What is mass extinction?
From the pre-launch Vox:
<blockquote> <p>Just to give one example that I think people can relate to, or understand, the Arctic ice cap, which has been there for millions of years, is probably going to be gone in your lifetime. You’re going to be able to go to the North Pole in the summertime and swim around, paddle around, if you were in the Polar Bear Club, or whatever. That is a huge change on the surface of the earth, and it will occur in the lifetime of a lot of people who are alive today.</p> </blockquote>