Scientists studying variations in tropical heat and rainfall since the mid-1980s have found a strong link between warm periods and more extreme downpours.

The observed rise in the heaviest rains is about twice that produced by computer simulations used to assess human-caused global warming, said the researchers.

Other studies have already measured a rise in heavy rains in areas as varied as North America and India, and climatologists have long forecast more heavy rains in a world warmed by accumulating greenhouse gases.

A grueling survey of vast tracts of forest and swamp in the northern Congo Republic has revealed the presence of more than 125,000 western lowland gorillas, a rare example of abundance in a world of rapidly vanishing primate populations.

As recently as last year, this subspecies of the world's largest primate was listed as critically endangered by international wildlife organizations because known populations - estimated at less than 100,000 in the 1980s - had been devastated by hunting and outbreaks of Ebola virus. The three other subspecies are critically endangered or endangered.

The rise in concentrations of carbon dioxide in the atmosphere from human activities is influencing climate patterns and vegetation across the United States and will significantly disrupt water supplies, agriculture, forestry and ecosystems for decades, a new U.S. government report says.

After decades of research that sought, and found, evidence of a human influence on the earth's climate, climatologists are beginning to shift to a new and similarly daunting enterprise: creating decade-long forecasts for climate, just as meteorologists routinely generate weeklong forecasts for weather. One of the first attempts to look ahead a decade, using computer simulations and measurements of ocean temperatures, predicts a slight cooling of Europe and North America, probably related to shifting currents and patterns in the oceans.

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.

Elected leaders in New York City will propose a suite of laws and other initiatives on Wednesday aimed at reducing energy consumption and related emissions of greenhouse gases by requiring owners of thousands of older buildings to upgrade everything from boilers to light bulbs.