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Climate threat: what has changed, what could change Gustavo V. Necco

Climate threat: what has changed, what could change Gustavo V. Necco. UNICAMP 5 October 2004, Campinas, Brazil. Carbon dioxide levels rise - Mercury climbs Oceans warm – Glaciers melt – Sea level rises Sea ice thins – Permafrost thaws – Wildfires increase

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Climate threat: what has changed, what could change Gustavo V. Necco

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  1. Climate threat: what has changed, what could change Gustavo V. Necco UNICAMP 5 October 2004, Campinas, Brazil

  2. Carbon dioxide levels rise - Mercury climbs Oceans warm – Glaciers melt – Sea level rises Sea ice thins – Permafrost thaws – Wildfires increase Lakes shrink – Lakes freeze up later – Drought linger Ice shelves collapse – Precipitation increases Mountain streams run dry – Winter loses its bite Spring arrives earlier - Autumn comes later Plants flower sooner – Migration times vary Birds nets earlier – Diseases spread Coral reefs bleach – Habitats change Snow packs decline – Amphibians disappear Coastlines erode - Cloud forest dry Temperature spike at high latitudes GLOBAL CHANGE? GLOBAL “WARNING”? National Geographic, September 2004

  3. Global Change “Changes in the global environment (including alterations in the climate, land productivity, oceans or other water resources, atmospheric chemistry, and ecological systems) that may alter the capacity of the earth to sustain life.”

  4. Primary Contributors to the Natural Greenhouse Effect ~10% ~25% ~65% Increase in last century Carbon dioxide: 30 percent + Methane: 100 percent Nitrous oxide: 15 percent Halocarbons: ?

  5. The earth has a natural greenhouse effect due to trace amounts of H20 and CO2 that naturally occur. The enhanced greenhouse effect refers to the augmentation of these natural gases by human activities The net result is that we are depositing approximately 2 billion extra tons of carbon in an out of equilibrium cycle. Eventually this will be taken up by the land but the timescale for that process is unknown. Hence, the extra carbon, in the form of C02 remains in the atmosphere.

  6. * * G-8 * * * * *

  7. Vostok (Antarctica): 4 glacial cycles (Petit et al., 1999)

  8. Milankovitch (astronomic) factors

  9. Combined annual land-surface air and sea surface temperature anomalies (°C) 1861 to 2003, relative to 1961 to 1990. Two standard error uncertainties are shown as bars on the annual number.Hadley Center

  10. Global annual surface temperature anomalies Global annual surface temperature anomalies by hemisphere: a) NH, b) SH. Both were calculated with respect to the 1961-1990 period. BAMS, Vol. 85, N° 6, June 2004

  11. Global mean annual temperature over the past 2 millenia Reconstructions of NH global mean annual temperatures over the past two millennia. Expansion compares a number of different estimates over the past 1000 years. Smoothed (40- year low passed) versions are shown to highlight low-frequency variations. Jones & Mann, Reviews of Geophysics, Vol. 42, N° 2, June 2004

  12. Global map of temperature anomalies for the 2002 meteorological year (Dec. 2001-Nov. 2002) relative to the 1951-1980 baseline NASA/GISS

  13. Regional trends of surface temperature minus lower tropospheric temperatures (°C/decade). Surface temperatures are from IPCC (2001) and lower tropospheric temperatures from Christy et al. (2000). UNDERSTANDING RECENT ATMOSPHERIC TEMPERATURE TRENDS AND REDUCING UNCERTAINTIES In support of Chapter 3 of the Strategic Plan for the Climate Change Science Program Draft dated 26 November 2002

  14. Annual global temperature departures (1999 value based on 8 month mean) World Climate Report

  15. Changes in intense NH winter storms and temperatures correlate well

  16. Africa Changes in the number of warm days. Dark circles represent warming and white circles cooling. From Easterling et al., 2003 Trends (% time/decade)

  17. Precipitation has increased in some parts of the world and decreased in others Trends (%/century) in annual precipitation for 1900-2000 Insert figure

  18. Permafrost (perennially frozen ground) Permafrost temperatures at depths of 11.5 m and 19.5 m, Murtel Corvatsch (Swiss Alps) 1987-2002 (Harris & Haeberli, 2003)

  19. This image illustrates the rapid thinning of the GreenlandIce Sheet as measured by NASA's Airborne Topographic Mapper. NASA´s scientific visualization studio

  20. Sea-ice extent Monthly anomalies (millions of km2) of Arctic and Antarctic sea-ice extent for the period 1973-2001, derived from satellite passive microwave sounder data (Source: HadlSST1 data set, Hadley Centre, UK Met Office) Trend : - 2.8 % per decade

  21. Antarctic sea ice decline since the 50s (M.A.J. Curran et all., Science, Vol.302, 14 Nov. 2003) MSA: Methanesulphonic acid SIE: Sea ice extent for the 80E to 180E sector (satellite derived) Trend: 20% decline in SIE since about 1950

