Climate change in the Hindu Kush-Himalayas -The state of current knowledge - A book by ICIMOD

The Hindu Kush-Himalayan region has had very few resources to develop a detail scientific understanding needed to assess climatological, environmental, and other data in the past and there is very little information upon which a baseline for comparison with the present can be formed and future impacts can be anticipated. However, many changes have taken place in the last decade and capacities in the region have improved. Thus, data are now more easily sorted and shared, and available for understanding the changes occuring due to climate change in the region.

The analysis of available data from the region indicates that:

There is scant evidence available on climate trends, glacial melting and hydrology in the region

Hydrometeorological data for the HKH region are scarce and the region overall has far too few weather stations because of the difficulties presented by extreme variations in altitude and aspect. The data that are available indicate that there is a moderate warming trend and that temperature increases are more pronounced at higher than at lower elevations.

The data on precipitation are even scarcer and do not show any statistically significant trend. In view of the paucity of observational data, global climate models are downscaled to the region to help predict trends. Models for the region generally predict increasing temperatures and greater amounts of precipitation than at present to the middle of the century.

The ruggedness and inaccessibility of the region renders the study of glaciers difficult and repeat measurements are rare. To date, less than a few dozen glaciers have been observed and documented at close range. Contributions to river flows continue to be poorly studied; there are few data on river hydrology that indicate either an increasing or decreasing trend in river flows; and models that predict river flows are also inconclusive.

Information on the effects of climate change on biodiversity are still unclear

The HKH region is home to some of the richest and most varied ecosystems on the planet. Changes in climate and the consequent changes in the availability of water can be expected to be reflected in the biodiversity of these ecosystems. To date, however, it is still unclear how the biodiversity has been affected by climate change since the necessary baseline data are not available. The identification and recording of species is still in its early stages and the constant monitoring needed to examine population dynamics as a function of changing climate impacts is lacking.

The impact of atmospheric pollutants (black carbon) on the climate are unknown

In the HKH region, climate change is exacerbated by atmospheric pollution that originates in the plains and is transported to the high Himalayas as a ‘black cloud’. These tiny particles of black carbon warm the ambient air, and when they are deposited on ice and snow they accelerate melting by lowering the albedo. The extent to which these atmospheric pollutants are capable of altering circulation and precipitation patterns, and the extent to which they accelerate the melting of ice and snow remains unknown.

The impact of climate change on livelihoods in the region remain unclear

Although it is certain that climate change will affect the availability of water and biodiversity and food security, the manner in which these changes will occur can so far only be inferred. Since trends are still unclear, the extent to which changes can be attributed to climate variations alone (amid a matrix of other drivers of change) is difficult to determine

The positive and negative impact of climate change on human health in the region remain unknown

The rising temperatures and erratic weather patterns that are the hallmark of climate change will interfere with water supplies, facilitate the spread of infectious diseases, and increase the frequency of natural hazards and disasters. Predictions based on models show that the impacts on both human life and ecosystems can be both positive and negative.

The need to devise strategies for climate resilient development in the face of uncertainty

The ecosystems of the HKH are extremely vulnerable to both growing anthropogenic changes and the consequences of climate change. The need for suitable strategies for climate resilient development has policy and governance implications. The gaps and scientific uncertainties that surround climate change in the HKH region need to be prioritised and addressed strategically. Ecosystem resilience, green sector mitigation, and adaptation to climate change are areas that should be strengthened through policy advocacy supported by evidence from rigorous research and verified information.

This book concludes by discussing how existing knowledge and data gaps need to be filled by systematic observations and enhanced capacities for research in the region and by discussing climate change frameworks for linking efforts both regionally and globally. It considers relevant policies for the region and for national governance, as well as the challenges and the opportunities that can arise from climate change.

A copy of the book can be accessed from this link