The Arctic on the Fast Trackof ChangeJulienne Stroeve
Climate change in the Arctic: A Bellwether for thePlanetBellwether (1) - One that serves as aleader or as a leading indica...
Amplified Arctic warming         Air Temperature: A1B Scenario by 2100            Global mean warming of ~2.8oC (or ~5F); ...
Signs of warmer Arctic: IncreasingGreenland melt2007 Melting Day Anomalies                                  Melting Index ...
Speed-up of many of Greenland’s outletglaciers                                                  Jacobshavn Glacier retreat...
Glacier Fluctuations: clear indicators of a warmingclimate            McCall Glacier                                1958  ...
Average mass balance of a few Arcticglaciers                  Arctic period 1          y = -6.7749 + 0.0033902x R= 0.23585...
Permafrost degradation                         Permafrost regions                         occupy 24% of the            Sib...
Increases in permafrost temperatureAlaskan permafrost temperatures, 20 m deep temperatures in the active layer            ...
Infrastructure impacts                                                   Chersky, Russia  Alaska                          ...
Methane releasing from lakes                                                        Methane bubbles                       ...
“Greening” of the Arctic                                           Trends in vegetation synthetic                         ...
Poster child of climate change: Arctic sea ice• Frozen surface of the ocean –     Pancake Ice  originates within ocean   ...
Just to be clear, sea ice is noticebergs!            Courtesy Sebastian Copeland
Annual sea ice variability                                                    February             Siberia              Si...
Recent changes in Arctic sea ice•   Previous studies have indicated a decline in annual Arctic sea ice cover since    the ...
Losing the summer sea ice cover                                  Time-series of                                  September...
September 2007: A new recordminimum           Alaska                     Stroeve et al. 2008
What caused the ice cover to drop in2007? • Unusual atmospheric circulation pattern that promoted   warm temperatures and ...
What caused the ice cover to drop in2007? • Big culprit was a thin ice pack.                   Image courtesy of R.       ...
Some recovery since 2007, but still indecline                   1979-2000                   2007                   2008   ...
Large changes in the distribution of iceage• Unfortunately we don’t have long-term records of  Arctic-wide ice thickness m...
Very little old ice left                                                                     Only 320,000 km2 of          ...
Less than 60,000 km2 of 5+ ice left in September2010                                End of Summer Ice Age Distribution    ...
Arctic sea routes opening upNW Passage opening up     (2007-2010)                        NSR also open (2008-2010) Conditi...
Peering into the Future
Continued sea ice loss inevitable• Seasonally ice free Arctic sooner than we expect?               Updated from Stroeve et...
Models suggest ice-free conditions may occurquickly• Climate models suggest once the sea ice cover is  thinned sufficientl...
The set up looks right • Mean thickness (70-90N) in CCSM3 before abrupt   change: 1.71 m • Mean thickness (70-90N) from IC...
Increased Access to the Arctic
Today’s Arctic marine use Hard Minerals Maritime Tourism Major Fisheries                    Zinc & Coal Oil and Gas Summer...
Distribution of known resourcesUSGS estimated in 2008 that 90 billion barrels of oil,1,700 trillion cubic feet of natural ...
Impact on polar bears and other Arctic species
Polar bears under pressure• For every week a bear has  not been hunting, it is 22  pounds lighter.    The bear’s reproduc...
Seals also feeling impacts• Lack of sea ice the  last 2 years in the Gulf  of St. Lawrence led to  loss of thousands of  b...
Community impactsMany Arctic indigenous communities rely on sea ice fortravel and hunting, their main livelihood and basis...
Impacts of changing sea ice on food resources• Reductions in sea ice  are shrinking the marine  habitat for ice-  dependen...
Safety issues• Changes in sea ice -  local and regional  thinning, unusual  cracks, changes in the  timing of break up and...
Community locations threatened• Native communities are facing erosion problems and relocation  of communities (at huge cos...
Climate impacts for the rest of us         Ice albedo feedback: ice edge retreat                 Sea ice in spring
Ice-Albedo Feedback-Amplifier of ClimateChange                                        1.0                                 ...
Arctic Amplification has already emerged     Alaska                                        Autumn (SON) air               ...
