"The key to understanding overpopulation is not population density but the numbers of people in an area relative to its resources and the capacity of the environment to sustain human activities; that is, to the area’s carrying capacity. When is an area overpopulated? When its population can’t be maintained without rapidly depleting nonrenewable resources.... By this standard, the entire planet and virtually every nation is already vastly overpopulated."

“In fact, giving society cheap, abundant energy at this point would be the moral equivalent of giving an idiot child a machine gun. With cheap, abundant energy, the attempt clearly would be made to pave, develop, industrialize, and exploit every last bit of the planet—a trend that would inevitably lead to a collapse of the life-support systems upon which civilization depends.”

“Too many rich people in the world is a major threat to the human future, and cultural and genetic diversity are great human resources.”

“A series of things have come up since then that have made the problem incredibly grimmer…. The ozone hole… acid rain…. Three hundred million people have starved to death since THE POPULATION BOMB was written. The famines weren’t as large as agriculturists thought they would be… due to the spread of… Green Revolution technology into the poor countries…. What makes us nervous right now is that we’re faced with again having to do something desperate to increase our food production greatly.... In 1965 we knew exactly how to do it, the question was could we deploy it fast enough—Today we have nothing left to deploy—that’s very scary.... As a species we’re not able to live on our income; we’re living on our capital, our deep rich agricultural soils are being destroyed, water is being overpumped, and our biodiversity, our life support system—we’re already far beyond what we can support.”

“Growthmania is the fatal disease of civilisation - it must be replaced by campaigns that make equity and well-being society’s goals - not consuming more junk.”

“The debate regarding which individual factor, among the three key factors producing the environmental crisis, causes more damage - the size of the human population on the planet, excessive consumption of resources or unequal/ unjust distribution of resources among countries - is like a debate about which contributes more to a triangle, the base or the ribs of the triangle. You can not separate the three factors. If we analyze the numbers over a relatively longer time interval, we will conclude that the size of the population has a bigger impact than consumption. On the other hand, consumption and unequal distribution are also important aspects. If we do not change these three factors all at the same time, the quality of our life will change dramatically. Today humanity is delivering a serious blow to nature, but it is clear that nature will deliver the final blow.”

“The evidence we have is that toxics reduce the intelligence of children, and members of the first heavily influenced generation are now adults. The first empirical evidence we are dumbing down Homo sapiens were the – and the resultant. On the other hand, toxification may solve the population problem, since sperm counts are plunging.”