“Rhino-mounted Bantu shock troops could have overthrown the Roman Empire. It never happened.”

“Rhino-mounted Bantu shock troops could have overthrown the Roman Empire. It never happened.”

“Take air quality in the United States today: It's about 30 percent better than it was 25 years ago, even though there are now more people driving more cars.”

“Federal elections happen every two years in this country. Presidential elections every four years. And four years just isn't long enough to dismantle all the environmental laws we've got in this country.”

“I decided that now is the time to start doing the things that really interest me and I find important. It was in the 10 years of the MacArthur grant that I began working on my first book... and I began putting more work into environmental history.”

“Technology has to be invented or adopted.”

“The broadest pattern of history - namely, the differences between human societies on different continents - seems to me to be attributable to differences among continental environments, and not to biological differences among peoples themselves.”

“Biology is the science. Evolution is the concept that makes biology unique.”

“Thousands of years ago, humans domesticated every possible large wild mammal species fulfilling all those criteria and worth domesticating, with the result that there have been no valuable additions of domestic animals in recent times, despite the efforts of modern science.”

“Lest those islands still seem to you too remote in space and time to be relevant to our modern societies, just think about the risks... of our increasing globalization and increasing worldwide economic interdependence.”

“I've worked very hard in this book to keep the lines of communication open. I don't want to turn someone away from this information for partisan political reasons.”

“In much of the rest of the world, rich people live in gated communities and drink bottled water. That's increasingly the case in Los Angeles where I come from. So that wealthy people in much of the world are insulated from the consequences of their act”