Potential for Disaster

If mankind makes the transition to a space faring civilization, we will then have excess to unlimited resources and our population could grew expoetially with a high standard of living for billions of years.
If we, however, continue to increase our numbers unabated on one planet, a disaster of some kind is inevitable.
Look at current trends. All throughout the world, per capita consumption of the global middle and upper class is increasing. Meanwhile, the amount of usable farmland is lessening, the world fisheries are being depleted, and freshwater supplies are diminishing.
Couple these trends with population growth and the inequality of wealth and you have the prescription for disaster. There is little chance of avoiding it.
The ultimate question is not if population is going to be kept under control, but how. Is it to be through voluntary family planning or decease, starvation and genocide? Something has to give.
Colinizing space and exploiting its limitess resources is an the ultimate long term solution, but given the technological hurdles and expense, it may be centuries before it happens.
Until then, we will have to learn to control our numbers and live more sustainable.