Climate Change In Himalaya

Literature Review

Climate change and Himalayas

Himalayas are one of the most important part of ecosystem of earth as they feed many rivers in Asia with around 3 billion people living in different catchments of these rivers. Glaciers of Himalayas contain a major part of earth’s water stored in form of ice which if melts due to temperature increase can cause a huge impact on living organisms. Hence, understanding the climate of Himalayas is very crucial.

Significant changes in temperature, rainfall, and vegetation phenology across the Himalayas was reported by analyzing the temperature, precipitation and NDVI (Normalized Difference Vegetation Index) between 1982 and 2006 (Shrestha et al. 2012). They observed 1.5°C increase in annual average

(2003) carried out a study on Normalized difference Vegetation Index (NDVI) and meteorological data over part of Sahelian Africa and Europe over several years. The vegetation dynamics were quantified as the total amount of vegetation (mean NDVI) and the seasonal difference (annual NDVI amplitude) by a time series analysis of NDVI satellite images with the Harmonic Analysis of Time Series algorithm. A climate indicator (CI) was created from meteorological data (precipitation over net radiation). The relationships between the vegetation dynamics and the CI are determined spatially and temporally. The driest areas prove to be the most sensitive to climate impact. However, they could not whether the impact is same everywhere on earth due to limitation on

(2003) explore natural and anthropogenic influences on the climate system, with an emphasis on the biogeophysical and biogeochemical effects of historical land cover change. The biogeophysical effect of land cover change was first subjected to a detailed sensitivity analysis in the context of the UVic Earth System Climate Model. Results showed a global cooling in the range of –0.06 to –0.22 °C, though this effect was not found to be detectable in observed temperature trends. They then include the effects of natural forcings (volcanic aerosols, solar insolation variability and orbital changes) and other anthropogenic forcings (greenhouse gases and sulfate aerosols). Transient model runs from the year 1700 to 2000 were presented for each forcing individually as well as for combinations of forcings. They found that the UVic Model reproduces the global temperature data well when all forcings are included. These transient experiments were repeated using a dynamic vegetation model coupled interactively to the UVic Model. They found that dynamic vegetation acts as a positive feedback in the climate system for both the all-forcings and land cover change only model runs. Finally, the biogeochemical effect of land cover change was explored using a dynamically coupled inorganic ocean and terrestrial carbon cycle model. The carbon emissions from land cover change were found to enhance global temperatures by an amount that exceeds the biogeophysical cooling. The net