The global economy coupled with the collective mental landscape means that this biosphere will be destroyed long before we really get off this planet. The current system, built on narrow nationalistic and corporate interests, simply lacks global long-term planning and implementation. The game that is played by the "short-term monetary profit is king" rule will eventually kill everything on this planet including us. Only 60% of the species that lived on this planet in the '50s survive today, and the extinction rate is rapidly accelerating, so after another 50 years, expect to be already rather close to 0%.

We'll never get to colonies on Mars. There's no quick profit in it. There is quick profit in, for example, digging up fossils and burning them and converting the heat into electricity. Consequently, carbon dioxide production is growing at an accelerating rate, despite the fact that it's probably already at a higher level than the biosphere can handle.

Martian colony in 40 years? Even if that happens (and it won't) it won't last without regular support from Earth. During the latter half of this century, as the ecosystem and civilization finally break down, that support will stop, and the theoretical colonists will perish.