Ocean Observer - Climate Change and Oceans

Changing Climate, Changing Oceans

Mark Spalding, The Ocean Foundation¹

 

Global climate and the world ocean are inexorably linked. This is not merely because the ocean's ecosystems, like all others on earth, are affected by climate changes, but also because it is the oceans that drive planetary climate and weather. Changing climate changes the marine environment, but so too does a changing marine environment contribute to global climate change.

Introduction: Oceans and Climate

The global ocean hums with life that exists in an interconnected web, from the tiniest shrimp to the great blue whales. Humans, though creatures of land, are immersed in this web too -- sustained by the ocean's bounty and inspired by its beauty. The ocean also provides us with a wide variety of goods and services including food, recreation, and transportation.

Our use of marine goods and services has been profligate-and we have only recently begun to recognize and try to address the impact of our collective actions on marine species and habitats. We are also only just beginning to learn the details of how global climate change will affect the ocean. But we know enough to recognize our growing influence on its future.

Despite ongoing political debates, the unavoidable reality of global climate change has been documented by leading scientists and affirmed by international consensus. We can expect the unexpected-real climate change will include changes in weather patterns, changes in ambient temperatures, changes in precipitation and rises in sea levels. Sea level rise will gradually inundate existing coastal lands and coastal wetlands may extend further inland.

A few degrees of warmth may not sound like much of a threat, or even necessarily a bad thing. But the overall effects on weather patterns, disease, food production and coastal cities could reach deeply into the economy and our daily lives, from Bangladesh to New York City. With the oceans, we already need to be planning for and investing in solutions to mitigate the impact of climate change-because the impact is being felt now, and more is coming. Over half of the world's population lives along the coast, increasing the threat of economic and social disruption from rising sea levels, storm systems that are more frequent and more intense, and the loss of productive coastal ecosystems.

 

Climate Trends and Projections for the Global Ocean

Oceans and Atmospheric Weather System

Climate change is expected to have an impact on a variety of different climate dependent services, including agriculture, water supply, ecosystem health, human health, and weather. Climate is of prime importance in the economic, social and environmental health of our cities, coastal states and oceans. The ocean drives our planet's climate systems. Temperature differences between the ocean (which both heats and cools more slowly) and land create winds, and winds move air masses and their weather systems with them. Most of the precipitation that falls comes from evaporated seawater. The water we use to drink, wash, and water is linked to the ocean.

This excerpt from the 1998 Year of the Oceans report on the impacts of climate change explains the physics governing the behavior of the atmosphere and the ocean, thus how the ocean influences weather and climate:

The Earth's weather and climate are the result of the redistribution of heat. The major source of heat to the surface of the Earth is the sun, principally through incoming visible radiation most of which is absorbed by the Earth's surface. This radiation is redistributed by the ocean and the atmosphere with the excess radiated back into space as longer wavelength, infrared radiation. Clouds and other gases², primarily water vapor and carbon dioxide, absorb the infrared radiation emitted by the Earth's surface and remit their own heat at much lower temperatures. This "traps" the Earth's radiation and makes the Earth much warmer than it would be otherwise.

Most of the incoming solar radiation is received in tropical regions while very little is received in polar regions especially during winter months. Over time, energy absorbed near the equator spreads to the colder regions of the globe, carried by winds in the atmosphere and by currents in the ocean. Compared to the atmosphere, the ocean is much denser and has a much greater ability to store heat. The ocean also moves much more slowly than the atmosphere. The ocean moderates seasonal and longer variations by storing and transporting, via ocean currents, large amounts of heat around the globe, eventually resulting in changing weather patterns.

In short, without the oceans to "bank" the heat from the sun and redistribute it globally, the Earth would be freezing by night, and unbearably hot during the day. The ability of the oceans to absorb and transfer heat thus moderates the global environment.

Understanding the Role of Warmer Oceans in the Alteration of the Global Climate Regime

As climate change continues to warm the global ocean, it will change patterns of currents and gyres (and thus heat redistribution) in such a way that there will be a fundamental change in the climate regime as we know it, and possibly a powerful loss of global climate stability³. The basic changes will be an acceleration of phenomena that are already occurring: sea-level rise, alterations of rainfall patterns and storm frequency or intensity, and increased siltation.

