Solicited speaker: X-C John Zhang, USDA Agricultural Research Service (US)

Recent research has shown that global climate change may significantly change the driving forces behind soil erosion. However, the relationship between climate change and soil erosion is non-linear and involves changes in multiple, and often interlinked, driving forces, both promoting and reducing erosion rates.

Some impacts of climate change on erosion are direct; rainfall increases in the mid to high latitudes, equatorial regions and the south-east Asian monsoon region could lead to higher runoff and erosion rates. Furthermore, a global acceleration of the hydrological cycle could lead to a concentration of rainfall in more intense storms, increasing rainfall erosiveness even where the total rainfall is lower. Other impacts could come from climate-induced changes to vegetation cover, agricultural management practices and land use patterns. For example, lower rainfall could lead to increased aridity, reducing vegetation cover and exposing the soil to erosive forces. Other examples of potential impacts include changes on soil structure and erodibility, permafrost thawing, spatial and temporal soil moisture patterns, or the frequency of vegetation disturbances (e.g. severe droughts and wildfires), all of which could have large impacts on erosion rates.

There are also links and feedbacks between these processes which should be considered when estimating impacts of climate change on erosion rates. Soil erosion, vegetation cover and land-use patterns may depend on and reinforce each other, especially in regions with degraded soils. Climate change could alter these patterns and lead to significant shifts of land use, vegetation cover and erosion rates, e.g. where desertification thresholds are surpassed, which could contribute to enhance the impacts of climate change in vulnerable regions. Finally, prediction is further complicated by the influence of socio-economic drivers on land-use patterns and intensity, and by potential links and feedbacks between soil erosion and climate change (through the water and carbon cycle) which have so far received little attention in this field.

So far, these issues have only partially been taken into account in studies assessing the impact of climate change on soil erosion. These limitations need to be addressed before the results from localized studies can be upscaled to the regional and global scale, general conclusions can be extrapolated, and appropriate soil conservation measures can be developed and assessed.

The purpose of this session is to join together scientists doing research on climate change and impacts on soil erosion, to share ideas, methodologies and results and contribute to improve climate change assessment methods. This session invites contributions detailing studies of direct and indirect impacts of climate change on soil erosion. Welcomed topics include:
- studies of the impacts on climate change on soil erosion (including gully erosion) and catchment sediment yield;
- assessments of the impacts of climate change on erosion drivers;
- comparative studies of soil erosion processes and drivers across climatic transects, with implications for climate change impacts;
- links and feedbacks between erosion, vegetation cover and land-use change under future climate scenarios;
- impacts of soil erosion on climate;
- land use and management responses to climate change and impacts on soil erosion;
- adaptation of land conservation practices and policies to climate change;
- uncertainties associated with erosion prediction for future climate scenarios.

Especially welcome are studies which cross spatial and temporal scales, focus on the combination of different types of climate change impacts, extrapolate results for large areas, or focus on the lower or higher latitudes.