Climate change scenarios and impacts assessments for North Atlantic from ICES and other European groups Ken Drinkwater Institute of Marine Research and Bjerknes Center for Climate Research, Bergen, Norway NW Atlantic Ocean Climate Change Workshop Bedford Institute, Dartmouth, Canada February 16, 2010

ICES Produced some reviews on CC, most recently for OSPAR Presently writing a more complete review of climate change and its biological impacts ICES wrestling with what its role should be. CC is in the ICES scientific plan. However, most of the work on climate change and its impacts financed by EU and national funding agencies. They are determining more what the priorities are. Few physical oceanographers in ICES, and fewer working on global or even regional models for future forecasting. Few ICES scientists involved in IPCC process.

EU (Frameworks) Concerned about CC Have been funding work on climate variability and change over last 10+ years. Funding is increasing. Concerned about climate scenarios and effects on fisheries and underlying ecosystem. Acidification also becoming of interest. (Humboldt Institute advertised 10 post-doc positions) Call in 2008 on Tipping points in the Arctic EU Framework 7, more concern expressed about economic opportunities, adaptation, governance issues especially for the Arctic (e.g. call for proposals on economic effects for the Arctic under climate change; interested in transport, resources and fisheries; 11 million euros over 3-4 years; will be 1 successful proposal)

Nordic Council Concerned about CC Funding 5 new Centers of Excellence on climate change; each for 5 years; covers both marine and terristrial environments (guess maybe 1, perhaps 2 in marine environment) Funds for post-docs, Ph.Ds, networking

Research Council of Norway Very concerned about CC, especially on fisheries Funding Centers of Excellence on climate change; Bjerknes Centre for Climate Change in Bergen funded for 10 years (runs out in 2012) but recently has been given funds from Norwegian government for unlimited time frame of equivalent funds to CoE. Bjerknes Center dealing mostly with physical and chemical aspects of climate change, climate models, regional modelling, some impacts in fisheries, also on energy, coastal regions. Many relevent calls for proposals on climate change and its impacts. Funds for post-docs, Ph.Ds, scientist’s time. Need collaboration with many institutions.

Predicting Future Ecological Changes

1 to 2°C Temperature Increase

Year 1 Year 30 Year 20 Year 10 Likely Polar cod retreats from subarctic into the Arctic Chung et al., 2008, UBC Report

Problems with Bioclimate Envelope Models Assumption that everything else stays the same Only deal with one species at a time – no consideration of prey, predators, competitors Does not deal with connectivity of life history stages.

Future zooplankton production -Barents Sea Production increases in Atlantic Waters Ellingsen et al. (2008) Production decreases in Arctic Waters

Capelin Spawning in Response to Climate Change Huse and Ellingsen, 2008 Present Spawning Future Spawning Direction of distributional shift of adult feeding migration

North Atlantic and Arctic Regional Model Based on ROMS Downscaled from GISS model (used in IPCC (2007) and recommended by Overland and Wang (2007) because of reasonable representation of sea ice) Took atmospheric forcing from last 20 years of 20th Century control run from GISS AOM with 3 x 4 deg lat-long grid. Model Domain Melsom et al., 2009

Observed Modelled T S

North Sea Regional Model Based on ROMS Downscaled from Bergen Climate Model (used in IPCC (2007) Took atmospheric forcing from last 20 years of 20th Century control run from GISS AOM with 3 x 4 deg lat-long grid. Mean winds from BCM (blue) and (red).

Lessons learned from downscaling Need to choose GCM to downscale from carefully – one that does a reasonable job in hindcasting recent conditions. Need to downscale from more than one GCM, preferably several and create ensemble mean from the results. Need to couple atmospheric and oceanic models. Regional results will reflect GCM results (Jacob et al., 2007). Therefore, need to improve GCMs. For projections over the next 30+ years need to start with present conditions.

Dr. Kevin Trenberth (head of Climate Analysis Section, NCAR) states: (...) None of the models used by IPCC are initialized to the observed state and none of the climate states in the models correspond even remotely to the current observed climate. In particular, the starting state of the oceans, sea ice, and soil moisture has no relationship to the observed state at any recent time in any of the IPCC models.(...) IPCC GCMs: Limitations  N o initialisation to the present state (particular problematic for the ocean) (…) I postulate that regional climate change is impossible to deal with properly unless the (global climate) models are initialized (to the current state).

Some Present IPCC GCMs Limitations  Small to large (1-3  ) scales: mixing and turbulence, friction, waves, clouds, marine optics  Arctic sea ice conditions not well represented  Tides, tidal variability has the potential to impact significantly on climate: e.g. (W.Munk et al., 2001)  No variability considered (temporal, spatial) in tidal forcing (IPCC, 2007)  Generally poor representation of ENSO, NAO, etc.