Long-term impacts of climate change in coastal areas, such as sea level rise or storm surges, could result in the increased erosion of shores and associated habitat, increased salinity of estuaries and freshwater aquifers, altered tidal ranges in rivers and bays, changes in sediment and nutrient transport, and increased coastal flooding. Such changes have considerable implications for coastal areas where much of the world's population and significant economic activity is concentrated.

The key to understanding the loss of global climate stability is to compare global change to local change. The warming of the planet appears to be following a pattern that is statistically consistent with the increasing accumulations of CO2 in the atmosphere. As a result, the warming of the ocean is becoming more measurable and predictable. However, all these heat transfers create local dynamics that are significantly less predictable. At the local and regional scale, due to heat disparities and too numerous points of interaction, the indirect changes in local weather patterns will not be uniform, nor necessarily gradual, nor consistent over time. Rather than taking centuries to change, local weather changes are happening before our eyes. Less snow here, more rain there. Longer periods of drought, later arrival of spring rains. Earlier hurricanes and shorter winters. There will be an accompanying loss of biodiversity as ocean temperatures increase, sea levels rise, and disturbances increase.

Consequences of System Destabilization Due to Climate Change

Affected Marine Ecosystems and Species

Global climate change, with its associated sea-level rise, increased air and water temperatures, and changes in precipitation patterns, is predicted to alter marine environments through a variety of direct and indirect impacts. Global climate change introduces new instabilities into systems that are already greatly disturbed and altered by over-exploitation. As a result, marine ecosystems are being simplified and becoming less stable and less productive in all climate zones⁴. Stressed ecosystems in turn are more vulnerable to disease, which in turn can push them closer towards collapse⁵.
The polar regions, too, will likely become warmer and wetter. In the Arctic, sea ice will continue to thin and retreat, to the extent that by 2050, sea-ice cover in the Arctic Ocean may be reduced to about 80 percent of the area it covered in the mid-twentieth century. Such sea-ice declines may well have negative repercussions for many species of marine wildlife, including seabirds and marine mammals: seal species, for example, that use the sea ice as a platform on which to rest, and polar bears that prowl the ice to prey on seals⁶. Similarly, in Antarctica, the ice sheet is melting far more rapidly than predicted⁷. Although only a small fraction of ice has melted recently, the Antarctic continent stores 90% of the world's ice, and the accelerated melting trend is cause for concern⁸.

There are a number of key threats to the integrity and survival of marine ecosystems as a result of climate change. Basic physical changes caused by global warming include more frequent storms, shifting ocean currents, melting polar ice, and rising sea levels. These physical changes threaten food supplies, species health, habitat, and reproduction. It remains unknown whether these impacts will be gradual or abrupt, but certain regions have already seen dramatic change. For example, rapid sea level rise is currently underway in the United States, China, and Argentina⁹, increasing flood risk in coastal areas. Temperature changes are also taking their toll: as water temperatures have risen, the base of the marine food chain in certain areas has crashed. And, one by one, the fish and birds farther up that food chain are crashing too¹⁰.

Temperature affects species in a number of ways: directly, by causing thermal stress, indirectly, by affecting food supply, and even more indirectly, by affecting the timing of seasonal events which in turn affect the ability of marine species to survive and reproduce. Temperature also affects species by upsetting ecological balances, such as occurs with coral bleaching and subsequent mortality. Warming of seawater also is predicted to impede the ability of shelled organisms to create calcium carbonate, which could doom coral reefs and impact entire marine food webs (see Ocean Observer on Ocean Acidification in the W2O archives).

Recent reports from the Mediterranean suggest that it is not only the extreme environments of the poles and tropics that are changing rapidly. Warming of the Mediterranean Sea has resulted in a spread of invasive, thermophilic species (those species adapted to warmer waters), an overall loss of diversity, and the spread of marine disease. Continued climate-related degradation adds to a sea already stressed by development and resource use, and threatens one of the world's great natural treasures.

