RIO DE JANEIRO: Heavy rains over the past month have created a fertile breeding ground for mosquitoes carrying the dengue fever virus, deepening a crisis that has claimed at least 80 lives in the state of Rio. The dengue strain ravaging this tropical city is believed to be stronger and more deadly than the virus responsible for an epidemic in 2002, considered the worst in recent history in Brazil, according to Dr. Jacob Kligerman, health secretary for the city.

BEIJING: The fear of failing to grow enough corn, wheat or rice to feed its people has spurred China into action this year, but Beijing may be doing too little, too late to overcome the powerful forces of urbanization. Just as global grain markets grapple with ultralow stocks and record-high prices, China is battling to stem the destruction of its arable land due to urban sprawl, the growing scarcity of water and the exodus of labor to its booming cities by directing tens of billions of dollars to rural areas.

Out on the American farm, the ducks and pheasants are losing ground. Thousands of farmers are pulling their fields out of the government's biggest conservation program, spurning guaranteed annual payments for a chance to cash in on the boom in wheat, soybeans, corn and other crops. Last fall, they took back as many acres as are in Rhode Island and Delaware combined.

Two of the biggest oil companies in the world, BP and ConocoPhillips, have joined forces to try to break a longstanding deadlock over the vast reserves of natural gas in Alaska. The firms said they would spend billions to build a pipeline from the North Slope to feed markets in the United States and Canada. The proposal Tuesday won praise from Alaska's governor, Sarah Palin. "It's a good day," she said to reporters.

DUNDALK, Ireland: When the fearsome Cuchulainn was transformed by the rage of battle into a Celtic Incredible Hulk, according to Irish mythology, the warrior's intensity melted snow for 30 feet around him. That was an impressive generation of alternative energy from this Achilles-like hero so closely associated with Dundalk, but this town on Ireland's east coast is turning to less ephemeral kinds of power as it tests technologies to reduce the country's thirst for fossil fuels.

XISHUANGBANNA, China: On a map on the ecologist Liu Wenjie's computer, the subtropical southern tip of Yunnan Province is slowly turning from green to red. Rubber plantations, shown in red on Liu's computer screen, have supplanted nearly all the low-lying forest in the prefecture of Xishuangbanna and are now starting to encroach on the highlands.

SUNNYVALE, California: Call it an eco-parable: one Prius-driving couple takes pride in their eight redwoods, the first of them planted over a decade ago. Their electric-car-driving neighbors take pride in their rooftop solar panels, installed five years after the first trees were planted.

The charged and complex debate over how to slow down global warming has become a lot more complicated. Most of the focus in the past few years has centered on imposing caps on greenhouse gas emissions to prod energy users to conserve or switch to nonpolluting technologies.

Even allowing for the low expectations we bring to any lame duck president's final state of the Union address

U.S. sales for each of the four largest automakers in the United States fell last month, prompting some executives to forecast a gloomy spring, a period that typically posts strong sales. General Motors and Toyota said they were optimistic about the benefits of declining interest rates and tax rebate checks that most Americans will get starting in May as part of the U.S. government's economic stimulus package. Executives at Ford Motor, however, said they did not think the industry had hit bottom yet.