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Presidential Climate Action Project: Situation Analysis for Oceans and Global Warming Draft 5, May 24, 2007, Jane Elder w/ additions from Jim Baker, Bill Becker and Mark Spalding
Oceans and Global Warming
The world’s oceans are the “engines” of Earth’s life support systems. They moderate the climate and support ecological and physical processes that store carbon and the heat from sunlight. Ocean plants produce more oxygen than all of Earth’s forests combined,1 and from productive coral reefs to their great depths, the oceans support diverse marine life that feeds 3.5 billion people.2
Oceans also play a major role in international commerce and shipping, recreation, tourism, and national security. While oceans sustain the vast majority of life on Earth, their resilience and productivity have already been damaged by overfishing, bycatch, pollution, and coastal development and now increased acidity from growing concentrations of carbon dioxide in the atmosphere.3
Rising global temperatures and higher carbon dioxide levels are changing the oceans in three significant ways: sea level is rising, ocean temperatures are warming, and seawater is becoming less saline and more acidic. In combination with other environmental stresses, these additive impacts from global warming are producing a cascade of negative changes in the physical, chemical and biological composition of the world’s oceans. These are increasing the likelihood of weather-related disasters, diminishing the ocean’s ecological vitality, and threatening human food supplies and settlement patterns. As a result, an informed and strategic ocean policy is critical for human health, well-being and stability.
The U.S. Exclusive Economic Zone – 200 miles out from our coasts – is larger than the continental U.S., but we haven’t done a good job of managing this marvelous ocean resource, which is threatened by global warming. Federal jurisdictions are spread among several agencies and often overlap. State, regional, and local governance is poorly coordinated. Two independent commissions on U.S. ocean policy – the Pew Oceans Commission in 2003 and the U.S. Commission on Ocean Policy in 2004 – have reached the conclusion that we need a major governance overhaul.4
All Americans are affected by the ocean, including coastal waters, estuaries, and the Great Lakes -- and we all affect it. Our prosperity and our security require bold leadership and active intervention to protect, restore and monitor the on-going changes in the ocean’s beleaguered life support systems – especially in the face of growing threats from global warming.
In addition, as the nation that currently contributes the most CO2 to the atmosphere, we have a parallel responsibility to play the leading role in responding to global warming’s impact on the world’s oceans. The 44th President has the opportunity to chart a new era of ocean policy for the United States and step up to an unprecedented and much needed leadership role in global ocean conservation and stewardship. The new President should take a step beyond the recent ocean commissions and establish an independent oceans agency that can take the actions necessary to deal with these critical issues.
► Sea Level Rise
Sea level is rising because water expands when it warms and because more fresh water is entering the oceans from melting terrestrial ice sheets and glaciers. Sea level has already risen from four to eight inches in the last century, and is expected to rise between seven inches and two feet by the end of the 21st Century. If melting of Greenland and Antarctica continue at the present rates, the upper range for sea level rise could reach almost three feet. Accurate and continuing long-term measurements of sea level from tide gauges and satellite-borne instruments are a critical aspect of monitoring these changes.5
The effects of sea level rise can be magnified more than one hundredfold along sloping beaches and deltas, especially with major storms. As a consequence, more than 600-million people (1 out of 10 on Earth) live in river deltas, islands and low-lying coastal areas that face probable inundation.6 Nations with particularly large population densities in low elevation coastal areas include China, India, the USA, Indonesia, Vietnam, Japan, Bangladesh, and of course, the many island nations7. Rising sea level will displace mass human populations, increasing economic and political destabilization in many areas where stability is already tenuous. In the U.S., we can expect substantial inundations in southern Florida, and in low-lying coastal communities and major cities throughout the Gulf and Atlantic coasts.8 Inundation will also force relocation (or loss) of coastal infrastructure,9 such as seaports, sewage treatment facilities, military installations, yacht clubs, marinas, airports, etc.
Rising seas will affect marine life and coastal habitat. Shallow water coral reefs depend on sunlight and sea level rise will reduce light penetration, threatening critical fish habitat. Along the coasts, important coastal wetlands, low-lying beaches, and estuarine habitat—“nurseries” for marine wildlife and waterfowl—will be “drowned” with limited opportunities for alternative habitats to emerge on highly developed or “hardened” areas along coasts.10 This will decrease biodiversity, disrupt food webs, and coastal regions will lose natural sediment traps and flood protection provided by existing natural habitats.