Impact of sea ice loss on landtemperaturesPermafrost contains about 1672 Gt of carbon.                       Forcomparison...
Results: Strength of the PCFCumulative NEE (Gt C)                        PCF Start 2023±4                                 ...
Impacts on precipitation/snow cover• A warmer atmosphere changes atmospheric  circulation and is able to hold more water v...
Final Statements• Many components of the Arctic environment are  undergoing large changes.• Land and ocean ice loss in the...
•LearnMoreAboutClimate.Colorado.edu        Climate Change and Colorado’s Future•New website that localizes climate change ...
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The Arctic on the Fast Track of Change

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Julienne Stroeve's lecture at the Longmont Public Library

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The Arctic on the Fast Track of Change

  1. 1. The Arctic on the Fast Trackof ChangeJulienne Stroeve
  2. 2. Climate change in the Arctic: A Bellwether for thePlanetBellwether (1) - One that serves as aleader or as a leading indicator offuture trendsBellwether (2) - Sheep that leads theherd often wearing a bellInuksuk - a stone landmark used asa milestone or directional marker
  3. 3. Amplified Arctic warming Air Temperature: A1B Scenario by 2100 Global mean warming of ~2.8oC (or ~5F); Much of land area warms by ~3.5oC (or ~6.3F) Arctic warms by ~7oC (or ~12.6F) IPCC-AR4 ensemble mean, A1B Scenario, courtesy M. Holland
  4. 4. Signs of warmer Arctic: IncreasingGreenland melt2007 Melting Day Anomalies Melting Index Time Series Courtesy M. Tedesco
  5. 5. Speed-up of many of Greenland’s outletglaciers Jacobshavn Glacier retreat: The rapidly• Current mass loss for retreating Jakobshavn Glacier in Greenland is equally split western Greenland drains the central between surface melt/runoff ice sheet and ice discharge across calving fronts.• Future prediction of Greenland’s contribution to sea level rise is difficult because it is unclear how these outlet glaciers will respond.• Melting of Greenland would produce 7.2 m sea level rise (or about 24 ft). Image courtesy NASA Earth Observatory, Cindy Starr, based on data from Ole Bennike and Anker Weidick (Geological Survey of Denmark and Greenland) and Landsat data.
  6. 6. Glacier Fluctuations: clear indicators of a warmingclimate McCall Glacier 1958 2003 Muir Glacier 1941 2004 Glacier image archive available from NSIDC
  7. 7. Average mass balance of a few Arcticglaciers Arctic period 1 y = -6.7749 + 0.0033902x R= 0.23585 Arctic period 2 y = 43.522 - 0.02189x R= 0.81179 0.1 0 -0.1 Recent decades show less variability and -0.2 consistent negative trends. -0.3 -0.4 -0.5 1960 1970 1980 1990 2000 2010 Year Mass balance of Arctic glaciers show shift towards acceleration mass loss from 1988 (mass balance is in m of water equivalent)
  8. 8. Permafrost degradation Permafrost regions occupy 24% of the Siberia Northern Hemisphere and occur as far north as 84oN and as far south as 26oN in the Himalayas.