Displacement of Human Populations due to Erosion, Permafrost Melts and Sea Level Rise

Changing climate, rising sea level, loss of ecosystem services, exposure to pathogens or toxic pollutants, lack of potable water, as well as the costs of mitigation strategies may force human populations to relocate. The two most famous examples are Vanuatu, which expects its entire island nation population to become sea-level rise refugees, and Shishmaref and Kivalina, two villages in northwest coastal Alaska, which are in the process of being dismantled and moved at a cost to U.S. taxpayers of more than $100 million - over $100,000 per resident - as the result of coastal erosion and melting permafrost. And there are 20 other Alaska villages that are candidates (with similar costs) for relocation because of severe erosion¹¹.

Kiribati, the Marshalls, and Tuvalu are likewise involved in diplomatic discussions to seek settlements for refugees once their islands are "subsumed by rising sea levels linked to fossil-fuel-driven climate change."¹²

Human activities and alterations have rendered coastal resources more vulnerable to climate change-induced processes, such as accelerated sea-level rise, alterations of rainfall patterns and storm frequency or intensity, and increased siltation. Climate change and a rise in sea level or changes in storms or storm surges could result in the increased erosion of shores and associated habitat, increased salinity of estuaries and freshwater aquifers, altered tidal ranges in rivers and bays, changes in sediment and nutrient transport, a change in the pattern of chemical and microbiological contamination in coastal areas, and increased coastal flooding¹³. Rapid sea level rise is already currently underway in some parts of the United States, China, and Argentina, increasing flood risk in coastal areas¹⁴.

Impacts on Human Health due to Climate Change Induced Ocean Alterations

Waterborne pathogens such as red tides, ciguatera, and cholera all could increase as a result of climate change, harming fish stocks and consumers alike¹⁵. However, direct impact on human health is difficult to anticipate. Where climate change enhances the spread of disease carried by fish, mosquitoes and other species, human health will obviously be adversely affected¹⁶. In addition, it is possible that where warmer water temperatures cause more marine species diseases, those species may become unsafe for human consumption-much as "red tides" and other algal outbreaks have already affected the food supply. Further disruption to the food supply and thus to human health could come from saltwater intrusion into coastal agriculture lands, destruction of agriculture and transportation infrastructure in storms and floods, and changes in precipitation patterns that reduce agricultural productivity.

Patterns of mortality in large urban populations, which may change as a result of hotter summers and less cold winters, could cause higher death rates in the very old and the very young (witness the deaths associated with the heat wave in France last year). If a region becomes dryer or the rainfall less regular, there may be more particulate matter in the air and thus there will be increased problems related to respiration. In addition, if the heat reduces ultraviolet radiation protection in the atmosphere, it can be expected we will see more skin cancer in some regions. We have already observed this with the case of ozone depletion in which some countries have had to adopt new health policies in respond.

Coastal flooding and the offshore formation of hurricanes and all the other ocean-related extreme weather events are sources of human mortality that may increase. And such events, in conjunction with other forms of food supply disruption, could increase forced migration and relocation-which often in turn generate conditions that increase the risk of disease¹⁷.

Geopolitical Instability

Recent research suggests that there is a possibility that gradual global warming could lead to a relatively abrupt slowing of the ocean's thermohaline conveyor, which could lead to harsher winter weather conditions, sharply reduced soil moisture, and more intense winds in certain regions that currently provide a significant fraction of the world's food production. With inadequate preparation, the result could be a significant drop in the human carrying capacity of the Earth's environment¹⁸.

There are some indications today that global warming has already reached the threshold where the thermohaline circulation could start to shift. The North Atlantic is substantially less salty as the result of "being freshened by melting glaciers, increased precipitation, and fresh water runoff . . . over the past 40 years."¹⁹ A U.S. Department of Defense report analyzes how such an abrupt climate change scenario could de-stabilize current geo-politics, leading to skirmishes, battles, and even war over resource constrictions such as: 1) Food shortages due to decreases in net global agricultural production; 2) Decreased availability and quality of fresh water in key regions due to shifted precipitation patterns, causing more frequent floods and droughts; and 3) disrupted access to energy supplies due to extensive sea ice and storminess.

