Written
Statement By
DR.
JOHN T. EVERETT
HEARING ON
WILDLIFE
AND OCEANS IN A CHANGING CLIMATE
BEFORE THE
COMMITTEE ON NATURAL
RESOURCES
SUBCOMMITTEE ON
FISHERIES, WILDLIFE AND OCEANS
U.S. HOUSE OF
REPRESENTATIVES
April 17, 2007
Madam Chairwoman and Members of
the Committee, thank you for inviting me to appear before you today. I am John
Everett. I am not here to represent any particular organization, company, nor
special-interest group. I have never received any funding to support my climate
change work other than my NOAA salary, when I was employed there up to five
years ago, in various positions over a 31 – year career. I will present
the results of the work I led for the Intergovernmental Panel on Climate Change
from 1988 to 2000, while an employee of NOAA. This is still the most thorough,
comprehensive, and broadly reviewed work on the subjects that has been
published. The reports were reviewed by hundreds of government and academic
scientists as part of the IPCC process. My work included five impact analyses:
Fisheries (Convening Lead Author), Polar Regions (Co-Chair), Oceans (Lead
Author), and Oceans and Coastal Zones (Co-Chair/2 reports). Since leaving NOAA
I have kept abreast of the literature, have talked to many individuals and
groups and have maintained these subjects in the UN Atlas of the Oceans, where
I am the Chief Editor and Project Manager. While I will present the results
from IPCC documents I led or helped write, all opinions are mine alone, and are
at the end.
I was assigned the climate change duties when I was the
National Marine Fisheries Service Division Chief for Fisheries Development in
the 1970s. The agency was very concerned about the impact of climate change on
the United States fisheries and fishing industry. Global cooling. would be devastating to our fisheries and
aquaculture. About 1987, the momentum shifted to fears of global
warming and with my background, I was
tasked to lead our efforts dealing with it. In 1996 I received the NOAA
Administrator’s Award for “accomplishments in assessing the impacts of climate
change on global oceans and fisheries.”
Taking
only information from IPCC reports, essentially verbatim, I first present a
summary, then more detail. The full reports are listed in the endnotes and have
all the supporting text (about 60 pages) and hundreds of citations, which do
not appear here.
Fisheries
·
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)
·
Climate change 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. In some countries, they could
be large
·
Overfishing is more important than climate change
today; the relationship should reverse in 50-100 years (as overfishing is
controlled)
Oceans
·
Temperature changes will cause geographical shifts in
biota and changes in biodiversity, and in polar regions the extinction of some
species and proliferation of others.
·
A temperature rise in high latitudes should increase
the duration of the growing period and the productivity of these regions.
·
Increased coral bleaching will occur as a result of a
predicted 2°C increase in average global atmospheric temperature by 2050.
·
The Northwest Passage and Northern Sea Route of Russia
likely will be opened for routine shipping.
·
Sea-level changes will occur with regional variations.
·
Changes in coastal pollutants will occur with changes
in precipitation and runoff.
·
Changes in circulation and vertical mixing will
influence nutrient availability and primary productivity, affecting the
efficiency of carbon dioxide uptake by the oceans.
·
The oceans’ uptake and storage capacity for greenhouse
gases will be affected by changes in nutrient availability resulting from other
changes in precipitation, runoff, and atmospheric deposition.
·
Freshwater influx from movements and melting of sea ice
or ice sheets may lead to a weakening of the global thermohaline circulation,
causing unpredictable instabilities in the climate system.
·
Reduced yields of desirable fish species will occur if
primary productivity decreases.
·
Marine mineral extraction, except for petroleum
hydrocarbons and the marine pharmaceutical and biotechnological industries, is
insensitive to global climate change.
Polar Regions
·
Major physical, ecological, sociological, and economic
changes are expected in the Arctic, but much smaller changes are likely for the
Antarctic.
·
Substantial loss of sea ice is expected in the Arctic
ocean. If there is more open water, there will be a feedback to the climate
system of northern countries by moderating temperature and increasing
precipitation.
·
Polar warming probably should increase biological production,
but may lead to different species composition. In the sea, marine ecosystems
will move poleward. Animals dependent on ice may be disadvantaged.
·
Human communities in the Arctic will be affected by the
physical and ecological changes. Effects will be particularly important for
indigenous peoples leading traditional lifestyles.
·
There will be economic benefits and costs. Benefits
include new opportunities for shipping across the Arctic Ocean, lower
operational costs for the oil and gas industry, lower heating costs, and easier
access for tourism. Increased costs can be expected from several sources
including disruptions caused by thawing of permafrost and reduced
transportation capabilities across frozen ground and water.