Some general statements Earlier migrations northward, later retreats southward Species at southern limits of their geographic distribution will decrease while those at northern limit may do well Growth rates expected to increase in general but depends upon what happens to prey Difficult to forecast because of new interactions between species, lack of knowledge of processes

Conclusions 1 Uncertainty due to global, regional and biolgical models is (much?) larger than the signal to study Need to develop uncertainty estimates of future scenarios Improved understanding of processes and better paramaterization of the models Develop models that include fish and fisheries

Conclusions 2 IPCC scenario model predictions (and consequently the RCMs based on these) are only of limited use for regional climate change assessment Presently might be able to learn as much performing controled sensitivity tests with validated regional models Decadal scale predictions from GCMs might provide improved forcing data, but loose performance after approx. 1 decade (??) Inspite of difficulties need to“get on with it“.

Other points 1.We should not worry about failure – it points to our lack of understanding or incorrect paramaterization. We only learn when we are making mistakes. 2. Expect surprises!

...and for BergenThank you! Bergen expects more of this under climate change!

Cod Recruitment and Temperature Mean Annual Bottom Temperature Temp Warm Temperatures decreases Recruitment Warm Temperatures increases Recruitment Recruits Planque and Fredou (1999)

If BT < 5° and T warms stock recruitment generally increase If BT between 5° and 8.5°C little change in recruitment If BT >8.5°C recruitment generally decreases If BT 12°C we do not see any cod stocks GB

Effect on abundance of 1°C increase Increase No change Decrease Collapse ?

2-3°C Temperature Increase

3-4°C Temperature Increase

Possible effect of global warming and shut down of the Atlantic thermohaline circulation Wood et al Low probability – high impact

What do the models suggest? Large uncertainty Most climate models produce 20-30% reduction in the strength of the AMOC The associated reduction in the poleward transport of heat is less than the atmospheric warming

Food web in Atlantic waterFood web in Arctic water Changes in ecosystem function (Barents) The food web changes may be far more dramatic for the higher compared to the lower trophic levels Falk-Petersen et al. 2007

There is the possibility that boreal species from the Arctic and Pacific will move into the Arctic and may start to mix.

What do we need to Improve Predictions of Future Ecological Changes?

What do we need? More emphasis on quantitative estimates (mechanistic modelling) Better understanding of the processes Improved parameterization of the models Regional models Measure of uncertainty

What is the role of observationalists? -Observationalists and Modellers need to work closer together -Modeller’s to help determine what, where and how often observationalists should measure. -Observationalists should provide more feedback on model results (requires available model results, positive criticisms) -All motherhood statements but not generally done (improving but do we need formal procedure?)

Need Comparative Model Studies 1. Ecosystems are complex – helps determine what is a fundamental process and what is unique. 2. Provides insights that one cannot obtain by looking at a single ecosystem 3. Single model applied to several ecosystems, different models applied to single ecosystem 4. Sharing modelling approaches

Need to include Fishing Effects Models need to be used to determine interaction between climate and fishing and explore effects of management strategies on stocks under climate change scenarios.

Fishing and Climate Multivariate autoregressive models of Baltic cod under increasing salinities. Martin Lindegren, Ph.D. Student, DTU Aqua, Copenhagen

ST error [ o C] Mod-Obs Chapter 8, IPCC, 2007 Surface Temperature error IPCC model ensemble Solomon et al., 2007

Validation of global climate models IPCC, 2007 Drift problems? Sea-ice problems? Solomon et al., 2007

Regional Climate Models One main conclusion:  RegCM are critically affected by the driving large-scale fields from GCM and are very similar to GCM results

Regional downscaling Only very few coupled ocean-amtosphere models on the regional scale Fewer models do ensemble runs using different global models Regional models that are available mostly use previous IPCC global model assessments Few full dynamics ocean model  none reported in the last IPCC Few coupled ecosystem models  none reported in the last IPCC report

Recently: Improved global decadal predictions by improving initialisation Doug Smith et al., 2007, Science Noel Keenlyside et al., 2008, nature Related publications indicated the importance of AMO for the NA region - Knight et al. (2005) and Knight et al. (submitted)

Keenlyside et al., 2008

Next IPCC Runs Going to Earth System Models only Many of the models will be total new with increased number of paramaterizations Will this lead to increased spread in model ensemble?

Higher trophic level dynamics Future scenario GCM low resolution Regional Model high resolution hydrodynamics Lower trophic level dynamics  Need Regional Models  IPCC provides Climate Change scenarios from GCMs: present day from 1960-to present and future up to Multi-Model Dataset (ensemble runs) of climate scenarios (ipcc-data.org)  Use IPCC senario’s for ‘downscaling’ GCMs output by regional models for hydrodynamics (and biota) in regional seas Developing Regional Impacts of Global Change

Huse & Ellingsen, 2008 Fronts will move Modelled currents and Polar Front (thick black line).