climate change and the cryosphere - smhi/climate change and... · climate change and the...

Post on 28-May-2020

5 Views

Category:

Documents

0 Downloads

Preview:

Click to see full reader

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!

top related