In addition, drinking water sources in coastal regions are at risk from saltwater intrusion. Salt-water intrusion into underground water resources is already a problem in many coastal states (e.g., CA, MA, NC, SC and FL)11 as well as in low-lying coastal areas elsewhere in the world. Continued intrusions will exacerbate shortages of clean, fresh water for human populations, and increase energy costs for strategies such as desalinization.
► Loss of sea ice
Warmer ocean temperatures are reducing sea ice cover.12 We are already experiencing a dramatic loss of sea ice in the Polar Regions and scientists project at least a 40-50% loss of Arctic sea ice by 2090. (A Canadian model projects an ice-free Arctic summer by 2095.)13
Shrinking sea ice will mean catastrophic losses in habitat for species such as polar bears, seals, penguins, and krill14 and species that feed on krill, such as many species of whales. An ice-free Arctic Ocean takes Earth into a climatic regime never experienced by humans on Earth; the best evidence is that that last time the Arctic was ice-free was 55 million years ago.
Loss of sea ice and rising sea levels is also causing severe coastal erosion in Alaska. Already, the ancient Alaskan villages of Shishmaref and Kivalina are being forced to relocate inland due to severe erosion caused by lack of protective sea ice.15 Estimated taxpayer costs are $180 million for Shishmaref alone,16 and another 20 villages are at risk.
An increasingly “open” Arctic will throw international shipping and the associated coastal communities into turmoil, as new routes open and old routes and ports become unprofitable. Moreover, any new economic opportunities pale in comparison to the losses to traditional cultures, costs of relocating coastal communities, and the anticipated losses and potential extinctions of species that depend on sea-ice habitat.
► Coral bleaching and ocean pathogens are increasing
Warmer water is exacerbating coral bleaching at a faster rate than ever before,17 and fostering conditions that increase levels of toxic algae, viruses and disease, especially in tropical waters.18 Both factors are increasing the loss of already threatened coral reefs through the world.
Warming seawater also threatens the marine foodweb. Warm, low-nutrient surface waters support less phytoplankton (microscopic plant life) than cold, deeper nutrient-rich waters, and phytoplankton are the base of the base of the ocean foodweb. Today, we are witnessing the “blue ocean effect” in which the ocean appears “bluer” because there is less plant life than in previous decades that produced familiar “sea-green” water. 19 Less plant life not only means less food for ocean life, but also less carbon dioxide absorption and oxygen production.
►Warm ocean water fuels hurricanes and storms
Warm surface waters fuel hurricanes; for example, Hurricane Katrina intensified strongly as it moved over a warmer-than-normal Gulf of Mexico. Global warming models project increased frequency and intensity of storms, hurricanes and storm surges. While a single storm cannot be attributed to climate change, the trend points to stronger hurricanes. According to the National Oceanic and Atmospheric Administration: “The strongest hurricanes in the present climate may be upstaged by even more intense hurricanes over the next century as the earth's climate is warmed by increasing levels of greenhouse gases in the atmosphere. Although we cannot say at present whether more or fewer hurricanes will occur in the future with global warming, the hurricanes that do occur near the end of the 21st century are expected to be stronger and have significantly more intense rainfall than under present day climate conditions…based on an anticipated enhancement of energy available to the storms due to higher tropical sea surface temperatures.” 20
Moreover, warmer sea surface temperatures can lead to droughts, not just in coastal regions but thousands of miles away in the interior of continents as well. It is essential that we continue to monitor globally the changing temperatures of the ocean and that we understand how the ocean links with the atmosphere to produce hurricanes, droughts, and other extreme weather.
►Fresher, more acidic seawater is changing the chemistry of ocean life
Over the course of history, life on Earth has become finely tuned to the natural chemistry of the ocean. As President Kennedy once observed, the blood coursing through our veins has the same salinity as seawater. But, now, the chemistry of seawater is rapidly changing and so is the web of life that depends on it. The massive infusion of fresh water from melting continental and glacial ice is reducing the saltiness of the oceans. In addition, as the ocean absorbs more CO2, from increased concentrations in the atmosphere, seawater is becoming more acidic, because in water, CO2 is stored as carbonic acid. Thomas E. Lovejoy, president of the H. John Heinz III Center for Science, Economics and the Environment describes ocean acidification as “the single most profound environmental change I've learned about in my entire career."21
Increased acidity decreases the available calcium carbonate in ocean water that shellfish use to form shells, and from which corals form and create reefs. As a result, projections point to a grim future for shellfish and corals and potential of extinctions throughout the world, because scientists expect ocean acidity to increase further over the next century.22 However, as seawater warms, it has less capacity to absorb CO2. Ironically, as ocean temperatures increase, there may be some reduction in the acidification trend by decreasing seawater’s ability to store carbon. 23 In any case, the rapid change of carbon dioxide concentration is limiting the ability of the ocean to respond. We need to monitor the changing chemistry of the ocean and to understand precisely how that changing chemistry affects living resources.
