Global Warming

Scientists propose giant air conditioning system to 'refreeze' the Arctic

Critics weigh in on Al Gore's 'An Inconvenient Sequel'

Birds are migrating earlier as global temperatures rise

Polar vortex: It's baaaaack!

Carbon dioxide in Earth's atmosphere just reached a major milestone

7 reasons why Arctic sea ice matters

Extinct smallpox virus could be resurrected by global warming

Melting ice could expose Cold War toxic waste

Are wildfires getting worse?

Sweltering 2016 is a warning from the future

What are megaslumps, and how do they threaten our planet?

As U.N. makes history on Earth Day, Leonardo DiCaprio reminds us not to rest on laurels