Global human population is around 75 million annually, or 1.1% per year. The global population has grown from 1 billion in 1800, to 7 billion in 2012. It is expected to reach 10 billion by the end of the century.
The last 100 years have seen a rapid increase in population due to medical advances and massive increase in agricultural productivity made possible by the Green Revolution.
The Green Revolution refers to a series of research, developments, and a sharing of technology among governments and universities that increased agricultural production worldwide.
The earth is 4.6 billion years old. Scaling to 46 years, we've been here 4 hours, and our Industrial Revolution began 1 minute ago. In that time we have destroyed 50% of the world's forests. This is not sustainable. Although this isn't directly a population issue, it is a factor.