" Does life on Earth have a future?"

By “life on Earth” I mean the variety of life, the multitude of species, the dazzling array of ecosystems they create from the permanent snow fields of the Himalayas to steamy jungles, and coral reefs, and the variety of including ourselves including and the 6000+ languages we speak and our cultures that they largely define.

There are two answers: no and yes.

A median estimate is that a third of all the species will be on the fast track to extinction within the next quarter century. Over 90% of all languages will be gone by then, because languages spoken by fewer than a million people are rarely taught to children. Most tropical forests will be gone by 2025 and with them, their species and peoples. Global warming will ensure that the species that survive do so in the wrong place. Coral reefs will be cooked alive in too-warm oceans, tropical glaciers will long have been only a memory preserved in the National Geographic photo collection.

So what will it mean for humanity to live in such a biological impoverished world? I always think of Orange County, California, with an airport named after an actor. A fake cowboy/war hero (delete as appropriate) to introduce you to a desert world with nitrogen-enriched green lawns, no sidewalks, golf courses, imported water. Instant gratification reigns. The future? Don’t worry be happy. Enough people like that world; property values are high.

But suppose we saved the variety of life on Earth, grabbed the nettle of global warming, and, in general thought about our human futures. What would that tell us about ourselves — and what we are capable of achieving? What would it take to accomplish that?

Answer the life-on-Earth question and whatever answer one picks, so much about ourselves must be revealed.

Stuart Pimm is Professor of Conservation Biology at Columbia University in New Yorkand author of The World According to Pimm: A Scientist Audits the Earth.