Impact of urban expansion on continental- to regional-scale warming

Although the influence of land use/land cover change on climate has become increasingly apparent, cities and other built-up areas are usually ignored when estimating large-scale historical climate change or for future projections since cities cover a small fraction of the terrestrial land surface1,2. As such, ground-based observations of urban near-surface meteorology are rare and most earth system models do not represent historical or future urban land cover3–7. Here, by combining global satellite observations of land surface temperature with historical estimates of built-up area, we demonstrate that the urban temperature signal on continental- to regional-scale warming has become non-negligible, especially for rapidly urbanizing regions in Asia. Consequently, expected urban expansion over the next century suggest further increased urban influence on surface climate under all future climate scenarios. Based on these results, we argue that, in line with other forms of land use/land cover change, urbanization should be explicitly included in future climate change assessments. This would require extensive model development to incorporate urban extent and biophysics in current-generation earth system models to quantify potential urban feedbacks on the climate system at multiple scales.

Impact of Land Use Land Cover Change on Sambhar Lake

The Aravalli range is one of the oldest mountain ranges in the world. Many lakes are sustained by the streams generated from the Aravalli range. In the last few years, hill systems are facing changes affecting the catchment of water bodies. Many waterbodies that were earlier able to provide water in peak summers are now dried up before the summer. The study aims to analyse land use land cover change in the Aravalli range on Sambhar Lake. Sambhar Lake is the largest inland saltwater lake in India and was selected as a “Ramsar Site.” A catchment area of the lake is delineated, and micro-watersheds are selected for detailed analysis. A primary survey is done to know the impacts and causes of changes in the lake. The study indicates significant green cover changes in three seasons over the years. Because of the loss in green cover, the soil is losing its moisture, affecting the cropping pattern and agriculture production in the area. Factors causing the drying of the lake are affecting its ecosystem and the number of birds coming to it.