The U.S. Department of Defense report predicts that as glacial ice melts, sea levels rise and as wintertime sea extent decreases, ocean waves increase in intensity, damaging coastal cities. Additionally millions of people are put at risk of flooding around the globe (roughly 4 times 2003 levels), and fisheries are disrupted as water temperature changes cause fish to migrate to new locations and habitats, increasing tensions over fishing rights²⁰.

The study done for the U.S. Department of Defense has, of course, been criticized. On the other hand, recent publications offer confirmation of the use of the theory behind the Pentagon scenario. What these and the Pentagon report indicate is that a significant cooling in some places could be part of climate change, that both global warming and cooling will disrupt the balance of natural systems and thus international relations, and that we must act to reverse the trends to avoid political instability.

Addressing Climate Change and Ocean Conservation

The ocean provides many benefits in terms of resources, climate moderation, and aesthetic beauty. Frankly we cannot survive without the ocean and its marine environmental services. The world ocean provides approximately 17 percent of protein for human consumption. It absorbs carbon dioxide, it dilutes pollution, and its edges, the estuaries and wetlands, filter pollution from water, provide nursery and feeding grounds for key food species, and assist with flood control. If we do not sustain the sea, it will not sustain us.

Through human-induced warming of the ocean, we have perturbed natural balances at a scale way beyond the pollution, siltation, predation, and other human insults. In fact, we may be unleashing a terrible set of oscillations that exceed natural background ones. The good news is that some damage may be reversible. We also have evidence that some parts of the ocean system may have greater resilience than we thought. However, the risks of upsetting the natural balances that sustain life on the planet are so great that we must address the following issues quickly and carefully.

Ocean Energy

The carbon-based sources of energy needed to support a consumer society, from electricity to transportation, have continuous negative effects on marine ecosystems that must be addressed. Airborne nitrogen deposition from power plants and other sources contributes to the degradation of such key estuaries as Chesapeake Bay, Mobile Bay, and Florida Bay, in the U.S., and other similar habitats worldwide, reducing their resilience to climate change and increasing marine species' vulnerability to disease.

Yet there is an inherent conflict between mainstream recommendations for addressing climate change and some mainstream aspects of ocean conservation. On one hand, if we fail to stop the progress of climate change, the ocean could be ruined regardless of efforts to reverse or minimize the damage we have already done. On the other hand, some of the clean energy recommendations may require placing structures on the sea floor, or in the water column, or in coastal habitat-solutions that the ocean conservation community normally view as environmental threats. However, it seems clear that we cannot slow climate change without clean energy.

We are entering an era where energy issues have a growing connection to marine conservation efforts. Proposals for new oil and gas rigs and pipelines as well as facilities for liquefied natural gas have appeared up and down our coasts. There are also increased risks and impacts from seismic surveys on the continental shelf, particularly for marine mammals. There also is an increasingly vocal interest in tapping the oceans for alternative energy sources such as wind, seabed methane hydrates and tidal/wave power (see Ocean Observer An Ocean of Energy- There for the Taking in the W2O archives).

There are numerous reasons to be concerned about the potential expansion of energy infrastructure in marine and coastal ecosystems. They include: disruption of the benthic
communities and other ecosystems on the ocean floor, disturbance of toxic muds along coastal waters that would release PCBs and other poisons now capped, disruption of migratory paths for large pelagic species (and interference with their ability to communicate); additional release of mercury into the oceans through oil drilling; mortality of marine mammals and seabirds, other animals; and possible permanent changes to near shore fisheries through alteration of key ecosystems.

At the same time, scientists tell us that climate change could be the single biggest threat to the oceans in the near future-making reducing the emission of greenhouse gases an apparent priority. Tapping the ocean's methane and alternative energy reserves could displace fuels that are far more dangerous from a climate change perspective and thus may be worth the immediate environmental risk. Wind farms cause local disruption to marine ecosystems and coastal communities, but may bring regional improvements in air quality and reductions in nitrogen deposition into watersheds, as they replace "dirtier" sources of electric power.

