The U.S. is expected to announce today that it will contribute to a U.N. effort to address the problem of indoor wood cookstoves whose smoke kills an estimated 1.9 million people annually.

"SUKKUR, Pakistan — Suhani Bunglani fans flies away from her two baby girls as one sleeps motionless while the other stares without blinking at the roof of their tent, her empty belly bulging beneath a green flowered shirt. Their newborn sister already died on the ground inside this steamy shelter at just 4 days old, after the family's escape from violent floods that drowned a huge swath of Pakistan. Now the girls, ages 1 and 2, are slowly starving, with shriveled arms and legs as fragile as twigs."

"The new UN humanitarian chief has warned that after the Asian tsunami, the Haiti earthquake and the Pakistan floods, the world must brace for a growing number of disasters that will need a new battle campaign."

"The ozone layer that shields life from the sun's harmful rays is projected to recover from harmful chemicals by mid-century, but it will take longer over the polar regions, a United Nations study said on Thursday."

"So far, 2010 is tied for the warmest year on record, and Arctic sea ice reached its third-lowest level, prompting thousands of walruses to haul themselves out of ice-starved waters, U.S. scientists said on Wednesday."

"Asia's tiger population could be close to extinction with fewer than 3,500 tigers remaining in the wild and most clustered in fragmented areas making up less than 7 percent of their former range in Asia, a study says. The study in the latest issue of the online journal PLoS Biology says saving tigers living in 42 sites across Asia from poachers, illegal loggers and the wildlife trade is crucial to prevent the species becoming extinct in the wild."

"Decades of overfishing have deprived the food industry of billions of dollars in revenue and the world of fish that could have helped feed undernourished countries, according to a series of studies released on Tuesday."

"A trio of potentially dangerous storms swirled over the Atlantic Ocean on Tuesday, as Tropical Storm Karl formed in the Caribbean on a path that could take it over oil-production facilities in Mexico's Bay of Campeche."

"From foxes to whales to walruses to plankton, Arctic species are being pushed toward extinction by rapid climate change, finds a new report by two conservation groups."

"The federal government declared in April that basking sharks in the Pacific Ocean are a 'species of concern,' which means the government doesn't yet have enough information to say the giant fish is threatened or endangered, but it might be."