28 Nov 2007 | slide 1

Regional impacts and vulnerability – mountain areas

1st EIONET workshop on climate change vulnerability, impacts and adaptation

EEA, Copenhagen, 27-28 Nov 2007

Klaus Radunsky

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Overview

Fourth Assessment Report of the IPCC Other sources of information

OECD, UNFCCC – Nairobi Work Programme, regional work shops Activities in EU-MS Activities in Austria

Conclusions

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AR4 of the IPCC (1)

No specific chapter on mountain areas in WG II Report although mountain regions cover worldwide circa 20-24% of all land; support many different ecosystems with very high species

richness; have a significant role in biospheric carbon storage (28% of

forests are in mountains) and carbon sequestration; have a significant role in water purification and climate

regulation beyond their geographical boundaries in all continents;

allow habitability, e.g. through slope stabilisation and protection from natural disasters;

serve as refuges for many endemic species; provide many goods for subsistence livelihoods, and are

attractive for recreational activities and tourism;

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AR4 of the IPCC (2)

WG II Technical Summary: limitations on mountain sports in lower-elevation alpine

areas (high confidence); Mountain ecosystems most vulnerable and will experience

the most severe ecological impacts, including species extinctions and major biome changes;

species loss likely affecting many plants and animals (high confidence); changes are already detected in mountain ecosystems (up to a 60% loss of species under high-emissions scenarios by 2080);

Increase in frequency of rockfalls due to destabilisation of mountain walls by rising temperatures and melting of permafrost;

Winter tourism in mountain regions faces reduced snow cover (duration of snow cover to decrease by several weeks for each °C of temperature increase);

redistribution of tree species, and elevation of the mountain tree line. Increase of forest-fire risk (especially in southern Europe).

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AR4 of the IPCC (3)

WG II – Chapter 1: Assessment of observed changes and responses in natural and managed systems

enlargement of glacial lakes in mountain regions and destabilisation of moraines damming these lakes;

Glaciers and permafrost: Receding of mountain glaciers globally (larger than at any time over at

least the last 5,000 years); probably induced by anthropogenic warming;

Thawing of permafrost in the Northern Hemisphere

Elevational shift, increased species-richness on mountain tops;

adaptation in the Arctic and mountain regions includes reduced outdoor and tourism activities

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AR4 IPCC (4)

Glaciers, details:

Changes in mountain glaciers and ice caps effected runoff, changed hazard conditions and ocean freshening;

enhanced melting of glaciers leads at first to increased river runoff and discharge peaks and an increased melt season, while in the longer time-frame (decadal to century scale), glacier wasting should be amplified by positive feedback mechanisms and glacier runoff is expected to decrease.

emerging evidence of crustal uplift in response to recent glacier melting; records preserved in the firn and ice layers are destroyed due to

percolation of melt water and mixing of chemical species and stable isotopes.

formation of large lakes is occurring as glaciers retreat; Thawing of buried ice destabilizing the Little Ice Age moraines. Lakes with

high potential for glacial lake outburst floods (GLOFs). Enhanced colonization of plants and animals in deglaciated terrain; striking changes in the landscape, affecting living conditions and local

tourism. Emergence of slope instability and rock falls, including outburst floods.

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AR4 IPCC (5) No mentioning of “mountains” in chapter 3 (fresh water

resources and their management) Chapter 4: Ecosystems, their properties, goods and services

significant forest dieback towards the end of this century and beyond shown by most DGVM models based on A2 emissions scenarios in tropical, boreal and mountain areas, with a concomitant loss of key services;

Mountain forests are increasingly encroached upon from adjacent lowlands, while simultaneously losing high-altitude habitats due to warming;

mountain regions have experienced above-average warming in the 20th century, a trend likely to continue;

reshuffling of species on altitude gradients as a consequence of individualistic species responses; mediated by varying longevities and survival rates.

