In the news this week...

USAID STUDY TO ASSESS ASIAN WATER RESOURCES

United States Agency for International Development have teamed up with a University Boulder team to carry out a four year study investigating the contribution of snow and glacier melt to water resources supplied by the Himalayas. This report aims to increase our understanding of the snow and glacial input to river discharge which can then be used to predict future variability in river discharge under climate change.Due to the limited data available in the region, USAID will use a combination of remotely sensed data to produce time-series maps of intra-annual snowfall and glacial ice melt (NSIDC, 7th December, 2011). This will be combined with meterological and hydrological data in the region to estimate current relationships between snow and glacier contribution and river discharge that can then be extrapolated to predict future river discharge under differenet warming scenarios.

The findings of this study will be highly beneficial for scientists and policy makers within the regions, potentially highlighting the regions that will be at most risk under climate change allowing mitigation methods to be put in place to reduce water scarcity threat in these areas. The data could also be informed in further development schemes, such as avoiding the development of new irrigation plants in areas that are assessed at being at high risk of reductions in river discharge. As my last post has stated, changes to Himalayan glaciers is anticipated to have substantial intra-annual and longer term impacts on river discharge in the region, however, with studies like this being undertaken, our ability to understand the factors determining these changes and how they may change in the future may allow mitigation measures to be put in place to attempt to reduce their impacts.

Figure 1: Major rivers within the ten countries surrounding the Himalayas with headwaters in the mountain area (Source: NSIDC, 7th December 2011).

ICIMOD RELEASE NEW REPORTS SUGGESTING HIMALAYAN GLACIERS ARE MELTING

Following the retraction of a statement in the Fourth IPCC report that ‘all of the Himalayan glaciers would have melted by 2035’, the IPCC has announced that the most recent conclusions from three ICIMOD reports provide new evidence Himalayan glaciers are melting Compiling data from across the Hindu-Kush Himalaya (HKH) Region, these reports provide the most recent data regarding climate change for the region. However, although these reports are the most comprehensive studies yet, ICIMOD state that further research needs to be carried out (ICIMOD, 4th December, 2011)

The reports:

1) The Status of Glaciers in the Hindu-Kush Himalayan Region.

The first report used remotely sensed data to estimate the current extent and distribution of glaciers within the HKH region. Identifying approximately 54,000 glaciers within the region, the lack of data in the region is underlined as of these only ten have been continously monitored to assess changes in glacial mass. Conclusions from the remotely sensed data showed an overall reduction in glacial mass in the central and eastern Himalayas, with reductions over the last thirty years being 22% and 21% in Bhutan and Nepal respectively.

Although additional research will need to be carried out this comprehensive report provides a baseline that can be used to inform discussions over climate change within the Himalayas and can be used to direct further research in the area.

2) Snow Cover Mapping and Monitoring in the Hindu-Kush Himalayas

This report uses regional monitoring to observe changes in the HKH region over the last decade. It concludes that there has been regional disparities within the mountain chain with snow cover decreasing within the central part of the Himalayas, but monitoring indicating a slight increase within the eastern and western regions.

3) Climate Change in the Region: The State of Current Knowledge..

Reviewing the current literature available under the three broad headings: climate and hydrology; biodiversity and ecosystems; and atmospheric changes. The reports underlines the bias of the limited spatial data within the region, often restricted to areas of easier access at lower elevations. Despite this, the report identifies several conclusions within the region including:

•  More pronouced warming in the winter months than the summer months (A claim supported by Singh et al., (2006) report cited in my last post).
• The average overall warming in the region (around 0.74°C in the last 100years) is greaer than the global average, although the ICIMOD emphasis that this is not evenly distributed across the region.
• The report found that warming was most pronounced in the higher altitudinal regions such as the central Himalayas and the Tibetan Plateau, and related to the second report may partially account for the reduction in snow cover in these regions 

• Significant changes in mountain habitats are beginning to occur with the mountain treeline shifting to higher elevations, and the report suggests that some species at higher elevations may disappear as the ecosystems change.

Overall these three reports represent a significant step in bridging some of the major knowledge gaps present in this region, and highlights the benefits of using remotely sensed data when access is to the study area is limited. These reports also support the growing evidence that changes due to global warming may be exaccerbated in the Himalayan region, and therefore the continuation of studies such as this are highly important.