Transcript Climat Change Effects on The Alaskan Coastal

CLIMATE CHANGE EFFECTS ON THE ALASKAN COASTAL
ENVIRONMENT AND COMPARABLE ASPECTS IN INDIA
A SPECIAL PRESENTATION AT THE 3RD ROUND TABLE ON CLIMATE
CHANGE , AGRICULTURE & SUSTAINABLE DEVELOPMENT,
CHENNAI – INDIA - 2011
A. SATHY NAIDU
Institute of Marine Science
University of Alaska Fairbanks
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 1oC 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 10oC.
Adapted from: Impacts of Arctic Climate Change. G. Weller and P. Anderson, CIFAR, University of Alaska Fairbanks
IMPACTS OF ARCTIC CLIMATE CHANGE
Potential positive impacts
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Forestry
Agriculture
Transportation
Tourism
increased productivity
lengthened growing season
loss of sea ice for ship passage
landscape changes: easier access
Potential negative impacts
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Fisheries
Forestry
Coastal
Reindeer
Subsistence
Infrastructure
Transportation
Tourism
losses and displacement of fish stock
increased insects, fire
loss of property
ecosystem changes, reduced access to food
displacement and reduced access to marine mammals
thawing roads, houses, airfields and pipelines
airfield and railroad problems
melting of scenic tidewater glaciers
and disappearance of drifting sea ice
Adapted from: Impacts of Arctic Climate Change. G. Weller and P. Anderson, CIFAR, University of Alaska Fairbanks
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
Photo credit: Jim Bockheim
Source: Naidu et al., 1984
RELEIF OF ARCTIC ALASKA
VEGETATION MAP OF ARCTIC ALASKA
Oriented
Lakes ALASKA
COASTAL
LAKES Thaw
OF ARCTIC
ARCTIC FOOD CHAIN AND ECOSYSTEM:
A CONCEPTUAL MODEL
After: R. Gradinger
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