Do you think there are too many people in the world? What should we do about it?

In the last 50 years (my lifetime) the population of the world has more than doubled from 3 billion to 6.5 billion, and by the time my children are around my age in 2040 the population will reach 9 billion or more. We cannot agree to feed 1 billion people now, and as oil-subsidised food declines and food prices rise, how will we take responsibility for another 3 billion people to feed? What do you think we can we do to limit population?