1f:T45a,Collectively, reservoirs created by dams are thought to be an important source of greenhouse gases (GHGs) to the atmosphere. So far, efforts to quantify, model, and manage these emissions have been limited by data availability and inconsistencies in methodological approach. Here, we synthesize reservoir CH₄, CO₂, and N₂O emission data with three main objectives: (1) to generate a global estimate of GHG emissions from reservoirs, (2) to identify the best predictors of these emissions, and (3) to consider the effect of methodology on emission estimates. We estimate that GHG emissions from reservoir water surfaces account for 0.8 (0.5-1.2) Pg CO₂ equivalents per year, with the majority of this forcing due to CH₄. We then discuss the potential for several alternative pathways such as dam degassing and downstream emissions to contribute significantly to overall emissions. Although prior studies have linked reservoir GHG emissions to reservoir age and latitude, we find that factors related to reservoir productivity are better predictors of emission.20:T495,Abstract A GIS‐based RUSLE model is employed to study the global soil erosion potential for viewing the present situation, analysing changes over the past century, and projecting future trends with reference to global changes in land use and climate. Scenarios considered in the study include historical, present and future conditions of cropland and climate. This research gives the first overview of the global situation of soil erosion potential considering the previous century as well as the present and future. Present soil erosion potential is estimated to be about 0·38 mm year −1 for the globe, with Southeast Asia found to be the most seriously affected region in the world. It is estimated that nearly 60% of present soil erosions are induced by human activity. With development of cropland in the last century, soil erosion potential is estimated to have increased by about 17%. Global warming might significantly increase the potential for soil erosion, and the regions with the same increasing trend of precipitation and population might face much more serious problems related to soil erosion in the future. Copyright © 2003 John Wiley & Sons, Ltd.

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