Arctic Climate Change

1. Arctic Climate Change John C. Fyfe Canadian Centre for ClimateModelling and Analysis

2. Three Main Points • The Arctic interacts strongly with the global climate system • The Arctic is changing rapidly, and faster than models have predicted • The Arctic must be seriously considered in any mitigation strategy

4. The Arctic has warmed at twice the global rate over the past 100 years [AR4 WGI SPM]

5. The Arctic has warmed at twice the global rate over the past 100 years [AR4 WGI SPM]

6. Observed and Simulated Temperature Temperature anomaly (K) Year Human activities have caused significant warming in the Arctic [Gillett et al., Nature Geoscience, 2008]

7. Snow-Ice Albedo Feedback Ann. Review of Marine Science, 2009 More solar energy is being deposited in the Arctic Ocean [Perovich et al., GRL, 2007]

8. Summer Autumn Heat Heat Heat transport is also contributing to Arcticamplification [Graversen et al., Nature, 2008]

9. 2006 2008 2007 Arctic sea ice extent in summer has decreased by 7.4% per decade since 1978 [AR4 WGI SPM] Observed Minimum Ice Extent

10. September Ice Extent 1980 2005 2007 Source: Annual Review of Marine Science, 2009

11. Observations IPCC AR4 Models None of the models show trends comparable to observations [Stroeve et al., GRL, 2007] Observed and Simulated Minimum Ice Extent 10 8 6 4 2 0 Minimum sea ice extent,106 km2 1960 1980 2000 2020 2040 2060 2080 2100 Year

12. Some Impacts of Sea Ice Loss • Increased coastal erosion with longer fetch • Increased primary productivity • Diminished polar bear health and abundance • Northern passage, shelf exploration and exclusive economic zones

13. SLR from 1993 to 2003 (mm/yr) From AR4 WG1 Table SPM.1

14. Loss from Greenland has nearly doubled sincelast reported [Allison et al., pers. comm., 2009]

15. Discharge from many major outlet glaciers has accelerated markedly [Alley et al., Science, 2005] Jakobshavn GlacierWest Greenland 2001 2006 1851 Source: Konrad Steffen Source: NASA Space Observatory

16. 1991 2006 Acceleration triggered by the arrivalof warm ocean waters From Holland et al., Nature Geoscience, 2008

17. Typical Climate Model Resolution Model shortcomings limit our ability to make accurate projections of global sea level rise From AR4 WG1 Fig. 1.4

18. Sea Level Rise by Year 2100? Gregory et al., Nature, 2004Runaway melt of the GIS at ∆T > 3°C IPCC, 2007GlobalSLR <0.6 m + 0.2 m = 0.8 m Pfeffer et al., Science, 2008GlobalSLR = 0.8 to 2.0 m Carlson et al., Nature Geoscience, 2008SLR from GIS could be > 1.3 m

19. Models predict a “super recovery” of the ozone holedue to GHG emissions [Erying et al., JGR, 2007]

20. What Came Out of CoP-13 in Bali? • Bali Declaration: “Emissions must peak or decline in the next 10 to 15 years, so there is no time to lose” • Bali Roadmap: Negotiate and meet again in CoP-14 in Poznań and reach an agreement in Copenhagen in 2009

21. Globe And Meanwhile the Warming Continues From AR4 WG1 Fig. 11.18

22. Arctic Climate Change John C. Fyfe Canadian Centre for ClimateModelling and Analysis