A global surge in avian flu outbreaks in birds and some mammals is worrying poultry farmers, scientists, and health experts. The trend is provoking questions about the future of the disease and globa…

See how six countries are faring amid efforts to protect 30 percent of the planet’s land and waters by 2030, and what will be saved if they succeed. 

The sprawling U.S. water system is central to the nation’s economy, but chronic underinvestment, increasing demand, and the consequences of climate change have revealed the system’s weaknesses.  

Conceived as the principal defenders of the 1979 revolution, the Islamic Revolutionary Guard Corps has evolved into an institution with vast political, economic, and military power.