Nature has dealt staggering blows to the Earth and its people in 1999: killer landslides in Venezuela and Mexico, devastating earthquakes in Turkey and Taiwan, massive floods along the East Coast of the United States. But these were not the worst disasters of the century, either in the power of the events or in the loss of life and property that they caused, according to a U.S. Geological Survey of the century's worst landslides, earthquakes, volcanoes, and floods. (U.S. Geological Survey release)

As though there weren't enough global concerns about the Y2K problem, yet another possible problem could occur on that historic transition in time: a geomagnetic storm. While it is geomagnetic storms that give rise to the beautiful Northern lights, they can also pose a serious threat for commercial and military satellite operators, power companies, and astronauts. The Earth's magnetic field can undergo large and rapid fluctuations due to the interaction of charged particles ejected by the Sun that collide with the geomagnetic field. These solar ejections are associated with sunspots, whose number increase and decrease over an 11-year cycle. The next peak in sunspot activity - and the resulted geomagnetic storms - is expected to occur in early 2000. (U.S. Geological Survey release)

A growing body of evidence indicates that a climate phenomenon called the Arctic Oscillation has wide-ranging effects in the Northern Hemisphere and operates differently from other known climate cycles. The evidence indicates the acceleration of a counterclockwise spinning ring of air around the polar region could be responsible for warmer winters in Scandinavia and Siberia, thinning of the stratospheric ozone layer, and significant changes in surface winds that might have contributed to Arctic ice thinning. (University of Washington release)

Rainfall patterns in the Amazon change when humans alter the land during deforestation and farming, causing some areas to suffer drought while other areas succumb to floods. Now, Rong Fu of Georgia Institute of Technology has found that the ocean surface temperature in the Atlantic and the Pacific surrounding South America has as much of an impact on rainfall as land cover changes do, helping scientists see the human effect on rainfall patterns and helping predict impending drought or floods. (Georgia Institute of Technology release)

The environmental effects of tiny atmospheric particles, known as aerosols, are of growing concern. Aerosols are now thought to significantly affect Earth's energy balance, throwing a wrinkle in climate-change forecasts. At a recent meeting on the subject, researchers concluded that accurate quantification of aerosols' effects will require combining remote techniques that can survey vast regions of the atmosphere with local techniques that can provide detailed information on particle characteristics. (University of Illinois at Urbana-Champaign release)

The United States and countries in and bordering the Caribbean Basin should experience fewer storms and hurricanes in 2000 than in recent years, according to the Colorado State University hurricane forecast team's initial prediction. William Gray, a nationally recognized hurricane expert, and his colleagues are calling for a "moderate" season in 2000 with 11 named storms, seven hurricanes and three intense hurricanes predicted. (Colorado State University release)

A new study suggests that cleaning up the air may help to feed the world. Published in the Proceedings of the National Academy of Sciences, the NASA-funded study found that heavy regional haze in China's most important agricultural areas may be cutting food production there by as much as one-third. Covering a million square kilometers or more, the haze scatters and absorbs solar radiation, reducing the amount of sunlight reaching key rice and winter wheat crops. "In China there is a significant amount of haze that reduces the sunlight reaching the surface by at least 5 percent, and perhaps as much as 30 percent," said William L. Chameides of the Georgia Institute of Technology. "The optimal yields of crops in China are likely reduced by the same percentage." (Georgia Institute of Technology release)