·
Sea ice changes in the Arctic have major strategic
implications for trade and defense.
The oceans and coastal zones have been far warmer and colder
than is projected in the present scenarios of climate change. Marine life has
been in the oceans nearly since when they were formed. During the millennia
they endured and responded to CO2 levels well beyond anything projected, and
temperature changes that put tropical plants at the poles or had much of our
land covered by ice more than a mile thick. The memory of these events is built
into the genetic plasticity of the species on this planet. IPCC forecasts are
for warming to occur faster than evolution is considered to occur, so impacts
will be determined by this plasticity and the resiliency of affected organisms
to find suitable habitats. In the oceans, major climate warming and cooling is
a fact of life, whether it is over a few years as in an El Niño or over decades
as in the Pacific Decadal Oscillation or the North Atlantic Oscillation.
Currents, temperatures, salinity, and biology changes rapidly to the new state
in months or a couple years. These changes far exceed the changes expected with
global warming and occur much faster. The one degree F. rise since 1860 is
virtually noise in this rapidly changing system. Sea level has been inexorably
rising since the last glaciation lost its grip a mere 10,000 years ago. It is
only some few thousand years since trees grew on Georges Bank and oysters
flourished on its shores. Their remains still come up in dredges and trawls in
now deep water, with the oysters looking like they were shucked yesterday. In
the face of all these natural changes, and those we are here to consider, some
species flourish while others diminish. These considerations were well
understood in all the IPCC groups in which I participated.
The following text is taken from IPCC reports that I led.
The text is left intact, with a very few edits to make complete sentences after
deletion of portions irrelevant for this Hearing, such as some terrestrial
impacts in the Arctic. Most background information has been deleted, but all
these summary statements are fully supported in the cited references.
Convening Lead Author:
John T. Everett, USA. Lead Authors:
A. Krovnin, Russia; D. Lluch-Belda, Mexico; E. Okemwa, Kenya; H.A. Regier,
Canada; J.-P. Troadec, France
Summary. Climate-change effects interact with those of
pervasive overfishing, diminishing nursery areas, and extensive inshore and
coastal pollution. Globally, marine fisheries production is expected to remain
about the same; high-latitude freshwater and aquaculture production are likely
to increase, assuming that natural climate variability and the structure and
strength of ocean currents remain about the same. The principal impacts will be
felt at the national and local levels as species mix and centers of production
shift. The positive effects of climate change—such as longer growing
seasons, lower natural winter mortality, and faster growth rates in higher
latitudes—may be offset by negative factors such as changes in
established reproductive patterns, migration routes, and ecosystem
relationships.
• Globally, under
the IPCC scenarios, saltwater fisheries production is hypothesized to be about
the same, or significantly higher if management deficiencies are corrected.
Also, globally, freshwater fisheries and aquaculture at mid- to higher
latitudes could benefit from climate change. These conclusions are dependent on
the assumption that natural climate variability and the structure and strength
of wind fields and ocean currents will remain about the same. If either
changes, there would be significant impacts on the distribution of major fish
stocks, though not on global production (Medium Confidence).
• Even without
major change in atmospheric and oceanic circulation, local shifts in centers of
production and mixes of species in marine and fresh waters are expected as
ecosystems are displaced geographically
and changed internally. The relocation of populations will depend on properties being present in the changing environments to shelter all stages of
the life cycle of a species (High Confidence).
• While the complex
biological relationships among fisheries and other aquatic biota and
physiological responses to environmental change are not well understood,
positive effects such as longer growing seasons, lower natural winter
mortality, and faster growth rates in higher latitudes may be offset by negative factors such as a changing
climate that alters established reproductive patterns, migration routes, and
ecosystem relationships (High Confidence).
• Changes in
abundance are likely to be more pronounced near major ecosystem boundaries. The
rate of climate change may prove a major determinant of the abundance and
distribution of new populations. Rapid change due to physical forcing will
usually favor production of smaller,
low-priced, opportunistic species that discharge large numbers of eggs over
long periods (High Confidence). However, there are no compelling data to
suggest a confluence of climate-change impacts that would affect global
production in either direction, particularly because relevant fish population
processes take place at regional or smaller scales for which general
circulation models (GCMs) are insufficiently reliable.
