TODAY’S STUDY: MELTING AND HUMAN LIFE

The community of nations continues to bicker over details while the global average termperature rises and the global climate gets weirder. The recent UN climate summit in Cancun was a triumph of diplomacy and the delegates, who had arrived somberly bearing the burden of last year's disappointing Copenhagen summit, reportedly left with a rising sense of hope that somehow, someday, something substantive can really happen. (See INCHING FORWARD AT CANCUN).

Nevertheless, as the report outlined below demonstrates and the agreement reached in Cancun affirms, adaptation is now as much on the minds of the world community's leaders as is mitigation.

In the U.S., the obstacle to action remains an obstinate coterie of climate change deniers. With images of fires and floods emanating from around the world in 2010, their denial is now laughable. It calls to mind the old joke about the wife who confronts her philandering, fast-talking husband in bed with another woman, only to be met by his "This is not what it looks like, honey. Who are you going to believe, me or your own eyes?"

The sad fact is that leaders around the world have clearly decided there will be no timely change in the familiar wearying ways of fossil fuel burners and greenhouse gas emitters and to therefore believe their own eyes and get ready for divorce from the climate the earth has long known.

High mountain glaciers and climate change; Challenges to human livelihoods and adaptation
Bjørn Petter Kaltenborn, Christian Nellemann and Ingunn Ims Vistnes, December 2010 (United Nations Environment Program)

Think of Pakistan, August 2010. Over six million of those flood refugees remain affected. Over half of the people in the world live in places so threatened as the world average temperature rises and glaciers, especially in Asia, melt. As documented in the report highlighted below, the situation is worsening.

For millennia, rivers fed by glaciers have been sources of life. Their melting therefore warrants more research faster to better understand the vulnerability of exposed peoples. Already, over a hundred million people are impacted by floods yearly. Tens of thousands are dying, health impacts are spreading, and food security and livelihoods are threatened.

The just-closed Cancun UN climate summit included in its draft agreement, for the first time, strategies for adaptation such as those described in this report. It is not a good sign.

Summary

Climate change is causing significant mass loss of glaciers in high mountains worldwide. Although glacier systems show a great amount of inherent complexity and variation, there are clear overall trends indicating global glacier recession, which is likely to accelerate in coming decades. Large gaps remain in our understanding and ability to model accurately the key processes and cause-effect relationships driving glacier response to climate change. In addition, a lot of data on glacier mass changes are not available to the public due to national interests concerning water supply.

Impacts of the shrinkage and disappearance of mountain glaciers include changes in the flow characteristics of glacierfed rivers, glacier lake outburst floods (GLOFs) in the Andes and Asia, and changing flood severity and frequency. GLOFs were observed in Patagonia in 2008 and 2009, in addition to GLOFs in the Himalayas and Andes in the past decades in areas where glaciers are receding. While such GLOFs may immediately endanger lives, infrastructure and power supply, flash floods and particularly large-scale down-river floods pose an ever greater challenge and risk. These floods are caused by extreme events of intense and high-volume monsoons or other types of rains that are often exacerbated by unsustainable land use practices killing several thousand people every year directly, and impacting over 100 million people annually, including through loss of crops and eruption of diseases associated with flooding of sewage or contamination of drinking water supplies.

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The glacial contribution to river flow varies greatly, both annually and within and between catchments. The hydrological significance of glacier runoff also depends on other components of the hydrological cycle, such as precipitation, evapo-transpiration, and groundwater flow. In consequence, the impacts of glacier mass loss will be highly variable both locally and worldwide. Some regions will undoubtedly be affected by water shortage, whereas others are unlikely to be significantly affected by glacial melt. Much detailed work remains to be done to adequately predict regional and local hydrological responses to climate change. Flood risks are expected to increase in some regions, including increased frequencies of GLOFs and weather-related flash floods in both the Hindu Kush Himalayas and in the Andes. Melting of glaciers and ice caps will also have global effects on sea level rise. It is currently estimated that they will contribute approximately 40 to 150 mm (depending upon the greenhouse gas scenario and climate model used) to sea level rise by 2100.

Changes in glacier regimes and runoff from snow and ice, combined with changes in precipitation timing and intensity will most likely increase human vulnerability in many areas. Livelihoods are affected as climate variability and water stress affect agriculture, forestry, health conditions and tourism. Future challenges for the management of impacts of climate change include filling data gaps, improving regional cooperation in observation networks and developing comprehensive databases, improving modeling of glacier mass balance and runoff, strengthening regional cooperation and developing adaptive strategies that are cultural and context specific, and ensuring sufficient irrigation capacity to uphold higher levels of food production.

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One of the chief challenges in the coming decades will be to capture and store excess water during periods of high water availability. We are likely to experience more extreme melting, as well as extreme events of rainfall. With great land-use pressures in many mountain regions, including deforestation and heavy grazing combined with extreme rainfall, flashfloods and flooding will likely increase. New and more effective systems in both capturing and storing water will become essential in the future. This includes both installation of new water capture and storage methods, as well as re-introduction of some of the ancient traditional irrigation systems, such as the qanat, foggara, karez or falaj systems known from desert regions, and the zabo, pokhari, johad and pyne systems known from hilly regions.

Irrespective of the variation in glacial and snow melt, which normally contributes only a smaller share of the total river flow, future variability in timing and intensity of precipitation will contribute substantially to down-river impacts. Indeed, continuing land pressures, rapid urban development and settlement of the impoverished in exposed low-lying areas greatly influence flood risks, health and livelihoods. More than 40% of the world’s floods takes place in Asia, and have affected near a billion people 1999–2008, and causing an estimated 20–25% of all deaths associated with natural disasters. In 2009, more than 56 million people were severely impacted by floods and over 1 million people by the smaller, but often dangerous flash floods.

