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Oceans and Climate Change: What We Think We Know Dr. John T. Everett Project Manager, United Nations Atlas of the Oceans Former IPCC Convening Lead Author.

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Presentation on theme: "Oceans and Climate Change: What We Think We Know Dr. John T. Everett Project Manager, United Nations Atlas of the Oceans Former IPCC Convening Lead Author."— Presentation transcript:

1 Oceans and Climate Change: What We Think We Know Dr. John T. Everett Project Manager, United Nations Atlas of the Oceans Former IPCC Convening Lead Author (SAR) - Fisheries Former Director, Division of Research, NOAA/NMFS Ocean Associates Oceans and Fisheries Consulting 4007 North Abingdon Street Arlington, Virginia, USA

2 This Presentation Is based largely on the IPCC 1995 Report; Fisheries - Chapter 16. It is valid and best available The 2001 IPCC report of impacts is by region. There is little information specifically on marine fisheries The 2001 US National Assessment does not treat marine fisheries in depth (USNA) Physical changes reflect the 2001 IPCC report (IPCC 2001)

3 Intergovernmental Panel on CC Mission: provide an authoritative statement of scientific opinion on CC Broadly peer reviewed plus govmt review Several hundred scientists serve on WGs science of climate change itself impacts and response strategies broad socioeconomic issues

4 Fisheries Lead Authors Dr. John T. Everett, CLA Dr. Daniel Lluch Belda Washington, USALa Paz, BCS, Mexico Dr. Andre KrovninDr. Henry A. Regier Moscow, Russia Toronto, Canada Dr. Ezekiel OkemwaJean-Paul Troadec Mombasa, KenyaBrest, France

5 The Culprits Source: IPCC 2001

6 Physical Changes Climate change will come with changes in temperature, circulation, sea level, ice coverage, wave climate, and extreme events, Affecting ecosystem structure & function

7 Temperature Obs: 1998 was hottest year in Global average land and ocean temperature was the warmest on record for January (NOAA CDC 2002) Proj: Ave. temp. to increase ° C by 2100 High n. latitudes warm more than average Nights (2X) & winters warm more than average Ocean changes lag land by 10 years Exceptions: delay or cooling in belt around Antarctica and in high N. Atlantic In high latitudes, the growing period and productivity should increase

8 Temperatures are Rising - Recently Source: IPCC 2001

9 Temperatures are Rising Source: IPCC 2001

10 Warming is Uneven Source: IPCC 2001

11 7 of 9 Models Agree on Warmer Winters & Summers in Northeast Source: IPCC 2001

12 Currents & Upwelling Proj: A weakening of the global thermo- haline circulation may occur, reducing heat transport to the N. Atlantic Competing arguments on oceanic & coastal upwelling increase or decrease No reliable forecasts Forces driving natural variability not well understood

13 Ocean Conveyer Belt Source: US National Assessment

14 Storms and El Niño Obs: No trends in storminess in last 50 years. Some regional trends in storminess in both directions The post 1989 period of ENSO activity seems unusually high, but may have happened before Proj: Changes in frequency & intensity of cyclones, storms, & El Niño uncertain

15 Ice Cover Obs: Two weeks less fresh ice in last ~125 yrs. No evident trend in sea ice in Antarctic. Proj: Glaciers and snow and ice coverage to continue retreat in N. hemisphere. Major loss of fresh & sea ice The NW Passage & N. Sea Route of Russia may have 100 days of shipping. 40% thinner summer Arctic ice since ~1960 In the Antarctic, the main effect will be a retreat of the ice edge Ice coverage impacts ice-associated species, primary productivity, fishing and aquaculture

16 Sea Level Rise Obs. show cm. rise since 1900; 1-2 mm/yr. 10X faster than previous 3K yrs. No acceleration detected Proj. is cm by 2100; from thermal expansion & melting of ice. USNA*: +19 by 2100 Regional variations due to wind and atmospheric pressure, ocean density, land motion, currents Wetlands will decrease; sharply where there is shore protection Higher wave energy; faster erosion *USNA= US National Assessment

17 The Oceans are Rising Source: IPCC 2001

18 Armored Coasts

19 Precipitation Obs show several %/decade greater air moisture & precip up 1%/decade in mid- high latitudes Proj: A few percent increase More extreme, heavier precip events This can affect water salinity, watershed flows, turbidity, pollutant loading and related factors