• Regionally,
freshwater gains or losses will depend on changes in the amount and timing of
precipitation, on temperatures, and on species tolerances. For example,
increased rainfall during a shorter period in winter still could lead to
reduced levels in summer in river
flows, lakes, wetlands, and thus in freshwater fisheries. Marine stocks that
reproduce in freshwater (e.g., salmon) or require reduced estuarine salinities
will be similarly affected (High Confidence).
• Where ecosystem
dominances are changing, economic values can be expected to fall until
long-term stability (i.e., at about present amounts of variability) is reached
(Medium Confidence). National fisheries will suffer if institutional mechanisms
are not in place that enable fishing
interests to move within and across national boundaries (High Confidence).
Subsistence and other small-scale fishermen, lacking mobility and alternatives,
often are most dependent on specific fisheries and will suffer
disproportionately from changes (Medium Confidence).
• Because natural variability is so great relative to
global change, and the time horizon on capital replacement (e.g., ships and
plants) is so short, impacts on fisheries can be easily overstated, and there
will likely be relatively small economic and food supply consequences so long
as no major fish stocks collapse (Medium
Confidence).
• An impact ranking
can be constructed. The following items will be most sensitive to environmental
variables and are listed in descending order of sensitivity (Medium Confidence):
– Freshwater fisheries in
small rivers and lakes, in regions with larger temperature and precipitation
change
– Fisheries within
Exclusive Economic Zones (EEZs), particularly where access-regulation
mechanisms artificially reduce the mobility of fishing groups and fleets and
their capacity to adjust to fluctuations in stock distribution and abundance
– Fisheries in large
rivers and lakes
– Fisheries in estuaries,
particularly where there are species without migration or spawn dispersal paths
or in estuaries impacted by sea-level rise or decreased river flow
– High-seas fisheries.
• Adaptation
options with large benefits irrespective of climate change (Medium Confidence):
– Design and implement
national and international fishery-management institutions that recognize
shifting species ranges, accessibility, and abundances and that balance species
conservation with local needs for economic efficiency and stability
– Support innovation by
research on management systems and aquatic ecosystems
– Expand aquaculture to
increase and stabilize seafood supplies, help stabilize employment, and
carefully augment wild stocks
– In coastal areas,
integrate the management of fisheries with other uses of coastal zones
– Monitor health problems
(e.g., red tides, ciguatera, cholera) that could increase under climate change and harm fish stocks and consumers.
Convening Lead Author:
Venugopalan Ittekkot, Germany. Principal Lead Authors: Su Jilan, China; E. Miles, USA; Lead Authors: E.
Desa, India; B.N. Desai, India; J.T. Everett, USA; J.J. Magnuson, USA; A.
Tsyban, Russian Federation; S. Zuta, Peru
Summary. Global warming as projected by Working Group I of
the IPCC will have an effect on sea-surface temperature and sea level. As a
consequence, it is likely that ice cover and oceanic circulation will be
affected, and the wave climate will change. The expected changes affect global
biogeochemical cycles, as well as ecosystem structure and functions, on a wide
variety of time and space scales; however, there is uncertainty as to whether
extreme events will change in intensity and frequency. We have a high level of
confidence that:
• Redistribution
of temperatures could cause geographical shifts in biota as well as changes in
biodiversity, and in polar regions the extinction of some species and
proliferation of others. A rise in mean temperature in high latitudes should
increase the duration of the growing period and the productivity of these
regions if light and nutrient conditions remain constant.
• Sea-level
changes will occur from thermal expansion and melting of ice, with regional
variations due to dynamic effects resulting from wind and atmospheric pressure
patterns, regional ocean density differences, and oceanic circulation.
• Changes
in the magnitude and temporal pattern of pollutant loading in the coastal ocean
will occur as a result of changes in precipitation and runoff.
We
can say with a lesser degree of confidence that:
• Changes
in circulation and vertical mixing will influence nutrient availability and
primary productivity, thereby affecting the efficiency of carbon dioxide uptake
by the oceans.
• The oceans’
uptake and storage capacity for greenhouse gases will be affected further by
changes in nutrient availability in the ocean resulting from other changes in
precipitation, runoff, and atmospheric deposition.
• Freshwater
influx from the movements and melting of sea ice or ice sheets may lead to a
weakening of the global thermohaline circulation, causing unpredictable
instabilities in the climate system.
The most pervasive effects of global climate
change on human uses of the oceans will be due to impacts on biotic resources;
transportation and nonliving resource exploitation will be affected to a lesser
degree. We can say with a high level of confidence that:
• Increased
coral bleaching will occur as a result of a predicted 2°C increase in average
global atmospheric temperature by 2050.
