Albert Einstein, physicist

“Overpopulation in various countries has become a serious threat to the well-being of many people and a grave obstacle to any attempt to organize peace on this planet of ours.”

Stephen Hawking, physicist

"With climate change, overdue asteroid strikes, epidemics and population growth, our own planet is increasingly precarious,"

Dame Jane Goodall

"It’s our population growth that underlies just about every single one of the problems that we’ve inflicted on the planet. If there were just a few of us, then the nasty things we do wouldn’t really matter and Mother Nature would take care of it — but there are so many of us."