  22. Sea Ice Extent NH 20th Century Time series of annual and seasonal sea ice extent in the Northern Hemisphere, 1901-2003 (Annual values from Vinnikov et al. 1999, seasonal values courtesy of B. Chapman, update from Chapman and Walsh, 1993) BAMS, Vol. 85, N° 6, June 2004

  23. a 1979-90 b 1991-2002 c 2003 ICE CONCENTRATION d d=(b-a) Ice concentrations at their minimum summertime levels. Panels a and b display the average minima recorded during 1979-90 and 1991-2002, respectively. Panel c in 2003. Panel d = difference (b-a) Average size of ice pack in 1979-90 > 1991-2002 by 12%. The Beaufort Sea has suffered the most substantial reduction of ice. J. F. Comiso & C.L. Parkinson Physics Today, August 2004 ICE CONCENTRATION CHANGE

  24. Arctic ice, ocean and atmosphere are closely interconnected: a change to one influences the others. a): One possible feedback loop b): Some of the key fluxes that affect the Arctic system. The arrows overlay a satellite-derived map of the perennial ice cover when the cover was least extensive in 2002 J. F. Comiso & C.L. Parkinson Physics Today, August 2004

  25. Melting glaciers Athabasca glacier in 1917 and 1986. Climate change could result in significant retreat of large glaciers such as this, and related reduction in downstream water flows, wildlife habitat, and hydroelectricity production Alberta/BC Provincial Boundary Commission B.H. Luckman

  26. Kilimanjaro 1970

  27. Photos: L. Thompson Kilimanjaro 2000

  28. Kilimanjaro 2020? Area (km2) L.Thompson et al. 2002

  29. Global Mean Sea-level Change Global averaged sea-level change between January 1950 and December 2000 from reconstructions, and the global mean sea-level from the TOPEX/Poseidon satellite altimeter (top panel). Estimated regional distribution of sea-level rise between January 1950 and December 2000 (bottom panel). The solid line is 2 mm yr-1, and the contour interval is 0.5 mm yr-1 J. A. Church et al. BAMS, Vol. 85, N° 7, July 2004

  30. Bering Sea - + - - - - Monthly temperatures anomalies (left) at St. Paul Island as a function of month and year. The base period is 1961-1990. Note the shift towards warmer temperatures both after 1976 and for the previous 4 years, Concentration (% cover) of sea ice over the southeastern Bering Sea between latitudes 57°N and 58°N (right). Location chart al lower right J. E. Overland & P.J. Stabeno EOS, Vol. 85, N° 33, 17 August 2004

  31. Bering Sea The evolution of depth-averaged sea temperatures from an oceanographic mooring at site M2 (56.8°N, 164°W) for spring and summer in different years (Stabeno et al., 2002) J. E. Overland & P.J. Stabeno, EOS, Vol. 85, N° 33, 17 August 2004

  32. Bering Sea Spawning biomass (diamonds) and recruitment (yearly addition in millions of fish to the stock) for representative Bering fish: Greenland turbot and flathead sole. Data from the National Marine Fisheries Services (North Pacific Fishery Management Council, 2003) J. E. Overland & P.J. Stabeno EOS, Vol. 85, N° 33, 17 August 2004

  33. 100% 80% 60% C. finmarchicus 40% 20% C. helgolandicus 12 0% 11 1992 10 9 8 7 months 6 5 4 3 2 Calanus helgolandicus Calanus finmarchicus 1 60 65 70 75 80 85 90 95 60 65 70 75 80 85 90 95 2. Biodiversity changes has resulted in species replacements 1982 1972 1962 3. Replacement of similar species but with different seasonal abundances has dramatic consequences for the dynamics of the food web 1962 1964 1966 1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 1. Changes in the circulation in the N. Atlantic over the last 50 years has affected biodiversity

  34. Key species in the North Atlantic Calanus finmarchicus • Up to 80-90% of copepod biomass, and a major herbivore throughout the sub-arctic North Atlantic. • Important prey species in both shelf and ocean ecosystems – especially for cod! • Cod populations (juveniles) dependent upon it as a primary food source

  35. Heath et al. 1999. Climate fluctuations and the spring invasion of the North Sea by Calanus finmarchicus. Fisheries Oceanography. 8(1):163-176

  36. Fisheries: Vilcinskas 2000

  37. atmosphere cryosphere hydrosphere lithosphere biosphere anthroposphere human decisions and actions GEC deals with the Earth system “in toto”: Ecosphere + the human factor Ecosphere Human factor

  38. The Earth System: Coupling the Physical, Biogeochemical and Human Components / DIVERSITAS

  39. Atmosphere Models The Earth System Unifying the Models Climate / Weather Models Carbon Cycle and Biogeochemistry Water Cycle The Predictive Earth System Hydrology Process Models Ocean Models Land Surface Models Natural Hazard Prediction Terrestrial Biosphere Models Solid Earth Models Gigaflops Teraflops Petaflops Megaflops 2000 2010

  40. Coupling AGCMs to OGCMs is a complex process

  41. IPCC, TAR, 2001

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