• Expanded
dredging operations will be necessary to keep major ports open in the Northern
Hemisphere, which will increase costs.
• The
Northwest Passage and Northern Sea Route of Russia likely will be opened up for
routine shipping.
• Growth
in the marine instrumentation industry will occur as the need for research and
monitoring of climate change increases.
We
can say with a lesser degree of confidence that:
• Reduced
yields of desirable fish species will occur if average primary productivity
decreases.
• If the frequency
of tropical storms and hurricanes increases, adverse impacts will be generated
for offshore oil and gas activities and for marine transportation in the
tropics.
• Marine mineral
extraction, except for petroleum hydrocarbons and the marine pharmaceutical and
biotechnological industries, is insensitive to global climate change.
Adaptation
to the impact of climate change on oceans is limited by the nature of these
changes, and the scale at which they are likely to occur:
• No
adaptive responses to coral bleaching, even on a regional scale, will be
available if average global temperature increases 2°C by 2050. However, reductions
in land-based pollution of the marine environment, combined with reductions in
habitat degradation/ destruction, would produce benefits for fisheries,
aquaculture, recreation, and tourism.
• Adaptation
options will be available for the offshore oil, gas, and shipping industries if
the frequency of tropical storms and hurricanes increases. The options include
improved design standards for offshore structures, national and international
regulations for shipping, and increased technological capabilities to provide
early warning at sea. Governments also can increase attention to institutions
for planning and responding to disasters and emergencies.
• Where climate
change generates positive effects, market-driven needs will create their own
adaptation dynamic. However, adaptation policies will be required to control
externalities that are market failures. For instance, opening up both the
Northwest Passage and the Russian Northern Sea Route for up to 100 days a
year—while a boon to international shipping and consumers in East Asia,
North America, and Western Europe—will have to be accompanied by policies
designed to limit the total burden of pollutants entering the Arctic
environment from ports, ship operations, and accidents.
A combination of
human activities (e.g., overfishing, pollution of estuaries and the coastal
ocean, and the destruction of habitat, especially wetlands and seagrasses)
currently exerts a far more powerful effect on world marine fisheries than is
expected from climate change.
In contrast to
model projections, observations over large parts of the tropical Atlantic
between 1947 and 1986 have shown an increase in the trade winds. Bakun suggests
that the greenhouse effect will enhance the seasonal warming of
continents—leading to a decrease in the pressure over land, an increase
in the land–sea pressure difference, and increased alongshore winds.
Binet has observed such effects along the coast of northwest Africa. It appears
likely that the strength of both oceanic and coastal upwelling mechanisms could
change under conditions of global warming, with profound impacts upon fish
species and their production as well as on the climate of the immediate coastal
zone.
Although ENSO is
a natural part of the Earth’s climate, a major question is whether the
intensity or frequency of ENSO events might change as a result of global
warming. Historical and paleorecords reveal that ENSO events have changed in
frequency and intensity in the past on multidecadal to century timescales. It
is unclear whether ENSO might change with long-term global warming.
Sea ice covers
about 11% of the ocean, depending on the season. It affects albedo, salinity,
and ocean-atmosphere thermal exchange. The latter determines the intensity of
convection in the ocean and the timescale of deep-ocean processes affecting CO2 uptake and storage.
Projected
changes in climate should produce large reductions in the extent, thickness,
and duration of sea ice. Major areas that are now ice-bound throughout the year
are likely to have major periods during which waters are open and navigable.
Some models even predict an ice-free Arctic. Melting of snow and glaciers will
lead to increased freshwater influx, changing the chemistry of those oceanic
areas affected by the runoff. There is no convincing evidence of changes in the
extent of global sea ice. Studies on regional changes in the Arctic and
Antarctic indicate trends of decadal length, often with plausible mechanisms
proposed for periodicities of a decade or more. Longer data sets are needed to
test if a genuine long-term trend is developing.
Winds and waves
are the major forcing factors for vertical mixing; the degree of mixing depends
on the vertical density structure. In the past 40 years, there has been an
increase in the mean wave height over the whole of the North Atlantic, although
it is not certain that global change is the cause of this phenomenon.
Metabolic rates,
enzyme kinetics, and other biological characteristics of aquatic plants and
animals are highly dependent on external temperatures; for this reason alone,
climate change that influences water temperature will have significant impacts
on the ecology and biodiversity of aquatic systems. The capability of some
species to adapt genetically to global warming will depend on existing genetic
variation and the rapidity of change. Species remaining in suboptimal habitats
should at least experience reductions in abundance and growth well before
conditions become severe enough for extinctions to occur. The resilience of an
ecosystem to climate change will be determined to a large extent by the degree
to which it already has been impaired by other human activities.
