Transcript Fisheries and Climate Change: the IPCC Second Assessment

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
[email protected]
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)
Intergovernmental Panel
on CC
• Mission: provide an authoritative statement
of scientific opinion on CC
• Broadly peer reviewed plus govm’t review
• Several hundred scientists serve on WG’s
•science of climate change itself
•impacts and response strategies
•broad socioeconomic issues
Fisheries Lead Authors
Dr. John T. Everett, CLA
Dr. Daniel Lluch Belda
Washington, USA
La Paz, BCS, Mexico
Dr. Andre Krovnin
Dr. Henry A. Regier
Moscow, Russia
Toronto, Canada
Dr. Ezekiel Okemwa
Jean-Paul Troadec
Mombasa, Kenya
Brest, France
The Culprits
Source: IPCC 2001
Physical Changes
• Climate change will come with changes in
• temperature,
• circulation,
• sea level,
• ice coverage,
• wave climate, and
• extreme events,
• Affecting ecosystem structure & function
Temperature
• Obs: 1998 was hottest year in 1000. “Global average
land and ocean temperature was the warmest on
record for January (NOAA CDC 2002)”
• Proj: Ave. temp. to increase 1.4-5.8° 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
Temperatures are Rising - Recently
Source: IPCC 2001
Temperatures are Rising
Source: IPCC 2001
Warming is Uneven
Source: IPCC 2001
7 of 9 Models Agree on Warmer
Winters & Summers in Northeast
Source: IPCC 2001
Currents & Upwelling
• Proj: A weakening of the global thermohaline 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
Ocean Conveyer Belt
Source: US National Assessment
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
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
Sea Level Rise
• Obs. show 10-25 cm. rise since 1900; 1-2 mm/yr.
10X faster than previous 3K yrs. No acceleration
detected
• Proj. is +11 - 77 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
The Oceans are Rising
Source: IPCC 2001
Armored Coasts
Precipitation
• Obs show several %/decade greater air
moisture & precip up 1%/decade in midhigh latitudes
• Proj: A few percent increase
• More extreme, heavier precip events
• This can affect water salinity, watershed
flows, turbidity, pollutant loading and
related factors
7 of 9 Models Agree on Wetter
Winters in Northeast
Source: IPCC 2001
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
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
Societal Sensitivities
• Species in more stable environments are
usually more valuable
• Fishers can follow fish, communities won’t
• Political borders or economics stop pursuit
• Developing nations dependent on fish as
food or export earnings are most sensitive
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
Societal
• Temperatures above or below the stock’s 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
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
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 50-100 years.
CC Impact Ranking
for Fisheries
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
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)
Understanding Requires a Broad View
Oceanwide Synchrony in Pacific Sardines and the North Pacific Index
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).
700
Peru/Chile
600
7
6
5
500
California
4
400
3
300
2
200
100
Japan
1
0
0
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
Sources: U.S. GLOBEC, FAO 1998
North Pacific Index (Atmos. Pressure)
Japan and Peru/Chile Sardine Catch
(Thousand Metric Tons)
Negative
NPI
(Million Metric Tons)
California Sardine Catch
800
Negative
NPI
What comes first?
Where to get Information
•Intergovernmental Panel on Climate Change (IPCC): www.ipcc.ch/
•NMFS Pacific Fisheries Env Lab www.pfel.noaa.gov/research/climatemarine/
•U.S. Environmental Protection Agency (EPA): www.epa.gov/globalwarming
•U.S. Global Change Research Program (USGCRP): www.usgcrp.gov
•UN Atlas of the Oceans: www.oceansatlas.org
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: ScientificTechnical 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 www.usgcrp.gov
IPCC Working Group I, 2001. Climate Change 2001: The Scientific Basis. Document of
the Intergovernmental Panel on Climate Change www.usgcrp.gov