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Down-river regions also comprise critical food production centres. The combined actions of changes in timing and intensity in monsoons, other precipitation and land use will continue to often over-rule changes in glacial melt for downstream population centres, and provide major impacts not only on drought and flood risk and subsequent human exposure, but also on food security. This is particularly true for the Hindu-Kush Himalayas, Central Asia and parts of the Andes where large populations depend upon the mountains and predictable climate for food production and livelihoods.

Irrigation systems and pipelines from major rivers should also be developed, maintained and improved, also because deforestation frequently increases the rate and speed of the flow of water into major channels. Necessary training, revival of old knowledge and implementation of new greener irrigation technology will require funds and programmes directed towards adaptation. Storing excess water, adapting to floods and developing and implementing more effective irrigation systems will become crucial to future food security in regions dependent upon mountains for their water supply.

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Glacier melt inputs to rivers can affect the ecosystems in a number of ways, including habitat changes such as stream temperatures, sediment concentrations, water chemistry and nutrient availability, or through the release of pollutants deposited and stored in the glaciers over many years, impacting fish and other organisms in glacier-fed systems.

Adaptation, mitigation and development should be seen as a continuum. Livelihood diversification will require significant policy and institutional support, and strategies must be sensitive to cultural contexts, norms and differences. Good governance and planning need to take climate change into account in order for infrastructure development to support water security.

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Recommendations:

• Strengthen glacial research and trans-national collaboration with emphasis on mass calculation, monitoring and particularly the effects of glacial recession on water resources, biodiversity and availability downstream.

• Improve modeling on precipitation patterns and effects on water availability in particular in mountain regions of Asia and Latin America.

• Prioritize support to and development of adaptation to water-related disasters.

• Prioritize programmes and support to development and implementation of adaptation strategies for too much and too little water including strengthening the role of women.

• Urgently support the implementation and improvement of both small and large-scale water capture and storage systems and improve efficiency of current irrigation systems through the use of green technology and agricultural knowledge.

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Introduction

There is increasing concern about impacts of climate change on high mountain glaciers and snow ablation, and the effects of glacier recession on sea-level rise, natural hazards and water resources. The conference “High mountain glaciers and challenges caused by climate change” was held in Tromsø on 8–10 June 2009, initiated by the Norwegian Ministry of the Environment in cooperation with the United Nations Environmental Programme (UNEP), and hosted by the Norwegian Polar Institute. The conference gathered leading scientists from glaciology, geography, resource management and related fields to discuss the latest research on high-mountain glacier meltings and the consequent effects on downstream regions.

This report presents an update based on presentations and working group discussions at the conference, combined with recent compilations on issues of food security, disaster management and the need for adaptation, including from the Himalayas Climate Impact Assessment pilot study (ICIMODa-b, 2009; UNEP, 2009; 2010b). It outlines status and trends of high mountain glaciers in relation to climate change, identifies challenges and knowledge gaps, and finally makes recommendations for adaptation, research and policy.

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Impacts of climate change on glaciers, snow and ice in high mountain regions

The majority of mountain glaciers are losing mass in response to climate change. Most glaciers have been shrinking since the end of the Little Ice Age around 150 years ago. However, since the beginning of the 1980s the rate of ice loss increased substantially in many regions, concurrent with an increase in global mean air temperatures. Glaciers might disappear from some mountain regions by the end of the 21st century given the current melting rate. At the same time, some glaciers have increased in size since the 1980s. This is consistent with regionally increased precipitation in a warming world.

Downstream impacts of changing glaciers, snow and ice; The importance of glaciers for freshwater supply to downstream populations

Glacier melt contributes to river flow in many parts of the world, so changes in glacier mass can affect the availability of freshwater supply at diurnal, seasonal and multi-annual timescales. The importance of the glacial contribution to runoff depends on the magnitude of other components of the hydrological cycle, and is thus regionally highly variable.

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Glacier Lake Outburst Floods (GLOFs)

In mountain regions, potentially unstable lakes can form when advancing glaciers block drainage routes, or when basins open up between retreating glaciers and abandoned terminal moraines. Glacier lake outburst floods (GLOFs) have caused loss of life, and loss of agricultural land and infrastructure. There is some indication that the frequency of GLOFs has increased due to climate change, and the impacts of GLOFs are very likely to increase in the coming decades as glacier retreat continues. GLOFs can have a very large impact locally, but the number of people affected by potential GLOFs is far less than those impacted by other types of floods.

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Flash floods

Flash floods are common to most mountain areas and a continuous challenge to water resources management and disaster reduction management in particular. They represent some of the most devastating types of floods due to rapid occurrences, large quantities of water, high sediment content and fast moving flood waves. They are a typical feature of steep topography where the land has limited retentive capacity in areas with high variability in rainfall, such as in monsoon regions.

Challenges ahead…Data availability and accessibility… Modelling water flow is complicated

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Mitigation and adaptation to climate change and water stress

People living in mountain regions across the world are used to environmental change and are regularly dealing with too much or too little water, both conditions often occurring within the same season or within short periods of time. Hence many mountain peoples have developed a series of strategies for dealing with a dynamic environment and have considerable adaptive capacity. For instance, many Himalayan farmers are now increasing food and water storage capacities to better prepare for floods and droughts (Dekens and Eriksson 2009). However, most mountain regions are now experiencing greater ranges and rates of change, that likely will stress and in many cases exceed the adaptive capacities of the social-ecological systems.