Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download - Arctic Portal Library
Document related concepts
no text concepts found
Transcript
Can we imagine a World without Ice? Climate change: Impacts on glaciers Helgi Björnsson Institute of Earth Sciences, University of Iceland What is at stake? Glaciers in the hydrological cycle 0,001% 0,01% 2,15% 0,63% 97,2% Global sea level rise 0.2 – 0.5 m ? Depending on climate scenarios IPCC 2007 Contributions to rising sea level 1993-2003 1961-2003 3.1 +/- 0.7 mm year-1 Varmaútþensla Antarctica Greenland ? Jöklar utan heimskauta Sea level equivalent: 61.1 m SLE: 7.2 m ? Glaciers outside polar regions SLE 0.5 m Thermal expansion IPCC AR4 Glaciers in polar regions Sea level equivalent: SLE 69 m Arctic islands of N-Europe Canadian Arctic islands (Spitsbergen, Novaya Zemlya) Greenland SLE: 7.2 m Antarctica SLE: 61.1 m Arctic glaciological research require international collaboration Melting of the ice cover on the Arctic Ocean The most visible expression of global warming 1979 2005 Of global importance for ship-transport of goods and cargo Muli-national collaboration of Arctic research Impact of climate change in the Arctic • • Substantial decrease in Arctic Sea Ice, thinning and reduced area Amplified by reduced albedo • Thawing of permafrost, release of methane • Extinction of many organisms that are adapted to this habitat, endemic species. – What are the walrus going to eat if they have to come ashore in the summer? • Models predict: – 5 cm sea-level rise from melting in Greenland during the 21st century. Greenland may almost completely melt during the next 1,000 years (starting melting rapidly by 2100). Mid-latitude glaciers Sea level equivalent: SLE 0.5 m Iceland Norway Alps Pyrenees Alaska The Third Pole Pacific Coastal Range Rocky Mountains Patagonia New Zealand Third-pole glaciological research require international collaboration Glacier changes in The Tibetan Plateau and the Himalaya region have economical and social impact on more than 1000 million people Indus Ganges Brahhmaputra Salween Yellow river Yangtze Mekong Tropical glaciers Kilimanjaro Mount Kenya New Guinea, Indonesia Ecuator Bolivia Northern Andes Impacts of glacier retreat on: Hydrology Seasonal runoff changes. Excessive Flooding. Water arrives earlier than needed Glacial lakes outburst floods (e. g. Nepal, Bhutan) Sediment transport Replenishment of reservoirs for drinking supplies, domestic use, Irrigation, droughts (e. g. Mongolia, western China, Pakistan, Afghanistan, India, Tajikistan, South America). Societal matters, regional planning, geoengineering Development, adaptation Engineering and transportation, design of roads, bridges, hydropower plants, Tourism, ski resorts, mountain recreation. Food production, Reduced Agricultural Output Public health Political conflicts Ecosystems Animal, Bird, and Fish Habitat Loss. – Plants. Oceans Sea level rise, effect on coastal regions worldwide. Alterations to the ocean currents, thermohaline circulation. Longer term albedo changes, climate feedback. The Ocean’s Conveyor Belt Warm Cold Iceland is located at the border of warm and cold ocean and atmospheric currents Heavy precipitation Mild tempeartures Global sea level rise 0,8 – 1 m ? New predictions Potential dynamic instability of landbased glaciers is not considered in the present IPCC report May contribute < 2 m before 2100.
