The timeline for economic damage (from global warming) is fairly long. Even in the worst-case scenario, the Earth as we know it is still recognizable for the next 50 years, and all of the seasons and climate patterns remain roughly the same. The major changes will tend to show 50 to a 100 years from now.
Also, I'd like to point out that the increasing acidity of the oceans is a much worse problem, in the long-term, than the warming of the atmosphere. Carbon washes out of the atmosphere, and ends up as acid in the oceans. At current trends, in less than 100 years the oceans will be more acidic than at any point since the Cambrian Revolution. It is not clear that life in the oceans can survive with those levels of acidity (other than organisms that live in volcanic vents and love acid).