A deep skepticism of all energy development has affected views on an "energy policy for the ocean". The track record of oil production and transport reinforces this skepticism. However, the complex intersection with the climate change issue and the promise of cleaner fuels argue for a careful, thoughtful reassessment of the "no way, no how" attitude towards coastal energy development. This is particularly true since having a positive environmental agenda with regards to energy may help leverage progress on marine protected areas, ecosystem-based planning and vital reforms to ocean governance.

Carbon Sequestration at Sea

Because carbon dioxide (CO2) is one of the major greenhouse gases causing the gradual warming of the Earth's surface and potentially disastrous changes to global climate, CO2 ocean sequestration is being explored as one possible approach to limit the accumulation of greenhouse gases in the atmosphere. CO2 released in very cold deep-water forms ice-like solids known as hydrates. There are a number of experiments ongoing to inject carbon dioxide into the deep ocean, and to then gather data in the vicinity of the CO2 injection point to improve our understanding of the basic physical phenomena, and to apply this data to refine the accuracy of predictive computer models that are needed to evaluate environmental impacts. Model validation is a first and necessary step to assess the physical, chemical and environmental effects of CO2 sequestration in the deep ocean.

CO2 ocean sequestration is a concept that was conceived in the early 1980s to avoid the rapid build-up of carbon dioxide in the atmosphere. However, there is rather daunting amount of scientific uncertainty surrounding impacts on the marine environment. Full-scale sequestration requires a lot more research before this concept sees the light of day. Using relatively shallow oceans (at roughly 800 meters) as a massive sink for removing immense amounts of CO2 pollution from global industry is merely transferring contaminants from land to sea. And anything stored that deep will be very difficult to recover and may well leak. Moving the problem of CO2 pollution encourages the continued use of fossil fuel for power generation. It would be much better to address climate change through clean energy solutions like hydrogen fuel cells, avoiding CO2 production in the first place.

In addition to increasing hydrates, the injection of CO2 results in lower pH (more acidic) waters. Creatures living on the sea floor (benthic communities) near the injection point could be affected by the acidic water; more mobile (swimming) animals are not expected to be harmed. An increase in atmospheric CO2 transfer into shallow waters has also been identified as an inhibitor in coral calcification, the building material for coral reefs.

Mitigation: Slowing the Rate of Climate Change

There is still some hope that we have the capacity to avoid accelerating climate change or at least, to slow the rate of change and improve our odds of addressing its impact. However, this issue lies at the intersection of social/political and biological/physical systems. An overwhelming majority of scientists think that continued growth of greenhouse gas emissions will certainly raise average global temperatures and change regional climates; the only questions are how much and how fast this will occur under various scenarios. The uncertainties associated with each modeling scenario have become an obstacle to adoption of a regulatory structure and related policies to reduce greenhouse gas emissions, even though the scientists have clearly called for human action to reduce greenhouse gas pollution as an imperative. While there is a lack of absolutes in scientific advice, the scientists have achieved a widespread consensus on the overall expected effect.

We are operating with a lack of political will to reverse perverse subsidies, together with unsustainable assumptions and trends built into our economic structure, such as ever-expanding consumption. There are in fact several good processes currently underway to deal with perverse fisheries subsidies, including at UNEP, FAO and WTO. However, these efforts tend toward the lowest common denominator; they will also have to run a gauntlet of domestic implementation legislation before they become a reality. There is an almost complete lack of long-range planning, certainly a significant lack of ecosystem planning, and very little precaution built into our human development model.

The precautionary approach and ecosystem management are the two pillars of sustainable management of marine resources, as embodied in international law that must be followed. Among other consequences, we may risk political instability through failure to address climate change induced degradation of our ecosystem supports for human health and economic well-being.

Mitigation technologies have been proposed that include: nuclear power, fuel switching (using fuels with lower carbon content, such as replacing oil or coal with natural gas), reforestation, renewable energies, energy conservation and improved energy efficiency. In addition, to address shocks to our system such as human health impacts, we will need to focus on the maintenance and improvement of our public health care systems and their responsiveness to changing climate conditions and to identifying vulnerable populations.

