Hells Angels and immigrant gangs clash; police and citizens struggle to find solutions.
Two new climate studies say that the US must cut carbon dioxide emissions by 90 to 95 percent to prevent the planet from becoming too warm.
The Asian Development Bank says the cost of inaction could be severe for the region's agrarian-based economies and rapidly growing coastal cities.
A recession may be a cruel remedy for environmental degradation. But some experts say the earth welcomes the breathing room.
Since 1970s, loose association of conservation-minded urban areas has grown up worldwide.
Rising sea levels and extreme storms could displace 480,000 people and damage businesses and airports, a new study says.