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AR4 – IPCC (6)

Chapter 4: Ecosystems, their properties, goods and services

in the interior of mountain ranges projected forest dieback due to increased drought in case of warmer and drier conditions;

mountain species are disproportionately sensitive to climate change (about 60% species loss); human pressures on mountain biota can further increase species loss;

Substantial loss of alpine zone, and its associated flora and fauna (e.g., alpine sky lily and mountain pygmy possum) reported for Australia (T increase 3.3 degrees C above pre-industrial level);

Rivers fed by mountain springs and glaciers transport water and nutrients from the land to the oceans and provide crucial buffering capacity during drought;

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AR4 – IPCC (7)

No mentioning of mountains in the context of chapters 5 (Food, fibre and forest products) and 6 (Coastal Systems and Low-Lying Areas)

Chapter 7 (Industry, settlement and society) energy cost savings in mountain areas needing space-heating during the winter

Chapter 8 (Human health) water insecurity in some regions due to long term reduction in annual glacier snow

melt significant impacts on water supply for communities relying on freshwater runoff

due to changes in the depth of mountain snowpacks and glaciers, and changes in their seasonal melting, (in China, 23% of the population live in the western regions where glacial melt provides the principal dry season water source);

vector-borne pathogens could take advantage of new habitats at altitudes that were formerly unsuitable;

diarrhoeal diseases could become more prevalent with changes in freshwater quality and availability.

increase the number of floods and landslides due to more extreme rainfall events; Increase in morbidity and mortality due to higher risk of glacier lake outburst floods;

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AR4 – IPCC (8) No mentioning of “mountains” in chapters 9 (Africa), 10 (Asia) Chapter 11 (Australia and New Zealand)

Flows in New Zealand’s larger mountain-fed rivers are likely to increase, benefiting hydroelectricity generation and irrigation supply.

Chapter 12 (Europe) European mountain flora will undergo major changes due to climate change; mountain ecosystems among the most threatened in Europe due to risk of loss of

endemism due to invasive species; similar extreme impacts are expected for habitat and animal diversity;

It may be possible to preserve many alpine species in managed gardens at high elevation;

Specific management strategies have yet to be defined for mountain forests. artificial snowmaking already common practice; however, economic only in the

short term, or in the case of very high elevation resorts; may be ecologically undesirable.

Key uncertainties and research needs: Enhancement of climate change impact assessment in areas with little or no previous investigation, e.g., flow regimes of mountain rivers;

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AR4 – IPCC (9)

Chapter 13 (Latin America) Conservation of biodiversity and maintenance of ecosystem structure

and function important for climate-change adaptation strategies, due to the protection of genetically diverse populations and species-rich ecosystems (also practiced for forests – financial incentives);

Chapter 14 (North America) Streamflow in the eastern U.S. has increased 25% in the last 60 years,

but over the last century has decreased by about 2%/decade in the central Rocky Mountain region;

Less mountain snowpack and summer runoff will result in problems in water supply; e.g. for southern California and Vancouver;

additional conservation and water restrictions, expansion of reservoirs, development of additional water sources might be needed;

Relationships between tree-ring growth in sub-alpine forests and climate in the Pacific Northwest from 1895 to 1991 showed complex topographic influences; (indication of growing season temperature limitations on some sites and water limitations on other sites).

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AR4 – IPCC (10)

Practically no mentioning of “mountains” in chapters 15 (Polar regions), 16 (Small Islands), 17 (Adaptation Practices) and 18 (inter-relationships between adaptation and mitigation)

Chapter 19 (Key vulnerabilities) Inter-tropical mountain glaciers and impacts on high-mountain

communities because of their accelerated reduction and melting. Some of these systems will disappear in the next few decades causing flooding in some areas; shifts in ecosystems are likely to cause water security problems due to decreased storage;

Greater risk of dam burst in glacial mountain lakes; risk-reducing potential very limited or very costly for some key

vulnerabilities such as melting of mountain glaciers and loss of biodiversity;

Importance of a vulnerable system: if the livelihoods of many people depend crucially on the functioning of a system, this system may be regarded as more important than a similar system in an isolated area (e.g., a mountain snowpack system with large downstream use of the melt water versus an equally large snowpack system with only a small population downstream using the melt water).

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Conclusions

Mountain areas can be highly vulnerable to climate change

Risk-reducing potential of planned adaptation is either very limited or very costly

Key uncertainties relating to climate change impact assessment of flow regimes of mountain rivers

European mountains will undergo major changes due to climate change

It is suggested to have a specific focus on mountain areas and their role in preparing climate change impact assessments