Post on 28-May-2020
transcript
Climate Change and the Cryosphere:
Snow, Water, Ice and Permafrost in the Arctic
Margareta Johansson
Dept. of Earth and Ecosystem Sciences, Lund UniversityRoyal Swedish Academy of Sciences
AMAP, IASC, IASSA, IPY, WCRP/CliC
Large part of the presentation has been prepared by AMAP Secretariat
What is the cryosphere?
The world of frozen water:• Ice sheets and glaciers• Snow• River and lake ice• Permafrost
ObjectiveSynthesize knowledge of changes in Arctic snow, water, ice and permafrost conditions and their effects
SWIPA background
•Project focuses on changes in the Arctic cryosphere•Benchmark is the 2005 ACIA report•Assessment based on peer-reviewed science including IPY-results•Approximately 200 scientists have contibuted Guided by an integration team (The SWIPA IT)•To be delivered at the Arctic Council Ministerial in Nuuk, May 12, 2011
Science Report
The Greenland Ice Sheet in a Warming Climate
Warming temperatures during past few decades has caused
• Increased melting of surface of the ice sheet
• Increased flow of ice from the margins and discharge of icebergs from glaciers
• This dramatic loss has surprised scientists
Greenland Ice Sheet
Impacts of changes in the Greenland Ice Sheet
Sea level rise
Ice caps and mountain glaciers
Changes in glaciers and ice caps
• Widespread reductions in glacier-covered areas in Arctic
• Rates of retreat have increased over past 15 to 20 years
• Russian mountain glaciers have lost from 17% to 50% of surface area in past 50 to 60 years
• Icebergs calved from Arctic glaciers can be serious hazard to navigation
Sea ice in the Arctic
Effects of loss of sea ice• Creates a positive feedback to warming:
open water absorbs far more sunlight and heat than ice and snow
• Results in loss of essential habitat for animals such as polar bears and walrus
New sea routes
Map prepared by Grid-Arendal
Lake and river ice
• Freshwater ice on lakes and rivers is dominant feature of Arctic
• Lakes covered by ice for 6 to 12 months a year
• Climate change resulting in earlier dates of ice break-up
• Some lakes in northern High Arctic are becoming ice-free in summer for first time
Impacts of changes in lake and river ice
Photo downloaded from http://icetruckers.blogspot.com
Permafrost?!Permafrost?!
= any material that stays at or below 0 °C fortwo or more consecutive years
Active layer
Permafrost
Unfrozen material
Permafrost distribution in the ArcticPermafrost distribution in the Arctic
Map prepared by AMAP based on Brown et al., 1998
Permafrost distribution in the ArcticPermafrost distribution in the Arctic
Map prepared by AMAP based on map drafted by Hugues Lantuit
Romanovsky et al., 2010
Ground temperaturesGround temperatures
Warming typically between 0.5 to 2 °C
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Active Layer Thickness (ALT)Active Layer Thickness (ALT)
CALM data archieve
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Projections for year 2090Projections for year 2090
Extensive thawing in the southern boundary of permafrost region
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Changes in hydrologyChanges in hydrology
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Drying of ponds
Callaghan et al., in press
1970
2009
Watterlogging
Changes in hydrologyChanges in hydrology
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Christensen et al., 2004
Carbon storageCarbon storage
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Tarnocai et al., 2009
Twice as much carbon stored in the ground than is in the atmosphere today
Dissolved CHDissolved CH44 in the East Siberian in the East Siberian Arctic Shelf in summerArctic Shelf in summer
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Shakhova et al., 2010
Arctic shelves can contain 1300 Gt of C
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Million dollar question!Million dollar question!
Will the Arctic be a sink or a source of carbon in the future?
Mcguire et al., 2009
Нарьян-Мар
Мурманск
Салехард
Ханты-Мансийск
Горно-АлтайскИркутск
Якутск
НорильскВоркута
Игарка
Тикси
Анадырь
Березово
Братск
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Infrastructure susceptibility to permafrost Infrastructure susceptibility to permafrost thaw in Russiathaw in Russia
High
Susceptibility of buildings and engineered structures to ongoing climatic and permafrost changes
Moderate Low
Updated from Instanes and Anisimov, 2008
Snow is a dominant feature of the ArcticSnow is a dominant feature of the ArcticAffects all the other cryospheric componentsAffects all the other cryospheric components
SWIPA
Glaciers and Ice caps
Sea Ice and River and Lake Ice
Permafrost
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Snow cover durationSnow cover duration
3.4 days per decade 1972-2009
Derksen et al., 2009
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Projected changes in snow water equivalent Projected changes in snow water equivalent between 1970between 1970--1999 and 20491999 and 2049--2060 2060
Brown and Mote, 2009
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Projected changes in snow cover duration Projected changes in snow cover duration between 1970between 1970--1999 and 20491999 and 2049--2060 2060
Brown and Mote, 2009
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Snow cover Snow cover –– an important component of climate, an important component of climate, hydrological and ecological systemshydrological and ecological systems
Brown and Callaghan
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?85-95% reflected by
snow
10% reflected by ocean water
20% reflected by tundra vegetation
5% reflected by black spruce
forest
Albedo and insulationAlbedo and insulation
Current trendsCurrent trends
Future predictionsFuture predictions
Why do we care?Why do we care?
Hydropower industryHydropower industry
74.535.139.466.331.534.862.328.134.2 Production (TWh)
81.651.230.471.349.921.566.053.512.5 Runoff (TWh)
ASWASWASW
ECHAM-B22071-2100
HadAM-B22071-2100
Reference period1960-1991
Gode et al., 2007
ConclusionsConclusions
• The Arctic cryosphere has changed dramatically during the last decade
• Natural variability is high and the system is complex but the rate of change has taken scientists by surprise
• Impacts of changes in the cryosphere change living conditions in the Arctic and have significant global implications
• Changes in the cryosphere provides challenges as well as opportunities
Thank you!