Adaptation

Our policymakers need to find the right incentive structures to get everyone to move in the right direction. There are two choices: change our lives through the exercise of restraint, or change in response to environmental catastrophe. Human capacity to exercise restraint is a source of hope, whether the restraint comes from new knowledge or gut-level compassion. Most of us do not live anywhere near the poverty level, we have room to reduce our consumption without undercutting our quality of life - "all but the poorest of us could choose to lead materially simpler lives, and thereby do less harm and reap more joy." But this is a hard sell to the general public unless such "joy" is truly and clearly attainable-and feels as much like independent choice as current lifestyles.

The fundamental climate change adaptation message is about coping with constant change in comparison to what we have come to expect. The past 10,000 years, during which modern civilization arose, has been a period of climate stability relative to what we know of earth's history. However, that stability, and the predictability for food production, travel, and where and how we build things, may be put into question when we ask what the oscillations from our perturbation of the climate system will look like.

More coastal areas will need to build structures to withstand stronger storms. We will have to retreat from the beach, giving the ocean the room it needs to expand. In 1998, NOAA summarized the coastal responses as follows:

(1) Accommodate. Vulnerable areas continue to be occupied, accepting the greater degree of effects, e.g., flooding, saltwater intrusion, and erosion; advanced coastal management used to avoid the worst impacts; improved early warning of catastrophic events; and building codes modified to strengthen structures.

(2) Protect. Vulnerable areas, particularly population centers, high-value economic activities, and critical natural resources, are defended by sea walls, bulkheads, saltwater intrusion barriers; other infrastructure investments are made; and "soft" structural options such as periodic beach re-nourishment, landfill, dune maintenance or restoration, and wetlands creation are carried out.

(3) Retreat. Existing structures and infrastructure in vulnerable areas are abandoned, inhabitants are resettled, government subsidies are withdrawn, and new development is required to be set back specific distances from the shore, as appropriate.

In its latest edition, of Basins and Coasts, USAID's newsletter on integrated management of coastal and freshwater systems, editor James Tobey has assembled a series of articles on climate change vulnerability and adaptation for coastal residents around the world²¹. The mainstreaming of climate and the oceans has begun.

Conclusions

The world ocean, which covers roughly 71 percent of Earth's surface, has the thermal inertia and heat capacity to help maintain and ameliorate climate variability. However, greenhouse gas emissions from human activities are projected to cause global climate change in excess of normal patterns, which in turn will alter coastal and marine ecosystems that are already stressed from human development, environmental pollution, and over-fishing. We need to act now if we hope to avert far worse perturbations of the natural climate system.

Unfortunately, fundamental societal change is required-the political will to adopt cleaner fuels (gasohol, alcohol), increase the use of wind and solar energy, and increase the efficiency of the technologies that do use fossil fuels. All of these solutions are at hand, available, and even economical-especially when all costs are considered.

The complex web of currents, temperatures, salinity levels, and chemistry that fosters life in the ocean is at risk of being irreversibly ruptured by the unpredictable, unstable, and overwhelming consequences of climate change. We have the opportunity to ensure that the oceans continue to provide us with critical food and other services, even as we work to limit the damage caused by our own excess. Each new report on the anticipated and projected effects of this new era of climate unpredictability seems to underscore the futility of conservation efforts-on land and at sea. In the long term, philanthropy's clear goal is to help bridge the gap between marine conservation and energy policy. However, focusing on resilience, on improving our knowledge of the oceans, and on fostering the ethic of moving quickly to limit human insult to our marine neighbors gives us more than a place to start-it gives us a strategy to improve sustainability in the short-term and in the long run.

 

Editor's note

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Climate change creates huge challenges for mankind. But focusing on climate change at the expense of ignoring other environmental issues also has its risks. When it comes to the world ocean, humans are stressing the system in myriad ways, and many of these stressors can be more easily mitigated than climate change. At the same time, there is every reason to believe that marine ecosystems that are intact and healthy are more resilient in the face of the inevitably changing climate. So while climate change is a wake-up call, recognition of the issue has even greater value in focusing our attention on a whole range of management and conservation measures that are needed to keep the world ocean alive and providing its many crucial services (including climate regulation).