► Potential slowing of the ocean conveyor belt
Ocean currents are part of a “global ocean conveyor belt” of moving water that circulates warm and cold ocean water, distributes nutrients that fuel the ocean foodweb, and moderates weather. In the Atlantic Ocean, the currents transfer heat to the atmosphere, resulting in a milder climate for Europe than would otherwise be the case. In the Pacific Ocean, water temperatures shape currents and air masses that determine whether or not we will experience an “El Niño” year (which alters the distribution of ocean food supplies, and tends to produce coastal storms and warm winters in North America and droughts in the tropical Pacific).
The rapid infusion of fresh water is not only altering ocean chemistry, it is changing the dynamics of ocean currents, because fresh water is more buoyant than saltwater. An analysis by the Woods Hole Oceanographic institute cautions: “Continued freshening of the North Atlantic could slow the ocean conveyor, diminishing the amount of heat transported northward and significantly cooling areas of the Northern Hemisphere.”24 So, within the context of overall global warming, some regions, such as Northern Europe, could face a shift to a colder, more extreme, and less hospitable climate, with considerable social and economic consequences.
Changes in the speed and patterns of ocean currents will also affect their capacity to bring nutrient-rich cool waters to the surface, and thus may disrupt and diminish food sources for the global fishery. El Niño years provide a vivid example of how changes in temperature and currents affect fisheries. During the 1997-1998 El Niño Southern Oscillations (ENSO) period there was a dramatic decrease in squid catch from “a high of nearly 90,000 metric tons in 1996 to almost zero landings in 1997.”25
A 2002 interview with Harvard Oceanographer, James McCarthy, points out, “Nobody knows how climate change will affect currents, stratification, and nutrient supply. ‘But to say that the ocean will continue working just the way it is, and that the biological pump will continue to work the way it does at present—this is sophistry,’ says McCarthy. ‘We know that it will not.”26 In order to be ready to adapt to these changes, we need to monitor the ocean carefully and we need robust research programs to understand these complex links.
► “Engineered” Carbon Sequestration in the Oceans
The oceans are also one of Earth’s largest natural “sinks” or storage sites for carbon. The oceans currently absorb close to half of the CO2 from fossil fuel emissions in the atmosphere.27 However, as noted, the ocean’s natural carbon storage capacity is decreasing as waters warm, as phytoplankton decrease, and seawater becomes more acidic.
Some have proposed that the oceans can be used for additional carbon storage, but the complex balance between ocean biology and chemistry raises many questions about the efficacy and potential environmental downsides of these approaches.
The Department of Energy identifies two strategies for ocean-based carbon sequestration: “1) the enhancement of the net oceanic uptake from the atmosphere by fertilization of phytoplankton with micro- or macronutrients, and 2) the direct injection of a relatively pure CO2 stream to ocean depths greater than 1000 meters.”28 The DOE, points out, however, “The long term effectiveness and potential environmental consequences of ocean sequestration by either sequestration strategy are unknown.29 For example, the same nutrients that stimulate phytoplankton might also stimulate toxic algae blooms.30 And, as noted, increasing carbon dioxide levels in the ocean will also increase seawater acidification and its impact on shellfish, corals and food supplies. The unknowns here mean that we must proceed carefully – we don’t want to create a bigger problem than the one we wanted to mitigate. Careful monitoring and research are required on oceanic biodiversity and habitats before such sequestration can be considered a sensible solution.
