Gruppe 5: Klimamodellering og analyse. Nils Gunnar Kvamstø David B. Stephenson

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1 Gruppe 5: Klimamodellering og analyse Nils Gunnar Kvamstø David B. Stephenson

2 Personer: Nils Gunnar Kvamstø, 1. amanuensis Tore Furevik, Professor 3 N.N. 1. amanuensis/prof Helge Drange (Nansensenteret), professor II David Stephenson (Exeter, UK), professor II 3 Gudrun Magnusdottir (UC, Irvine), professor II Frode Flatøy, Bjerknesforsker Jürgen Bader, Bjerknesforsker Ina Kindem, Bjerknesforsker 5 18 Asgeir Sorteberg, Bjerknesforsker Anne Sandvik, Bjerknesforsker Ivar Seierstad, PhD Dag Johan Steinskog, PhD Tarjei Breiteig, PhD Gunn-Elisabeth Olsen, PhD 7 Ingo Bethke, PhD Kristin Richter, PhD Ole Segtnan, PhD Sentrale samarbeidspartnere: BCCR NERSC, BCCR, met.no, NILU, Matematisk inst./statistikk, Para//ab, IFT

3 Visjon Øke fysisk forståelse av klimavariabilitet på nordlige halvkule med spesiell vekt på rollen til havet Pågående aktiviteter * Studier på hvordan tilstanden i atmosfæren endres ved økt drivhusgassinnhold. * Studier på hvordan endringer I underlaget (havoverflate og sjøis) påvirker atmosfæretilstanden. * Klimaprediksjon simulering av klimautviklingen de neste år

4 Simulert utvikling av klima nord for 60N K ºC ENSEMBLE MEAN ENSEMBLE MEAN RANGE + 1 STD SRES A1B (CO 2 ENDS AT 700 ppm) SCENARIO: SRESA1B YEAR ºC Sprik i estimat Naturlig variabilitet Modellfeil Fysisk forståelse nødvendig for å vurdere usikkerhet

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6 Våre områder er viktige! Vekselvirkninger mlm luft hav og is påvirker klimavariasjoner over nordlige halvkule. Verktøy: Analyse av målebaserte data Globale modelle (numerisk lab C (Drange et al., Furevik and Nilsen, AGU monograph, 2005

7 Eksempel: Seierstad og Bader (2007)

8 Oppvarming som strekker seg ut over Arktis

9 Omlegging i sirkulasjon

10 A Changing Climate for Prediction Professor David B. Stephenson Chair in Statistical Analysis of Weather and Climate, U. of Exeter Adjunct Professor, Geophysics Institute, University of Bergen Joint work with Professor Peter Cox, University of Exeter Exeter Climate Systems (

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12 The changing nature of climate science Intergovernmental Panel on Climate Change (IPCC) has largely been addressing the questions: Is climate changing significantly Are human s to blame? The latest IPCC report answers a clear YES to both these questions, and many are therefore convinced of the need to act. Scientists are now being asked much harder question: what should we do?

13 IPCC 4th Assessment Report Uncertainties in 21st Century Global warming

14 IPCC 4th Assessment Report Probabilities and Patterns of Global Warming

15 Relative uncertainty in predicted decadal mean temperature versus prediction lead-time Initial Condition Uncertainty Total Uncertainty Emissions Scenario Uncertainty Process/Parameter Uncertainty

16 Current Approach to Climate Prediction Socioeconomics Carbon Cycle & Atm. Chemistry Climate Model GHG Emissions GHG Concentrations Climate Change Climate Prediction to Inform Mitigation Policy Socioeconomics Carbon Cycle & Atm. Chemistry Permitted GHG Emissions GHG Concentrations Policy Impact Assessment Climate Model Climate Change GHG conc. scenarios to avoid dangerous Climate Change Bodies on the street Vulnerability Assessment

17 Conclusions The questions being asked of climate change scientists are changing fast and we need to respond to the changing agenda. To inform adaptation policy we need to develop higher resolution climate forecasts on decadal (rather than century) timescales, constrained more effectively by modern observational data. To inform mitigation policy (under the UNFCCC) requires a reversal of the process typically used for climate projections; starting at climate impacts/vulnerability and ending with diagnosed permissible emissions. Both adaptation and mitigation require better use of data to constrain predictions.