Coastal
ecosystems are especially vulnerable in this context. They are being subjected
to habitat degradation; excessive nutrient loading, resulting in harmful algal
blooms; fallout from aerosol contaminants; and emergent diseases. Human
interventions also have led to losses of living marine resources and reductions
in biodiversity from biomass removals at increasingly lower trophic levels. The
effects on biodiversity are likely to be much less severe in the open ocean
than in estuaries and wetlands, where species in shallow, restricted
impoundments would be affected long before deep-oceanic species.
The chief biotic
effects on individuals of an increase in mean water temperature would be
increased growth and development rates. If surface temperatures were correlated
positively with latitude, and temperature increased, one would expect a
poleward shift of oceanic biota. While this may be the general case, there
could be important regional variations due to shifts in atmospheric and oceanic
circulation. The resulting changes in predator-prey abundance and poleward
shifts in species’ ranges and migration patterns could, in the case of marine
fisheries, lead to increased survival of economically valuable species and
increased yield. Such cases have been observed as a result of the large and
intense 1983 El Niño.
In high
latitudes, higher mean water temperature could lead to an increase in the
duration of the growing period and ultimately in increased bioproductivity in
these regions. On the other hand, the probability of nutrient loss resulting
from reduced deep-water exchange could result in reduced productivity in the
long term—again highlighting the importance of changes in temperature on
patterns of circulation. Global warming could have especially strong impacts on
the regions of oceanic subpolar fronts, where the temperature increase in deep
water could lead to a substantial redistribution of pelagic and benthic
communities, including commercially important fish species.
Most migratory
organisms are expected to be able to tolerate changes, but the fate of
sedentary species will be dependent on local climate changes. Some corals would
be affected (as in the 1983 and 1987 bleaching events), but it is expected that
other stresses (e.g., pollution, sedimentation, or nutrient influx) may remain
more important factors. Intertidal plants and animals, such as mangroves and
barnacles, are adapted to withstand high temperature, and unless the 1.5°C
increase affects reproduction, it will have no effect. Similarly, only seagrass
beds already located in thermal-stress situations (i.e., in shallow lagoons or
near power plant effluents) are expected to be negatively affected by the
projected temperature rise. One cannot rule out, however, the possibility of
significantly greater tropical warming than 1.5°C. For example, some
investigators argue that tropical warming was approximately 5°C from the last
glacial maximum to today. If this value is correct, current GCMs probably
underestimate tropical sensitivity.
Changes in
temperature and salinity are expected to alter the survivorship of exotic
organisms introduced through ballast water in ships, especially those species
with pelagic larval forms. Introduction of exotic species is a form of
biological pollution because, from a human perspective, they can have adverse
impacts on ecosystems into which they are introduced and in some cases pose
hazards to public health. A classic recent example of the spread of an
introduced exotic species is that of the zebra mussel (Dressena polymorpha), which was transported to the Great Lakes via
transatlantic shipping from the Baltic sea.. Changes in temperature could
enhance the potential for the survival and proliferation of exotic species in
environments that are presently unfavorable.
Changes also can
be expected in the growth rates of biofouling organisms that settle on means of
transport, conduits for waste, maritime equipment, navigational aids, and
almost any other artificial structure in the aquatic environment. Their species
distributions often are limited by thermal and salinity boundaries, which are
expected to change with regional changes in temperature and precipitation.
Areas that experience warming and reduced precipitation (i.e., salinity
increases) likely will have increased problems with biofouling.
Predicted
climate change also may have important impacts on marine mammals such as
whales, dolphins, and seals, and seabirds such as cormorants, penguins, storm
petrels, and albatross. However, it is presently impossible to predict the
magnitude and significance of these impacts. The principal effects of climate
change on marine mammals and seabirds are expected from areal shifts in centers
of food production and changes in underlying primary productivity due to
changes in upwelling, loss of ice-edge effects, and ocean temperatures; changes
in critical habitats such as sea ice (due to climate warming) and nesting and
rearing beaches (due to sea-level rise); and increases in diseases and
production of oceanic biotoxins due to warming temperatures and shifts in
coastal currents.
Ice plays an
important role in the development and sustenance of temperate to polar
ecosystems because it creates conditions conducive to ice-edge primary
production, which provides the primary food source in polar ecosystems; it
supports the activity of organisms that ensure energy transfer from primary producers
(algae and phytoplankton) to higher trophic levels (fish, marine birds, and
mammals); and, as a consequence, it maintains and supports abundant biological
communities.
