A mass extinction is simply defined as an unusually large loss of biodiversity over a very short time interval. I think that’s an accurate description of the way our world is changing today. He spoke with EarthSky about what many of calling the catastrophic loss of biodiversity going on now. I’m not worried about, you know, the rise of evolutionary monsters, quite the contrary, I think I’m most worried about the loss of familiar. By some estimates, he said up to 50% of species are predicted to disappear in the next 100 years. He said human activities are driving species loss. He thinks today’s loss of biodiversity will change the way the world works, but that humans will still be around in centuries to come. To the extent that optimism proves justified, it’s going to be because talented people take up the challenge to rethink energy, rethink agriculture, rethink, basically, the way we live.