Additional stresses from the impacts of global warming will exacerbate existing threats to ocean health and vitality. As noted, these include over-fishing, excessive bycatch and other damaging fishing practices, coastal development, sedimentation of coral reefs and near-shore habitats, and marine pollution. The net effect is diminished food supplies, increased threats to human health and safety, economic disruption. Particularly sensitive ecosystems include coral reefs, coastal wetlands (including mangroves), beaches, bluffs, barrier islands, Arctic and Antarctic sea ice and ice shelves, tidal pools, and river deltas.31 Particularly sensitive species include whales and other marine mammals, sea turtles, penguins (and other seabirds), polar bears, salmon (and other fish), corals, and shellfish.32
Changes in currents, ocean temperatures, seawater chemistry and loss of coral reef habitat threaten the vitality of the entire ocean foodweb, upon which all marine species depend. As such, global warming will contribute to declines in an already beleaguered global fishery, and as noted, likely population crashes or extinctions within shellfish and coral species. Overfishing has already led to a dramatic change in the abundance and size of marine animals – fewer large ones, and many more small ones. These changes, together with the impacts of global warming, will have commensurate impacts on fishing-dependent cultures–many of which will also lose communities and even homelands from rising seas. Global warming’s impact on the oceans will cut across the world’s economies and global food supply as well as human culture, society and well-being.
Strategies for Responsive Action
Strategies to respond to the impact of global warming on the oceans start with the obvious overarching need to reduce carbon dioxide emissions through a new “low carbon” energy strategy (see specific recommendations under the section on energy). This first step of mitigation of carbon dioxide emissions underlies all other actions.
Additional strategies to protect the marine ecosystem and human communities include emphasizing options that will:
Options for Action
1: Redesign Ocean Governance for the 21st Century: Create a Single U.S. Oceans Agency
Effective ocean policy requires effective governing structures, sufficient resources for agencies to carry out their mandates, access to expert advice, and accountability systems that provide straightforward measures of progress. It also requires focus, which can be achieved with a single agency (good examples include environmental protection with EPA and space programs with NASA).
Strengthening and overhauling the U.S. governance structure for ocean management with a central focused agency will provide the essential new framework for broader ocean conservation strategies that will help manage and potentially mitigate the impacts from global warming, both domestically, and internationally.
2: Put policies in place for adaptation to sea level rise and extreme weather: anticipate needs to relocate human communities and infrastructure as sea level rises and extreme weather events become more common; discourage development in vulnerable areas; revamp the federal flood insurance program
The U.S. Federal government can reduce the human and financial costs of sea level rise and extreme weather through anticipation, planning and preparedness. Near-term priorities include the need to anticipate increasing costs and social needs related to relocating human communities in Alaska, as well as long-term losses in traditional economies and the social fabric in villages that have depended on ocean-based hunting and fishing. In addition, coastal infrastructure in low lying areas throughout the United States needs to be assessed to identify areas of probable inundations, along with timelines and plans for specific needs for relocating infrastructure or developing “loss” strategies.
The Katrina hurricane experience tells us we need to assess and develop plans for regions that are at high risk from storm damage, and interruptions or loss of human services and infrastructure. These include transportation systems, telephone and electrical service, access to drinking water, and availability of emergency services. Evacuation strategies, building standards, and emergency response capacity need to be reconceived through the lens of increased probability of extreme weather. The Federal flood insurance program needs complete revamping, and this should be done together with states and the private sector to ensure both proper coverage and to discourage reckless building in dangerous areas.34
We also must anticipate and develop plans to address human dislocation and commensurate political, social and economic instability in a global context, from the standpoints of both humanitarian need and security.
3: Enhance and maintain a strong scientific base with a comprehensive ocean warning and monitoring system
Maintaining the many economic benefits we receive from the ocean in the face of global warming requires a strong scientific base including support of a long-term systematic observing system, making that data available, and carrying out related research so that we can understand and deal with these changes in a sensible way. Although we monitor the atmosphere well for weather changes and storms, we do not monitor the ocean well. Yet the ocean provides transportation, fishing, coastal development, recreation and tourism, receives and absorbs our wastes, and is a critical aspect of climate and weather forecasts.
We have difficulty separating out the natural fluctuations of the ocean from the effects of climate change and global warming. Relative to the atmosphere, we spend a pitifully small amount on ocean research and monitoring relative to the benefits we receive. For each of these areas, we need more continuing long-term support for a science base and a comprehensive coastal and global ocean observing system. Only in that way can we deal properly with sea level change, warming and acidification, and ecosystem and habitat change.
4: Maximize resilience and health by reducing other stresses
By controlling and eliminating other sources of environmental stress on ocean ecosystems we can create the “maximum window of resilience” for natural systems and species to withstand and even buffer the negative effects of global warming Opportunities lie in controlling and eliminating pollution to the marine environment; aggressively protecting species from overfishing and bycatch; and strictly limiting coastal development and thus protecting critical marine habitat—especially coral reefs, mangrove forests and coastal wetlands.
