It's what's called an exponential, it's flat for a long time and then... boom! it's an increase in population, increase in technology, increase in pollution increase in our powers to disturb the environment to change the planetary environment but we're the same old human beings as we were a thousand years ago or a hundred thousand years ago, not much has changed with us and so it's very hard for us to catch on that there's a new situation, and we have to adapt to it.