One of the
possible beneficial consequences of global warming might be a reduction in the
extent and stability of marine ice, which would directly affect the
productivity of polar ecosystems. For example, the absence of ice over the
continental shelf of the Arctic Ocean would produce a sharp rise in the
productivity of this region, provided that a sufficient supply of nutrients is
maintained. Changes in water temperature and wind regimes as a result of global
warming also could affect the distribution and characteristics of polynyas
(ice-free areas), which are vital to polar marine ecosystems. In addition,
changes in the extent and duration of ice, combined with changes in
characteristics of currents—for example, the circumpolar current in
southern latitudes—may affect the distribution, abundance, and harvesting
of krill. Krill are an important link in the ocean fauna in the Southern Ocean.
It is important to understand how, when, and where productivity in the Southern
Ocean will change with global warming.
A number of
marine organisms depend explicitly on ice cover. For example, the extent of the
polar bear’s habitat is determined by the maximum seasonal surface area of
marine ice in a given year. The disappearance of ice would threaten the very
survival of the polar bear, as well as certain marine seals. Similarly, a
reduction in ice cover would reduce food supplies for seals and walruses and
increase their vulnerability to natural predators and human hunters and
poachers. Other animals, such as the otter, could benefit by moving into new
territories with reduced ice. Some species of marine mammals will be able to
take advantage of increases in prey abundance and spatial/temporal shifts in
prey distribution toward or within their primary habitats, whereas some
populations of birds and seals will be adversely affected by climatic changes if
food sources decline or are displaced away from regions suitable for breeding
or rearing of young.
Animals that
migrate great distances, as do most of the great whales and seabirds, are
subject to possible disruptions in the distribution and timing of their food
sources during migration. For example, it remains unclear how the contraction
of ice cover would affect the migration routes of animals (such as whales) that
follow the ice front. At least some migrating species may respond rapidly to
new situations.
While the
impacts of these ecological changes are likely to be significant, they cannot
be reliably forecast or evaluated. Climate change may have both positive and
negative impacts, even on the same species. Positive effects such as extended
feeding areas and seasons in higher latitudes, more-productive high latitudes,
and lower winter mortality may be offset by negative factors that alter
established reproductive patterns, breeding habitat, disease vectors, migration
routes, and ecosystem relationships.
Convening
Lead Authors: J.T. Everett (USA) and B.
Blair Fitzharris (New Zealand)
Lead
Author: Barrie Maxwell (Canada)
Summary. Direct effects could include: ecosystem shifts,
sea and river ice loss, and permafrost thaw. Indirect effects could include
positive feedback to the climate system. There will be new challenges and
opportunities for shipping, the oil industry, fishing, mining and tourism,
infrastructure, and movement of populations, resulting in more interactions and
changes in trade and strategic balance. There will be winners and losers. As
examples, a reduced and thinning ice cover will disadvantage polar bears, while
sea otters will have new habitats; communities on new shipping routes will grow
while those built on permafrost will have difficulties. Native communities will
face profound changes impacting on traditional lifestyles.
·
Major physical, ecological, sociological, and economic
changes are expected in the Arctic, but much smaller changes are likely for the
Antarctic, over the period of this assessment.
·
Substantial loss of sea ice is expected in the Arctic
ocean. If there is more open water, there will be a feedback to the climate
system of northern countries by moderating temperature and increasing
precipitation. If warming occurs, there will be considerable thawing of
permafrost leading to changes in drainage, increased slumping and altered
landscapes over large areas.
·
Polar warming probably should increase biological
production, but may lead to different species composition. In the sea, marine
ecosystems will move poleward. Animals dependent on ice may be disadvantaged.
·
Human communities in the Arctic will be affected by
these physical and ecological changes. Effects will be particularly important for
indigenous peoples leading traditional lifestyles.
·
There will be economic benefits and costs. Benefits
include new opportunities for shipping across the Arctic Ocean, lower
operational costs for the oil and gas industry, lower heating costs, and easier
access for tourism. Increased costs can be expected from several sources
including disruptions caused by thawing of permafrost and reduced
transportation capabilities across frozen ground and water.
·
Sea ice changes in the Arctic have major strategic
implications for trade and defense.
Marine Ecological Systems. If warming should occur, there will be an increase
in growth and development rates of non-mammals. In general, productivity should
rise. Risks include the loss of sea ice cover upon which several marine mammals
depend for food and protection. Also, Arctic shipping, oil exploration and
transport, and economic development could bring risks to many
species.
