Understanding the Long-Term variability of Lake Chad environments: a paleoclimate modelling approach for a better assessment of future changes
The anthropogenic global warming affects not only surface air temperatures, but also the hydrological cycle. While high latitudes are more vulnerable to temperature increases, low latitudes are the most sensitive to changes of the hydrological cycle. One notorious weakness of climate models involved in the IPCC climate projections is embedded in the future evolution of the low-latitudes precipitation patterns. These uncertainties pose a major challenge to the climate models ability to provide a reliable diagnostic on the vulnerability and adaptation of societies.
One extremely variable and vulnerable resource is the Lake Chad located in the core of the sahelian area, onto which resources 13 million people directly depend (crop culture, farming and fishing activities). We aim to investigate in detail the vulnerability of Lake Chad region with respect to the changes in the regional hydrological cycle as anticipated by climate models. To do this, we will use a suite of models and downscaling techniques which are designed to document the connections between global and regional climate changes, including vegetation and hydrological models, to diagnose how the regional precipitation changes will affect water resources in this region. Considering the uncertainty of precipitation predictions for the future in this region, we will investigate the Lake Chad variability during past warm periods which can be considered as analogues of the future global warming in this region.