Russia's a nuclear power, it seems like the proverbial 800-pound gorbear, which means we'll end up with whatever a globally warmed climate looks like.

The vast expanses of Earth will probably see different weather with more pollution. People will have even more incentive to move into cities where the costs of environmental dialysis will be lower due to economies of scale in process and shared infrastructure.

Just like laptops now, the biggest problem of our ultra-urban future will probably be waste heat. Packing millions of high-energy-use humans together in a separate environment will generate large quantities of heat which will probably be dumped into the outside world, just as our current air conditioning does. Though, we'll likely make some use of that heat.

Given the current state of the world, this will probably (and hopefully) work out without too much disruption.