Let s begin with a focus on current scientific understandings of climate change at global scales and across hundreds of thousands of years.

Transcription

1 Good Morning

2 Let s begin with a focus on current scientific understandings of climate change at global scales and across hundreds of thousands of years.

3 Projected by IPPC B2 Reference Case to go to CO 2 Concentrations and Proxy ppmv by the Year 2100 Temperatures from the 400,000 + years Vostok Ice Core Data Set. CO 2 levels now 25% above the previous maximum of ~300 ppmv about 325,00 years ago

4 Temperature Reconstruction for the Past 2000 Years Last 100 Years Last 100 Years Alaska and western Canada, the average winter temperatures have increased by as much as 3 to 4 C over the past 60 years, which is a significant increase given that the global average increase over the past 100 years has been only about 0.6±0.2 C.

5 Global-mean temperature over the past 125 Years, with 2005 being the highest on record. About 0.8 o C over 125 years Source: NASA/Hansen, et al 2006

6 What are some of the recent scientific findings regarding climate change and how important are they in understanding the consequences for societies globally and within the Arctic region?

7 What role do the Ocean s Play in Climate Change? Oceans contain 97% of Earth s water, hence they are fundamental in the global hydrological cycle. Oceans experience 86% of evaporation, hence they are central to the energy exchange on planetary scales. Oceans receive 78% of planetary precipitation; for example, a 1% increase in Atlantic precipitation equals the annual Mississippi runoff. The oceans control the timing and magnitude of the changes in global climate system.

8 Why are the oceans Important? Because, that is where the heat goes! Data from Levitus et al, Science, 2001

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10 Global Warming of the World s Oceans (T.P. Barnett, et al 2005) No Anthropogenic Forcing (Blue) With Anthropogenic Forcing (Green) Observational Data (Red)

11 Earth s Energy Imbalance: Confirmation and Implications James Hansen, et al (Science 2005) Significance of Hansen s Science Paper: The Earth is now absorbing / W/m 2 more energy from the Sun than it is re-emitting back into space. This imbalance is confirmed by precise measurements of increasing ocean heat content over the past 10 years. Major implications: An expectation of additional global warming of about 0.6 o C without further change of atmospheric composition.

12 Does this Melting of Sea Ice have other Effects, such as an Impacts on Oceanic Circulation? Critical Region Critical Region

13 Changes in Oceanic Temperatures of Importance.

14 Conveyor OFF Strong cooling in North Atlantic Warming everywhere else No net global change

15 QuickTime and a YUV420 codec decompressor are needed to see this picture. Sea Ice Changes from 1979 to 2003

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17 Status of the Arctic Sea Ice. What happened in 2005? Lowest on record during human times

18 Changes in the absorption of heat by the ocean as the ice disappears: switches from 85% reflected back to 85% absorbed. QuickTime and a YUV420 codec decompressor are needed to see this picture.

19 GFDL Simulation Projects 50% Reduction by 2050 Five Models Project Sea Ice Extent for Mid-September Five Models Project Sea Ice Extent for Mid-September

20 Northern Sea Route is 45% Shorter than through the Suez Canal The ACIA models projects that the current navigation season of days per year will increase to 3-6 months/yr by 2080, with one model indicating an ice-free summer by 2040

21 World s Petroleum Potential Verdens uoppdagede petroleumspotensiale Canada N. Afrika Kaspihavet Rest of Midt-Østen World North Africa, Middle Resten East av verden Arktis Arctic Greenland 7 Alaska Barents Sea 2. Southern Kara Sea and Western Siberia 1: Barentshavet 2: Sørlige Karahavet og Vest-Sibir 3: Nordlige Karahavet 4: Laptevhavet 5: Øst-Sibirhavet 6: Chuchihavet 7: Alaska North Slope 8: Øst-Grønnland 3. Northern Kara Sea 4. Laptev Sea 5. East Siberian Sea 6. Chukchi Sea 7. Alaska North Slope 8. East Greenland Norway Russia 5

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23 The Greenland Ice Sheet Dominates Land Ice in the Arctic Over the past two decades, the melt area on the Greenland ice sheet has increased on average by about 0.7%/year (or about 20% from 1979 to 2005). Source: Business Week Aug. 2004

24 Greenland Ice Sheet Melt Rates 2005

25 Note: The substantial warming across the Arctic, (upwards of 10 o C or more), from very warm in the ice covered ocean to less warm in Greenland and Scandinavia.

26 Greenland s Annual Temperatures are Projected to Increase Projected to be in the range of to 6 0 C Climate models indicate that the local warming over Greenland is likely to be up to three times the global average.

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28 Tuvalu Many Island Nations are lowlying coral atolls (Kiribatio, the Marshall Islandso, Tokelauo and Tuvalu), many of which have only a few meters of topographic height (~ couple of meters) and hence 1 or 2 meters of sea level rise results in a loss of ~ 50% or more of their island s land area.

29 Two Issues of Global Importance: The increases in the acidity of the oceans, and Methane, a very powerful greenhouse gas.

30 Creates Carbonic Acid in the Ocean

31 World Bank recently projected 750 ppm for CO 2 levels by 2100

32 Methane has increased from ~ 700 ppbv to over 1600 ppbv or over a doubling of the concentration of methane during the past 150 years or so. CH 4 now about 1750 ppbv CO 2 now about 385 ppmv Greenhouse Gas record from the Vostok Ice Core

33 Sources of Atmospheric Methane (IPCC 2001): Human Sources (70%): Energy (20% of Human Sources) Landfills (10% of Human Sources) Ruminants (20% of Human Sources) Rice Production (30% of Human Sources) Biomass Burning (15% of Human Sources) Other (5% of Human Sources, e.g., abandon coal mines, iron and steel production, etc.) Natural Sources (30% of Natural Sources): Wetlands (75% of Natural Sources) Termites (15% of Natural Sources) Oceans (7% of Natural Sources) Hydrates (3% of Natural Sources) To Watch

34 Projected by IPPC B2 Reference Case to go to 621 ppmv by the Year 2100 CO 2 Levels Now 621 IPCC B2 Reference Case Projections for CO 2 Concentrations for 2100, depicted on the 400,000 year Vostok ice core data set.

35 There is a fundamental asymmetry between the time scales that the climate system reacts to increases in greenhouse gases and the time scales to recover from such increases. Even if we Stop CO 2 Emissions Now, Stabilization will Require Several 100 Years

36 There is a fundamental asymmetry between the time scales that the climate system reacts to increases in greenhouse gases and the time scales to recover from such increases. Reduction CO 2 missions sooner, moves these delayed consequences downward and reduces the time required to stabilize the responses.

37 Major Geopolitical Issues are Unresolved across the Arctic Basin ACCESS: Issues of Access and Rights of Passage through the Northern Sea Route (Russia) and the Northwest Passage (Canada) SEAWARD CLAIMS: Claims of seaward ownership within the Arctic oceanic basin. Median Line Method (i.e., Divide into areas proportional to the amount of coastline of a country), and the Sector Method (Divide into areas by essentially longitudinal line from the countries to the pole). BOUNDARY DISPUTES: Many boundary disputes still exist. VENUE: Is the Law of the Sea the venue to resolve these geopolitical issues, or other international frameworks required?

38 Thank You