How well can we predict the unpredictable climate?Environment and security seminar, Oslo, 8 Dec. 2004

Prof. Olav Orheim, Director, Norwegian Polar Institute

How well can we predict the unpredictable climate?Environment and security seminar, Oslo, 8 Dec. 2004

Prof. Olav Orheim, Director, Norwegian Polar Institute

Content of this presentation

The overall climate picture–Uncertainty - the ”loaded dice” and

can we insure against the risk?– Lack of knowledge and IPY 2007-2008

We are the first generation that influences global climate and the last generation to escape the

consequences

Norwegian Glacier Museum, 1991

Natural climate changes _ CO2 level in 2004

CO2 leads CH4 which leads temp.

Source: EPICA team. Nature, 10 June 2004

JTH 17-07-2001 9 COP6bis /SBSTA

SPM 1b

Variations of the Earth’s surface temperature for the past 1,000 years

Source: Meteorologisk Institute, Oslo, November 2004

Predicting the unpredictable climate

The greenhouse effect is certain - without it no humans!

Uncertainties for the future include:

• Balance between natural and human effects, including variations in output of the sun.

• Feedbacks, including clouds, albedo, snow and ice, vegetation, carbon storage, atmosphere/ocean interaction

Averages can be predicted – not single events.

This is the ”loaded dice”

JTH 17-07-2001 14 COP6bis /SBSTA

Variations of the Earth’s surface temperature; 1000 to 2100

Comparing observed and projected changes

Comparing observed and projected changes

1954-2003 Winter (D,J,F)

1954-2003 Winter (D,J,F)

1990’s -2090’s Winter (D,J,F)

1990’s -2090’s Winter (D,J,F)

Southern Europe July/August temperatures, as deviation from 1961-1990 mean.

* below is 2003 summer

Observed (black) and climate models (colour) Source: Stott, Stone, Allen. Nature, 2. Dec. 2004

Daily mortality, B-W, GermanyPer 100 000 people. Note 2003 heatwave

Source: Schär and Jendritzky, Nature 2 December 2004.B-W = Baden-Wurttemberg, Sozialministerium

The Greenland Ice SheetThe Greenland Ice Sheet

Satellite Data Documents the Changes

Satellite Data Documents the Changes

Insuring against climate change?

Association of British Insurers in October 2004:• ”Global economic losses caused by natural weather catastrophies have increased 10-fold over past 40 years.”

• ”Damage now increasing 2-4%/year from changing climate.”

Mainly floods, storms,avalanches

Sea level now rising 2 mm/year, Holland sinks 2 cm/year

The Pentagon weather nightmare (“Abrupt climate change”)

“The day after tomorrow”

Understanding and Projecting the Changes in the Oceanic Conveyor Belt is a Critical Question for Science

Understanding and Projecting the Changes in the Oceanic Conveyor Belt is a Critical Question for Science

Note Downward

Trend beginning in late 1970’s

Nine (9) Models

Source: Cubasch et al. 2001

Geophysical InstituteUniversity of Bergen

Nansen Environmental andRemote Sensing Center

Hansen, Turrell and Osterhus (2001), updated by Hansen et al. (2004)

Observed overflow through the Faroe-Bank Channel

No trend – but the time series is short

Observations so far show no weakening of the ocean transport

International Polar Year 2007-2008

• An intense burst of activity combining, ground observations and satellites, to give a data set for improving climate models and predictions

• A permanent legacy of improved Arctic cooperation

• Arctic/Antarctic ocean teleconnections – thermohaline circulation and the climate of lower latitudes