When humans over-exploit underground water supplies, the ground collapses like a huge empty water bottle. It's called subsidence, and it could affect 1.6 billion people by 2040.
Conflict forced scientists to abandon a gene bank, but not before duplicating their last remnants of essential crops in the Svalbard vault on a remote Arctic island.
If the U.S. brought back the Great Depression’s massive worker program, it could put millions of Americans back to work — and help stave off disasters like wildfires.