20 7 of 9 Models Agree on Wetter Winters in Northeast Source: IPCC 2001

21 UV-B Other groups, not IPCC, study ozone depletion Obs: ozone losses up in mid-latitudes & Arctic Growth rates of several problem chemicals have slowed or stopped. Peak may be past Proj: ozone layer may return to normal about 2050 In clear waters, UV-B penetrates tens of meters, damaging eggs, larvae and zooplankton In coastal waters, less than 1 meter Antarctic ozone hole is larger than Antarctica

22 Species Sensitivities Changes: temperature, sea level, river flows, salinity, currents, winds, storms, and variability Species are dependent on one or more of above Species can move rapidly if habitat and paths exist Fish are cold-blooded. Life processes, like growth, are faster when warmer (within limits) Many species have narrow ecological niches, but there are many species to fill niches Small changes cause large disruptions to a species Mixes will change until stability is reestablished

23 Societal Sensitivities Species in more stable environments are usually more valuable Fishers can follow fish, communities wont Political borders or economics stop pursuit Developing nations dependent on fish as food or export earnings are most sensitive

24 Sensitivity Examples Scallop and fish eggs that rely on a gyre to return them to their habitat on a certain day or week Fish eggs in streams or on the sea floor that require a minimum current speed for oxygenation Species that require an influx of freshwater to induce spawning or to kill predators Temperatures above or below the stocks lethal limit Immobility of communities dependent on one species Societies without money to buy other foods Fishers unable to deal with new vessel/gear demands Species Societal


26 Important Findings Freshwater fisheries and aquaculture at mid to higher latitudes should benefit Saltwater fisheries should be about the same Fishery areas and species mix will shift Changes in abundance more likely near ecosystem boundaries National fisheries will suffer if fishers cannot move within and across national borders Subsistence/small scale fishermen suffer most

27 Important Findings-2 CC impacts add to overfishing, lost wetlands and nurseries, pollution, UV-B, and natural variation Inherent instability in world fisheries will be exacerbated by a changing climate Globally, economic and food supply impacts should be small. Nationally, they could be large Overfishing is more important than CC today; the relationship should reverse in years.

28 1. Small rivers and lakes, in areas of higher temperatures and less rain 2. Within EEZs, particularly where fishers cannot follow migrating fish 3. In large rivers and lakes 4. In estuaries 5. High seas CC Impact Ranking for Fisheries

29 Adaptation Options Establish management institutions that recognize shifting distributions, abundances and accessibility, and that balance conservation with economic efficiency and stability Support innovation by research on management systems and aquatic ecosystems Expand aquaculture to increase and stabilize seafood supplies and employment, and carefully, to augment wild stocks Integrate fisheries and CZ management Monitor health problems (e.g., red tides, ciguatera, cholera)

30 California Sardine Catch (Thousand Metric Tons) Japan and Peru/Chile Sardine Catch (Million Metric Tons) Peru/Chile California Japan Historical catches in the sardine fisheries of Japan, California and Peru-Chile exhibit parallel patterns, possibly in response to global-scale changes in climate (modified from Kawasaki, 1992). Understanding Requires a Broad View Oceanwide Synchrony in Pacific Sardines and the North Pacific Index Negative NPI What comes first? Sources: U.S. GLOBEC, FAO 1998 North Pacific Index (Atmos. Pressure)

31 Where to get Information Intergovernmental Panel on Climate Change (IPCC): NMFS Pacific Fisheries Env Lab U.S. Environmental Protection Agency (EPA): U.S. Global Change Research Program (USGCRP): UN Atlas of the Oceans: Primary References Everett, J.T., E. Okemwa, H.A. Regier, J.P. Troadec, A. Krovnin, and D. Lluch-Belda, 1995: Fisheries. In: The IPCC Second Assessment Report, Volume 2: Scientific- Technical Analyses of Impacts, Adaptations, and Mitigation of Climate Change (Watson, R.T., M.C. Zinyowera, and R.H. Moss (eds.)]. Cambridge University Press, Cambridge and New York, 31 pp. National Assessment Synthesis Team, 2001: Climate Change Impacts on the United States; The Potential Consequences of Climate Variability and Change Foundation. US Global Change Research Program, Washington IPCC Working Group I, Climate Change 2001: The Scientific Basis. Document of the Intergovernmental Panel on Climate Change

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