Is Earth Past the Tipping Point?

For 10,000 years, our world seemed endless. The sky was the limit. But today’s world looks much smaller. We’ve cleared, consumed and polluted our way across the globe. The planet is shrinking. Have we pushed Earth past the tipping point? That’s a critical issue we explore in our second Big Question video, which draws on research from “Planetary Boundaries: A Safe Operating Space for Humanity,” published this past fall in the journal Nature.

http://www.scientificamerican.com/article.cfm?id=boundaries-for-a-healthy-planet