Glaciers and climate change in Iceland:Mass balance and climate scenarios

Applications in the Himalaya

Helgi BjörnssonInstitute of Earth Sciences, Universtiy of Iceland

Dagfinnur Sveinbjörnsson

Öræfajökull

Mýrar

VatnajökullLangjökull Hofsjökull

MýrdalsjökullEyjafjallajökull

Glaciers cover 11% of IcelandThey are rapidly shrinking

Drangajökull

Snæfellsjökull

20 years of precipitation on Iceland

Firnline

Ablation area

Accumulation area

Ice flo

w

Runoff

Acquisition of basic data:Glacier geometry: surface and bedrock Glacier mass balance Ice dynamics Glacio-meteorology Drainage of meltwater

Modeling:Mass balanceIce dynamicsGlacier response to climate

Analysis of glacial evolution

1995-2007: 10 m 80 km3

accelerating volume loss

Mass balance

Approach:Field observations & modelling ⇒ prediction given climate scenarios

Glacier responseGlac

ier fl

ow m

odel

Climate scenario

Mass balance model

0.18 °C/decade

0.25 °C/decade

3.4 mm/decade.

Climate change scenario for Icelandic highland

Note:Volumes and areas are normalized to present day valuesSpecific runoff is from the present day glacier covered area

Predicted response to CE climate change scenario

Model responses shown for three Icelandic glaciers:Vatnajökull, Langjökull and Hofsjökull

Year: 1990

Year: 2000

Year: 2010

Year: 2020

Year: 2030

Year: 2040

Year: 2050

Year: 2060

Year: 2070

Year: 2080

Year: 2090

Year: 2100

Year: 2110

Year: 2120

Year: 2130

Year: 2140

Year: 2150

Year: 2160

Year: 2170

Year: 2180

Year: 2190

Consequences

• Glaciers disappear in 100-200 yrs

• Discharge from glaciers increases over next 50 yrs and then decreases

• Seasonal rythm in discharge changes, some rivers disappear

• River discharge = precipitation

• Changes in sediment load of rivers

SourcesSources ofof jjöökulhlaupskulhlaups

Research Program on Glacial Changes in the Himalaya and the Consequences for Economic and

Social Development

Proposal initiated by the President of IcelandHE Ólafur Ragnar Grímsson

Indus, Ganges, Brahmaputra

Research steps toward prediction

1. Collecting required basic field data

2. Develop glaciers models – mass balance– physical flow dynamics

3. Combine mass balance and flow models and run for different climate scenarios

4. Prediction, analyses of consequences and adaptation

• Requires education and training of young scientists ,-informed and constructive political reactions

Consequences of Himalayan glaciers disappearing in 40-70 years

• Hydrology– Flood hazards, outburst floods

– Seasonal changes in river discharge, drinking water, irrigation

– Drought

– Changing design criteria of bridges and hydropower plants

• Regional planning and development, adaptation, mitigation– Agriculture, food production

– Transport

– Tourism

• Impact on ecological systems, human health