·
Ice. If there is warming, the Arctic could experience a thinner
and reduced ice cover, including that in Arctic lakes and streams. In contrast,
the vast Antarctic is so cold that any warming within the IPCC scenarios should
have little impact except in the Dry Valleys and on the Antarctic Peninsula. In
fact, ice could accumulate through greater snowfall, slowing sea level rise.
·
Permafrost. Permafrost underlies as much as 25% of the global land
surface. Considerable amounts will disappear, causing major changes in
ecosystem structure and in human impacts.
·
Fisheries. Warming could lead to a rise in production, unless
changes in water properties would disrupt the spawning grounds of fish in high
latitudes. There could be a substantial redistribution of important fish
species. Fisheries on the margin of profitability could prosper or decline.
Fishing seasons will lengthen, but most stocks are already fully exploited.
·
Navigation and Transport. If sea-ice coverage is reduced, coastal and river
navigation will increase. Opportunities for water transport, tourism, and trade
will increase. The Arctic Ocean could become a major trade route. Seasonal
transport across once frozen land and rivers may become difficult or costly.
Offshore oil production should benefit from less ice.
·
Arctic Settlements. If the climate ameliorates, conditions will favor the
northward spreading of agriculture, forestry, and mining, with an expansion of
population and settlements. More infrastructure such as marine, road, rail, and
air links would be required. Changes in the distribution and abundance of sea
and land animals will impact on traditional lifestyles of native communities.
Co-Chairs: John. Everett USA; Alla Tsyban (Russia); Jim
Titus (USA)
Co-Chairs: John. Everett USA; Alla Tsyban (Russia); Martha
Perdomo (Venezuela))
These two
report’s findings were incorporated into subsequent reports and are included
above, with the possible exception that these made a stronger case for the
impacts of sea level rise. Since the projected amount of rise has now been
rolled back in the latest scientific assessment due to a lack of acceleration
in sea level rise, these findings are no longer relevant. Some of their
adaptation recommendations are included below.
Research Needs
Information is
most valuable if there are institutions and management mechanisms to use it.
Research on improved mechanisms is needed so that fisheries can operate more
efficiently with global warming as well as in the naturally varying climate of
today. There is relatively little research underway on such mechanisms.
Knowledge of the reproductive strategies of many species and links between
recruitment and environment is poor.
The following items are needed specifically because of
climate change. Other types of research, which are prerequisites for dealing
with such concerns but which support the day-to-day needs of fisheries managers
or relate more to understanding how ecosystems function, are not included.
·
Determine how fish adapt to natural extreme
environmental changes, how fishing affects their ability to survive unfavorable
conditions, and how reproduction strategies and environments are linked. Link
fishery ecology and regional climate models to enable broader projections of
climate-change impacts and improve fishery management strategies.
·
Implement regional and multinational systems to detect
and monitor climate change and its impacts—building on and integrating
existing research programs. Fish can be indicators of climate change and
ecological status and trends. Assemble baseline data now so comparisons can be
made later.
·
Develop ecological models to assess multiple impacts of
human activities.
·
Determine the fisheries most likely to be impacted, and
develop adaptation strategies.
·
Assess the potential leaching of toxic chemicals, viruses,
and bacteria due to sea-level rise and how they might affect both fish and the
seafood supply.
·
Determine institutional changes needed to deal with a
changing climate. Such changes are likely the same ones needed for mastering
overfishing and coping with the variability and uncertainty of present
conditions. Improved institutions would probably reduce stock variability more
than climate change would increase it.
·
Study the historical ability of societies to adapt
their activities when their resources are impacted by climate changes.
·
Research activities to better understand processes in
the oceans, in particular the role of the oceans in the natural variability of
the climate system at seasonal, interannual, and decadal to century timescales.
·
Long-term monitoring and mapping of: water-level
changes, ice coverage, and thermal expansion of the oceans; sea-surface
temperature and surface air temperature; extratropical storms and tropical
cyclones; changes in upwelling regimes along the coasts of California, Peru,
and West Africa; UV-B radiation, particularly in polar regions, and its impact
on aquatic ecosystems; regional effects on distribution of species and their
sensitivity to environmental factors; changes in ocean biogeochemical cycles.
·
Socioeconomic research activities to document human responses to global change
·
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)
·
Coastal planners and owners of coastal properties and
infrastructure should carefully consider projected relative sea level changes
when evaluating new or reconstruction projects.