In addition, we need to anticipate sea level rise and plan for shifts and transitions in wetland and coastal ecosystems, as well as changes to barrier islands, beaches and reefs that provide storm protection. More vigilant and forward-thinking conservation approaches will also require careful allocation of restoration and protection resources.
5: Maximize opportunities to stave off extinctions. Plan for loss of ecosystems, habitats and populations
Traditional approaches to protecting endangered species will need to be re-“imagined” to address the loss of entire habitats and ecosystems, such as the polar ice cap, and highly vulnerable systems such as coral reefs, mangroves and seagrass beds. Aggressive short-term actions to maximize habitat and reduce stress for species at risk in threatened ecosystems will help preserve options for longer-term strategies.
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Key U.S. Federal Policies that affect Ocean Health
1. For sea level rise: Florida “inundation” graphic. See Rosina Bierbaum’s Power Point from December 06 Wingspread meeting
2. For global conveyor belt: excellent graphic on 2007 IPCC Web site, and also good graphics in Ruth Curry’s power point on Woods Hole Web site.
3. Nice graphic of projected sea ice change in paper on Alaska. http://www.usgcrp.gov/usgcrp/Library/nationalassessment/overviewalaska.htm
4. Greenland Graphic John Holdren’s Power Point (and many other sources)
5. Several good “text boxes/side bars” on various topics, if we need enrichment, including…
a. Potential Impacts of Climate Change and Sea-Level Rise on Coastal Systems from IPCC 2001 report
b. Summary of threats from CGBD paper
6. Images of marine biodiversity from the Census of Marine Life (some really wonderful pictures here)
7. Images of the satellites that carry ocean-measuring instruments
8. Images of the tracks of animals carrying instruments for monitoring the ocean
8. Acid Ocean Image
9. El Nino ocean temperatures and impacts on US
1 Science@NASA, The Oceans and the Carbon Cycle. http://science.hq.nasa.gov/oceans/system/carbon.html
2 Ocean and Human Health White Paper, Center for Health and Global Environment, Harvard Medical School, June 2006. http://chge.med.harvard.edu/education/public/healthyoceans/ocean_whitepaper.pdf
3 Climate Change and Oceans: Consultative Group on Biological Diversity. Mark J. Spalding
4 These two reports are An Ocean Blueprint for the 21st Century U.S. Commission on Ocean Policy, Executive Summary http://www.climateactionproject.com/docs/Exec_Summary_USCOP_Report.pdf (or www.oceancommission.gov/documents/prelimreport/welcome.html_
and America’s Living Oceans: Charting a Course for Sea Change, Pew Oceans Commission http://www.pewtrusts.org/ideas/ideas_item.cfm?content_item_id=1635&content_type_id=8&issue_name=Protecting%20ocean%20life&issue=16&page=8&name=Grantee%20Reports
5 Personal correspondence, D. James Baker, May 2, 2007
6 The Rising Tide: Assessing the risks of climate change and human settlements in Low elevation Coastal Zones. Gordan McGranahan, Debra Balk, and Bridget Anderson in Environment and Urbanization April 2007 http://sedac.ciesin.org/gpw/docs/McGranahan2007.pdf
8 Sea-Level Rise & Global Change: A Review of Impacts to U.S. Coasts, Executive Summary Prepared for the Pew Center on Global Climate Change, February 2000, By: James E. Neumann, Industrial Economics, Inc, Gary Yohe, Wesleyan University Robert Nicholls, Middlesex University Michelle Manion, Industrial Economics, Inc. Pew Center on Climate Change
9 Impacts of Climate Change in the United States, THE POTENTIAL IMPACTS OF GLOBAL WARMING ON OUR COASTS AND OCEANS Critical Findings for Coastal Areas and Marine Resources from the First National Assessment of the Potential Consequences of Climate Variability and Change-- An overview prepared by Susanne Moser, Ph.D. (Union of Concerned Scientists) -- http://www.climatehotmap.org/impacts/coastalareas.html.
12 Climate Change and Oceans: Consultative Group on Biological Diversity (CGBD) Mark J. Spalding
13 Climate Change Impacts on the United States The Potential Consequences of Climate Variability and Change
Overview: Alaska, by the National Assessment Synthesis Team, US Global Change Research Program. http://www.usgcrp.gov/usgcrp/Library/nationalassessment/overviewalaska.htm
14 Climate Change and Oceans: Consultative Group on Biological Diversity. Mark J. Spalding
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