A. SATHY NAIDU Institute of Marine Science University of Alaska Fairbanks CLIMATE CHANGE EFFECTS ON THE ALASKAN COASTAL ENVIRONMENT AND COMPARABLE ASPECTS IN INDIA A SPECIAL PRESENTATION AT THE 3 RD ROUND TABLE ON CLIMATE CHANGE, AGRICULTURE & SUSTAINABLE DEVELOPMENT, CHENNAI – INDIA

GREENHOUSE EARTH Courtesy: National Geographic

THE CIRCUM-ARCTIC SETTING

INTRODUCTION Coastal and near shore regions of the North Alaskan Arctic exhibit unique geomorphic features shaped by ice and very sensitive to climate change – world’s coastline is about one million kilometers long – Alaska has 50,000 km of coast One of the serious and certain consequences of a presumed global warming scenario is an increase in sea level – the world’s population is concentrated along the coasts Rise in sea level over past 100 years has had severe impacts – present rate is ~2 mm/yr – this rate is 10-fold higher than the average of the past several thousand years

IMPACTS OF ARCTIC CLIMATE CHANGE Warming up to 1 o C per decade noted over last three decades. Possibly related to circumpolar vortex pattern of atmospheric circulation such as Arctic Oscillation (AO). Models indicate warming by year 21OO – may vary from 3 to 10 o C. Adapted from: Impacts of Arctic Climate Change. G. Weller and P. Anderson, CIFAR, University of Alaska Fairbanks

IMPACTS OF ARCTIC CLIMATE CHANGE  Fisherieslosses and displacement of fish stock  Forestryincreased insects, fire  Coastalloss of property  Reindeerecosystem changes, reduced access to food  Subsistencedisplacement and reduced access to marine mammals  Infrastructurethawing roads, houses, airfields and pipelines  Transportationairfield and railroad problems  Tourismmelting of scenic tidewater glaciers and disappearance of drifting sea ice Potential positive impacts Adapted from: Impacts of Arctic Climate Change. G. Weller and P. Anderson, CIFAR, University of Alaska Fairbanks Forestryincreased productivity  Agriculturelengthened growing season  Transportationloss of sea ice for ship passage  Tourismlandscape changes: easier access Potential negative impacts

OFFSHORE ICE COVER

RECESSION OF ICE COVER

LOSS OF POLAR BEAR HABITAT

COASTAL EROSION The North and Northwest Alaskan Arctic are characterized by one of the highest rates of coastal erosion in the world. This high rate has great adverse impact on the coastal sediments and industrial installations as well as leading to changes in state/federal boundaries offshore. Primary cause of high coastal regression is thermo-erosion of permafrosted (60–90% ice) coastal bluffs augmented by: storms plus wave action sea ice ride up

COASTAL EROSION Source: Naidu et al., 1984 Photo credit: Jim Bockheim

RELEIF OF ARCTIC ALASKA

VEGETATION MAP OF ARCTIC ALASKA

Oriented Thaw Lakes COASTAL LAKES OF ARCTIC ALASKA

ARCTIC FOOD CHAIN AND ECOSYSTEM: A CONCEPTUAL MODEL After: R. Gradinger

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