·
Coastal planners and environmental decision-makers
should consider that a healthy environment is a prerequisite for coral reefs,
mangroves and sea grasses to keep pace with a rising sea and to continue their
coastal protection benefits
In
this light I view with grave concern the two latest IPCC Summary for Policy
Makers which use truncated data in text and graphics to misrepresent the amount
of warming, causing undue alarm. For example, from the most recent SPM, “The
Working Group I Fourth Assessment concluded that most of the observed increase
in the globally averaged temperature since the mid-20th century is very likely
due to the observed increase in anthropogenic greenhouse gas concentrations.
….” This is a red flag. It begs
the question of why the restriction “since the mid-20th century”. What is wrong
with the full data set back into the 1800s? Is it restricted to “mid-20th century”
because it is too difficult to explain the prior decades of falling
temperatures in the face of rising CO2? This demonstration (and there are many
others) is typical of what has led many disagreeing scientists to not be
invited to IPCC anymore, and others to lose interest. Over 20 years the core
IPCC-participating scientists have become more homogeneous. The consensus has
become stronger as dissenting scientists have moved to become the “other
consensus”, usually called climate skeptics.
The
source of the warming or cooling is of little importance to an impacts
assessment, except where it provides a clue as to future trends. Most people
agree that there has been a warming of 1 degree Fahrenheit in the instrumental
record of 150 years. Those in the “IPCC-oriented consensus” believe it is due
to mankind’s increased CO2 and other gas emissions; therefore temperatures are
likely to rise as more humans inhabit the earth and economies grow. This is
important information to a specialist in assessments. Also important, though,
is staying in touch with other views. Scientists in the “other consensus”
believe that, even if the 1 degree change is accurate (and is not just
“noise”), the CO2 rise can, at most, explain a piece of the temperature rise.
Many believe that increased water vapor, solar variations in radiation and
magnetic flux, our relative position in the solar system, the tilt of our
planet’s axis, the clearing of our atmosphere of pollutants which allows more
sunlight to reach the ground, or our position in the Milky Way galaxy that
affects the amount of radiation reaching our atmosphere and affecting cloud
formation, are also important and are not (and cannot be yet) adequately
considered in the computer models used by the IPCC consensus. Many believe CO2
may not be the culprit.
Personally, I do not know whether the earth is going
to continue to warm, or that having reached a peak in 1998, we are at the start
of a cooling cycle that will last several decades or more. Whichever it is, our
actions should be prudent. Our fishing industry, maritime industry and other
users of the ocean environment compete in a world market and are vulnerable in
many ways to possible governmental actions to reduce CO2 emissions. We already
import most of our seafood and many of the nations with which we compete do not
need further advantages. Our research should focus on those ecosystem linkages
we need to understand in order to wisely manage our fisheries, and this
includes the ability to incorporate natural climate variability along with long
term changes. Institutionally, we should work with our neighbors to
pre-determine what should happen when one of our major fish stocks ignores the
international boundary. Lastly, I would like to draw the Committee’s attention
to the testimony of Dr. Steven Murawski, of NMFS, at a hearing on Projected and Past Effects of Climate Change: a Focus on
Marine and Terrestrial Ecosystems before the Senate Committee on Commerce, Science
and Transportation, Subcommittee on Global Climate Change and Impacts, on April
26, 2006. I think it is well done, although I would quibble with some minor
points.
References:
1.
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
2.
Ittekkot, V., Su Jilan, E.
Miles, E. Desa, B.N. Desai, J.T. Everett, J.J. Magnuson, A. Tsyban, and S.
Zuta, 1995: Oceans. In: IPCC Second Assess. 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
Univ. Press, Cambridge and New York, 20 pp
3.
Everett, J.T. and B.B.
Fitzharris, 1998: Polar Regions: Arctic/Antarctica. In: The Intergovernmental Panel on Climate Change
(IPCC) Special Report on Regional Impacts of Climate Change [Watson, R.T., M.C.
Zinyowera, and R.H. Moss (eds.)]. Cambridge Univ. Press, Cambridge and New
York.
4.
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
5.
Everett, J.T., A. Tsyban and M.
Perdomo. 1992. Climate
Change: World Oceans and Coastal
Zones: Ecological Effects. In IPCC (Intergovernmental Panel on Climate
Change),. Climate Change, The Supplementary Report to the IPCC Impacts Assessment,
W.J.McG Tegart, G.W.Sheldon (Eds) Australian Government Publishing Service, 112
pp.
This page updated or reviewed in April 2010