Paul Ehrlich

"In this the 21st century, ignorance is a choice."

"We are in a permanent state of overshoot in this country, in this world."

"Growth is the ideology of the cancer cell."

"The greatest tragedy of the human species is that we have never believed each other's bad news."

"If we don't figure out a way to create prosperity that doesn't destroy the planet, we're doomed."

"The basic biological fact is that no creature can overshoot its environment permanently."

"All the signals that human beings have learnt to read have been produced by other human beings."

"We are sawing off the limb that we are sitting on."

"The capacity to think ahead is the most important thing that separates humanity from other species."

"Every creature has an ecological impact; humans have learned to multiply ours exponentially."

"Sustainability is not negotiable if you want to inherit a viable world."

"The human population has grown to rival the size and complexity of the planet itself."

"Optimism in the face of apocalypse is not stupidity, it is a moral imperative."

"We must learn to think like mountains, for mountains have stood longer than we have walked."

"The only rational response to the state we're in is to be an optimist."

"What we do in the next ten years will determine the future of humanity."

"The real issue is not population growth or technology, it is our values and behavior."

"Nobody gets out of this world alive, but we can leave it better than we found it."

"Paying attention is a form of respect."

"The diversity of nature is not a luxury but a necessity for life itself."

"We must become the elders we wish to see in the world."

"Every choice we make is a vote for the world we want to create."

"The most dangerous myth is that technology will save us."

"Connection is not a luxury; it is the fundamental requirement of being human."

"We are the first species capable of understanding the consequences of our own extinction."

"The difference between being smart and being wise is knowing what matters."

"You cannot have infinite growth on a finite planet."

"Teaching people facts without shaping their values is dangerous."

"The precautionary principle should guide us: if an action might cause harm, the burden of proof falls on those taking it."

"We've created a civilization that requires its workers to be depressed."