  9. 9. Increases in permafrost temperatureAlaskan permafrost temperatures, 20 m deep temperatures in the active layer Soil and upper permafrost Russian Permafrost Temperature 4 0.2 m; Trend = 0.78°C/decade 3 0.4 m; Trend = 0.79°C/decade 0.8 m; Trend = 0.65°C/decade 2 1.6 m; Trend = 0.55°C/decade Temperature Departure (°C) 3.2 m; Trend = 0.66°C/decade 1 0 -1 -2 -3 -4 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 Year • Alaska: 4 to 6oC increase in 20th Century, 2 to 3oC in last 30 years • Siberia: >3oC increase from mid-1950s to 1990 • Canadian Arctic: 1 to 3oC increase in past several decades • Tibetan Plateau:up to 1.0oC increase since 1970s Courtesy T. Zhang
  10. 10. Infrastructure impacts Chersky, Russia Alaska Alaska Qinghai-Xizang Highway bridge collapse Courtesy T. Zhang
  11. 11. Methane releasing from lakes Methane bubbles trapped in lake ice Lake bubbling with methane in the ArcticBurning methane over athermokarst lake in Siberia (K.Walter) Courtesy K. Walter
  12. 12. “Greening” of the Arctic Trends in vegetation synthetic activity from 1982–2005 (GIMMS-G AVHRR Vegetation indices) Significant positive trends Significant negative trends Courtesy S. Goetz, Woods Hole
  13. 13. Poster child of climate change: Arctic sea ice• Frozen surface of the ocean – Pancake Ice originates within ocean  Does not include land ice (glaciers, ice sheets)  Does not include other floating ice (ice shelves, icebergs)  If sea ice melts, sea level will not rise Multiyear Ice Ridged Ice NOAA Ice Floes
  14. 14. Just to be clear, sea ice is noticebergs! Courtesy Sebastian Copeland
  15. 15. Annual sea ice variability February Siberia Siberia Greenland Greenland Septemb erMaximum extent occurs in February/March (14-16 millionkm2 or 5-6 million square miles) , minimum extent occursin September (7-8 million km2 or about 3 million squaremiles)
  16. 16. Recent changes in Arctic sea ice• Previous studies have indicated a decline in annual Arctic sea ice cover since the late 1970s at a rate of -3%/decade or a loss in ice area of nearly 300,000 sq-km [e.g. Parkinson et al., 1999; Cavalieri et al., 1997; Bjorgo et al., 1997]. Current trend since 1979 is now at -4.3 % per decade
  17. 17. Losing the summer sea ice cover Time-series of September ice concentration during the modern satellite data record (1979 to 2010)
  18. 18. September 2007: A new recordminimum Alaska Stroeve et al. 2008
  19. 19. What caused the ice cover to drop in2007? • Unusual atmospheric circulation pattern that promoted warm temperatures and strong winds. June and July Sea Ice MotionTemperature Anomaly Strong ice drift away from A very Warm Arctic Siberian coast across the Arctic
  20. 20. What caused the ice cover to drop in2007? • Big culprit was a thin ice pack. Image courtesy of R. Kwok
  21. 21. Some recovery since 2007, but still indecline 1979-2000 2007 2008 2009Variability points to importance of summer circulation influence
  22. 22. Large changes in the distribution of iceage• Unfortunately we don’t have long-term records of Arctic-wide ice thickness measurements.• Tracking the age of the sea ice is one means to look a past thickness distribution, since older ice tends to be thicker. Spring 1986 Spring 1990 Spring 2007 Maslanik et al., 2007
  23. 23. Very little old ice left Only 320,000 km2 of ice 5+ years March Ice Age Distribution (Week 11) 8 7 6 Extent (million sq-km) 5 4 3 2 5+ winter extent 4 winter extent 3 winter extent 1 2 winter extent 1 winter extent 0 Year
  24. 24. Less than 60,000 km2 of 5+ ice left in September2010 End of Summer Ice Age Distribution 8 7 6 Extent (million sq-km) 5 4 3 2 1 0 Year • Less than 15% of the remaining ice is more than 2 years old, compared to 50-60% during the 1980s
  25. 25. Arctic sea routes opening upNW Passage opening up (2007-2010) NSR also open (2008-2010) Conditions in 2007 Conditions in 2008
  26. 26. Peering into the Future
  27. 27. Continued sea ice loss inevitable• Seasonally ice free Arctic sooner than we expect? Updated from Stroeve et al., 2007
  28. 28. Models suggest ice-free conditions may occurquickly• Climate models suggest once the sea ice cover is thinned sufficiently, a strong “kick” from natural variability can initiate a rapid slide towards ice-free conditions in summer [e.g. Holland et al., 2006]. September Sea Ice Extent 10 9 Model drop 1.8 million sq km, 2024–2025 8 Observed drop Ice Extent (million sq-km) 7 1.6 million sq km, 2006–2007 6 5 4 3 CCSM3 model 2 simulation Observations 1 0 1900 1920 1940 1960 1980 2000 2020 2040 2060 2080 2100
  29. 29. The set up looks right • Mean thickness (70-90N) in CCSM3 before abrupt change: 1.71 m • Mean thickness (70-90N) from ICESat in Spring 2007: 1.75 m (data from D. Yi and J. Zwally)
  30. 30. Increased Access to the Arctic
  31. 31. Today’s Arctic marine use Hard Minerals Maritime Tourism Major Fisheries Zinc & Coal Oil and Gas Summer Sea Lift Exploration/ScienceIn 2004 there were ~5500 ships Nickel & Copper High grade Iron Ore Snapshot of Summer 2004 Traffic ~ 5475 Ships
  32. 32. Distribution of known resourcesUSGS estimated in 2008 that 90 billion barrels of oil,1,700 trillion cubic feet of natural gas and 44 billionbarrels of natural gas liquids may be found in the Arctic,of which ~84% occurs offshore.Oil Gas
  33. 33. Impact on polar bears and other Arctic species
  34. 34. Polar bears under pressure• For every week a bear has not been hunting, it is 22 pounds lighter.  The bear’s reproductive system is strongly linked to their fat stores.• The offshore ice-based ecosystem is sustained by upwelling nutrients that feed the plankton, shrimp, and other small organisms, which feed the fish. These in turn feed the seals, which feed the bears.
