You always can blame any particular difficulty on something that is not overpopulation. Nobody ever dies of overpopulation. They die of famine, pestilence, and war. There is always some proximate cause.
Overconsumption is the issue, not overpopulation. The number of people is not what degrades the earth; it's the number of people times the flow of energy and material each person commands. The ecological footprint of the average American is 13 times that of the average Indian. The 4 million babies born in the USA in 2000 will have twice the earthly impact of the 26 million babies born in India.