 

Endnotes

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¹ This Ocean Observer is based on a paper commissioned by The Consultative Group on Biodiversity, written by Mark Spalding, and edited by Tundi Agardy of the World Ocean Observatory.

² The primary gasses which contribute to the greenhouse effect are: water vapor (H20), carbon dioxide (CO2), ozone (O3), methane (CH4), nitrous oxide (N2O), and chlorofluorocarbons (CFCs). Developed countries produce roughly 70 percent of the CO2 emissions (mostly from burning fossil fuels). The United States, with only 5 percent of the world's population, accounts for 22-26 percent of global CO2 emissions from human activities, and 20 percent of methane.

³ Wolfson, R. and S. H. Schneider. 2002. "Understanding Climate Science." In Climate Change Policy. Island Press, Washington D.C., pp. 3-51.

⁴ Worm, B., H. K. Lotze, H. Hillebrand and U. Sommer. 2002.Consumer versus resource control of species diversity and ecosystem functioning. Nature 417

⁵ Harvell, C.D., C.E. Mitchell, J.R. Ward, S. Altizer, A.P. Dobson, R.S. Ostfeld and M.D. Samuel. 2002. "Climate warming and disease risks for terrestrial and marine biota." Science 296: 2158-2162. See also, Parson, E.A., L. Carter, P. Anderson, B. Wang and G. Weller. "Potential consequences of climate variability and change for Alaska." U.S. National assessment of potential consequences of climate variability and change, Chapter 10. U.S. Global Change Research Program.

⁶ Motavalli, Jim (ed.) 2004. Feeling the Heat: Dispatches from the Frontlines of Climate Change Routledge Publishers page 108.

⁷ See Marc Kaufman's Washington Post article entitled "Escalating Ice Loss Found in Antarctica - Sheets Melting in an Area Thought to be Unaffected by Global Warming. Page 1, January 14, 2008

⁸ See article by Nicole Itano entitled "The Storied Mediterranean Faces Climate Change", Christian Science Monitor Jan 14, 2008 edition

⁹ Intergovernmental Panel on Climate Change. 2001. Third Assessment Report.

¹⁰ Motavalli, Jim (ed.) Feeling the Heat page 119.

¹¹ Rosen, Yereth "Warming climate disrupts Alaska Natives' lives" Reuters April 16, 2004.

¹² Motavalli, Jim (ed.) Feeling the Heat page 137

¹³ NOAA 1998 Year of the Ocean "Impacts Of Global Climate Change" Washington, DC
available at: http://www.yoto98.noaa.gov/yoto/meeting/climate_316.html

¹⁴ Intergovernmental Panel on Climate Change. 2001. Third Assessment Report.

¹⁵ Stevens, William K. "Linking Health Effects to Changes in Climate" New York Times, August 10, 1998.

¹⁶ See Shope, R. E. 1992. Impacts of global climate change on human health: Spread of infectious disease. Chapter 25 of Global climate change: Implications, challenges and mitigation measures, ed. S. K. Majumdar, L. S. Kalkstein, B. Yarnal, E. W. Miller, and L. M. Rosenfeld, 363-70. Easton, PA: The Pennsylvania Academy of Science. Available at http://www.ciesin.org/docs/001-367/001-367.html

¹⁷ For more information on health impacts, see the 2000 US Global Change Research Program's "National Assessment of Climate Change" health issues analysis available at:
http://www.usgcrp.gov/usgcrp/Library/nationalassessment/overviewhealth.htm

¹⁸ Schwartz, P. and D. Randall. 2003. An Abrupt Climate Change Scenario and Its Implications for United States National Security, Prepared for the Office of the Secretary of Defense, Washington DC, page 1

¹⁹ Schwartz, P. and D. Randall. 2003. An Abrupt Climate Change Scenario and Its Implications for United States National Security, Prepared for the Office of the Secretary of Defense, Washington DC, page 3

²⁰ Schwartz, P. and D. Randall. 2003. An Abrupt Climate Change Scenario and Its Implications for United States National Security, Prepared for the Office of the Secretary of Defense, Washington DC, page 9

²¹ Available at http://www.imcafs.org