  35. 35. Seals also feeling impacts• Lack of sea ice the last 2 years in the Gulf of St. Lawrence led to loss of thousands of baby harp seals.• Canada Fisheries reported that on the first day of spring 2010, there were only 600 seals in the gulf, when normally there are 30,000. Seal image courtesy Sebastian Copeland
  36. 36. Community impactsMany Arctic indigenous communities rely on sea ice fortravel and hunting, their main livelihood and basis for theircultural identityPhoto by Craig George
  37. 37. Impacts of changing sea ice on food resources• Reductions in sea ice are shrinking the marine habitat for ice- dependent seals, walrus, polar bears and some seabirds.• Sea-ice is thinner and now drifts far away during the summer, taking with it the seals, walrus and polar bears upon which the village’s Inuit residents rely for food. Courtesy S. Gearheardt
  38. 38. Safety issues• Changes in sea ice - local and regional thinning, unusual cracks, changes in the timing of break up and freeze up are already having a serious impact on travel safety.  Before venturing onto ice in fall or spring, hunters are encouraged to test its stability with a harpoon. Courtesy S. Gearheardt
  39. 39. Community locations threatened• Native communities are facing erosion problems and relocation of communities (at huge costs) as a result. Lack of sea ice cover exposes shoreline to waves and storms. Photo Craig George
  40. 40. Climate impacts for the rest of us Ice albedo feedback: ice edge retreat Sea ice in spring
  41. 41. Ice-Albedo Feedback-Amplifier of ClimateChange 1.0 Snow 0.8 Ice albedo feedback: 0.6 85% Albedo 0.4 7% 0.2 Ocean 0.0 Largest albedo to smallest
  42. 42. Arctic Amplification has already emerged Alaska Autumn (SON) air temperature anomalies: 2004- 2008 minus 1979- 2008 Updated from Serreze et al., 2008
  43. 43. Impact of sea ice loss on landtemperaturesPermafrost contains about 1672 Gt of carbon. Forcomparison, carbon content of Earth’s atmosphere: ~730 Gt today. Courtesy D. Lawrence
  44. 44. Results: Strength of the PCFCumulative NEE (Gt C) PCF Start 2023±4 Date (year) Paper in Tellus-B
  45. 45. Impacts on precipitation/snow cover• A warmer atmosphere changes atmospheric circulation and is able to hold more water vapor and thus could lead to more precipitation, especially in autumn and winter. Courtesy of Rutgers University Climate Lab
  46. 46. Final Statements• Many components of the Arctic environment are undergoing large changes.• Land and ocean ice loss in the Arctic is consistent with model simulations made with observed records of GHGs.• Sea ice loss is outpacing climate model projections, ice free summers by 2050?• Sea ice loss is already affecting the environmental, biological and societal systems in• the Arctic. ice loss will likely have significant Continued impacts beyond the Arctic.
  47. 47. •LearnMoreAboutClimate.Colorado.edu Climate Change and Colorado’s Future•New website that localizes climate change forColorado •Video series •Educator Resources •Scientists & citizens •Lesson plans & explain how climate resources to help bringchange is affecting our climate change to the state classroom •Plus resources to help citizens in making green choices

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