"The top U.S. environmental regulator said she was 'very concerned' about fluids blamed by some for polluting water supplies near sites where drillers use them to extract natural gas from shale deposits."

"The national oil company created after the 1938 seizure, Pemex, is entering a period of turmoil. Oil production in its aging fields is sagging so rapidly that Mexico, long one of the world's top oil-exporting countries, could begin importing oil within the decade."

"San Joaquin Valley farmers hope for $3.3-billion dam and reservoir at Temperance Flat, but they need help paying for it."

"Two billion people worldwide do their cooking on open fires, producing sooty pollution that shortens millions of lives and exacerbates global warming. If widely adopted, a new generation of inexpensive, durable cook stoves could go a long way toward alleviating this problem."