Tiempo Climate Cyberlibrary

Climate Vulnerability and Adaptation in Nepal

	Anil Raut presents a summary of the climate change impacts confronting Nepal and discusses adaptation measures that are being undertaken.
The author is working on climate change issues with Winrock International, Nepal. He has worked in the past as a researcher with EnvironmentNEPAL.

The climate of Nepal varies from arctic to tropical within a 200km span from north to south. This variability of climatic conditions within a short distance and limited area has blessed this beautiful mountainous country with a high diversity of flora and fauna as well as a plentiful supply of water resources.

Nepal has nearly 4.5 per cent of the world's mammalian species and over nine per cent of bird species. The immense bio-climatic diversity in Nepal supports more than thirty- five forest types giving rise to 5,833 species of flowering plants, including around 248 species of endemic plant and 700 species of medicinal plants. Nepal's landmass is also home to 185 species of mammals, 847 species of birds, 645 species of butterflies, 170 species of fishes and other animals. At this time, 26 species of mammals, nine species of birds and three species of reptiles are declared endangered.

Nepal has a negligible share in global emissions of greenhouse gases. This, together with the fact that its fragile mountain ecosystem is particularly vulnerable to climate change, is why Nepal needs to focus on adaptation measures rather than those of mitigation.

Nepal's major natural resources, biodiversity and water, are at the forefront of climate vulnerability. Analysis of mean monthly river discharges, for example, shows that global warming would melt snow cover on the mountain tops earlier, thus shifting the peak discharge month from August to July. This could lead to increased flooding as well as more pronounced variations in water availability throughout the year.

There are a number of sectors in which climate change impacts on water resources will affect Nepal. These include natural disasters, hydropower, irrigation, and domestic water usage. Of these, it is the potential increase in climate-related disasters, particularly from glacial lake outburst floods, that is perhaps the most prevalent threat.

The formation and growth of glacial lakes is closely related to deglaciation. Valley glaciers usually contain a supra-glacial pond which can substantially increase in size through the melting of glaciers and any warming in climate. The moraine walls that act as dams are structurally weak and unstable. Growing pressure on this natural dam can lead to catastrophe through glacial lake outburst floods.

Out of 2,323 glacial lakes in Nepal, twenty lakes have been found to be potentially dangerous because of the apparent potential for glacial lake outburst floods. The most significant such event, in terms of recorded damage, occurred on August 4th 1985. A glacial lake outburst flood caused a ten to fifteen metre high surge of water and debris to flood down the Bhote Koshi and Dudh Koshi rivers for ninety kilometres destroying, amongst many things, the Namche Small Hydro Project.

Climate also plays a major role in determining the feasibility of hydropower projects. Potential changes in precipitation and temperature that are likely to affect runoff must always be taken into account. Both the Bhote Koshi and the Dudh Koshi rivers have their headwaters high in the Himalayas. Nepal has the potential to generate around 43,000 megawatts of hydroelectricity taking account of the contribution of all the country's rivers. But if a river's discharge is always unpredictable there will continually be problems and failure in any design of hydropower plants. Not only will there be problems in designing hydropower plants to account for a highly variable water supply, but extreme events such as glacial lake outburst floods will also physically damage or destroy the power plants.

As 80 per cent of the Nepalese population depends on agriculture, any changes in climatic conditions affecting rainfall patterns will have an adverse impact on the livelihoods of most of the Nepalese people, which means that there is always the high risk of food insecurity.

The majority of the population is directly dependent on a few crops such as rice, maize, and wheat. Most of the farmers are reliant on rainwater for irrigation as the country lacks major facilities for artificial irrigation. Farmers, therefore, prepare their cropping calendar according to the experience they have with both the intensity and the time of rainfall. Any significant changes to this pattern will lead to loss in crop yield.

There is a clear need to educate the farmers on the possible effects of climate change, particularly in regard to changing rainfall patterns. A cropping technique for rice such as the System of Rice Intensification, together with crop diversification, is one important alternative that should be promoted, requiring less irrigation than conventional farming practice. The government also needs to provide assistance to farmers in establishing alternate means of irrigation.

Vegetation patterns would also be altered by changes in temperature and precipitation. This, in turn, would affect biodiversity. Vegetation patterns and distribution would be different under any changed climatic scenario. Not only would the diversity of plants be affected but also the animals which live within a particular habitat.

Increased disasters, particularly from floods related to glacier melt, would directly impact on human health. Diseases such as malaria and Japanese encephalitis may also increase their impact through expanding to new regions. One area that would be at risk of an increase in diseases is the lower flat plain of Nepal, the Terai region, which is warmer than the mountain regions. The current lack of primary healthcare for large portions of the population also contributes to their vulnerability. Future climate change and the possible impact on human health needs to be considered now and national support, education and comprehensive coping strategies should be initiated through the establishment of widespread primary healthcare centres.

As a response to the increasing awareness of Nepal's vulnerability to climate change, numerous adaptation options for various sectors have been proposed and many already implemented.

One major project that focuses on glacial lake outburst flood mitigation has been undertaken in the Tsho Rolpa glacial lake area. With the support of The Netherlands, the Nepalese government undertook a project to drain and reduce the depth of the Tsho Rolpa glacial lake by three metres. This reduced the risk of a glacial lake outburst flood by twenty per cent. A major aspect of the design was that a channel was cut into the moraine, and a gate was constructed to allow water to be released as necessary.

For other potential glacial lake outburst flood sites, an early warning system has been proposed for the people living downstream. In conjunction with an engineering project that was undertaken between 1998 and 2002 to reduce the risk of a glacial lake outburst flood occurring on Tsho Rolpa, an early warning system was simultaneously established in nineteen villages downstream of the Rolwaling river. Local villagers have been actively involved in the design of this system to ensure that they feel safe from the potential glacial lake outburst flood event and at the same time be aware about the potential damage.

Certain glacial lake outburst flood mitigation measures can provide additional benefits. For example, micro-hydropower and drained off water could also be used to supplement dry season flows. This strategy could also help to maintain adequate water levels in downstream ecosystems to protect valuable fish stocks and in the supply of water for local usage.

It is too soon to comment on the results of any government action on these adaptation measures. At the moment, one important activity that needs to be urgently focused on is the identification of the nation's vulnerable sites and sectors and proposals need to be devised for appropriate adaptation measures. Civil society in Nepal must also play its part in finding ways to integrate adaptation to the possible impacts of climate change with the current development process.

Disclaimer
The views expressed in this article are those of the author and do not explicitly represent those of the author's affiliated organization.

Further information
Anil K Raut, PO Box 12362, Kathmandu, Nepal. Email: araut@winrock.org.np or ankraut@wlink.com.np. Web: www.winrock.org.np.

On the Web
Nepal's Initial National Communication under the UNFCCC is available as a 2.8Mb download. The Tiempo Climate Cyberlibrary presents a listing of theme sites on mountains and climate change.