Climate change is the epic challenge of our lives, and community leaders like Rahwa Ghirmatzion and Zelalem Adefris are already working on sustainable, resilient solutions. Through their organizations in Buffalo and Miami, they're focused on durable, affordable housing for under-resourced communities, the most vulnerable to the instability of cl...

The world around us is mainly made of two things: nature and the materials that we extract from it. To fight climate change, we need to protect and regenerate nature and transform materials into low- or zero-carbon alternatives. Session 4 of the Countdown Global Launch, hosted by Prajakta Koli and Hannah Stocking, features Thomas Crowther, Ernes...

Witness the unveiling of Countdown, a major global campaign to cut greenhouse gas emissions. TED has partnered with scientists, policy makers, organizations, activists and more to create an initiative that everyone in the world can be part of. Check out http://countdown.ted.com to learn how you can get involved — and help turn the tide on climat...