News
Megadrought in the American south-west: a climate disaster unseen in 1,200 years
When the Nasa climatologist James Hansen testified before Congress in June 1988 about a warming planet, the temperature in Washington DC hit a record 100F. It was a summer of unprecedented heatwaves, and 40 states were grappling with drought.
Related Knowledge Center: Climate science
State of Play
What began as a theory in the 1890s — that industrial emissions of carbon dioxide could increase global temperatures — had progressed to a scientific fact a century later. Scientists across a range of disciplines are studying the impact of the still-growing concentration of carbon dioxide and other so-called “greenhouse gases” in the atmosphere as they call for industrial and governmental policies to slow, then halt, the warming of the planet.