World Wildlife Fund

Our Endangered Oceans
By Dr. Richard Moss

Many of the impacts climate change will have on people and land have been widely reported in the news media: fewer cold spells, more heat waves. More drought, less freshwater. More intense hurricanes, more frequent storm surges, more coastal flooding. But the impact on marine life has been less well reported, even though this is where some of the most important impacts are already showing up.

Climate change is warming the surface of the sea, producing changes in ocean currents, and causing the sea level to rise. These and other impacts of climate change on our natural world are undeniable and unsustainable. Ultimately, the effects will be seen in changes in global food supplies and local and regional economic stability.

Some local fishermen are already having to follow fish populations that either go deeper into the ocean or migrate toward the poles in search of cooler, life-sustaining water. Fish are more sensitive to temperature than many animals: Each species has a preferred range of temperature and they do not survive too far outside that range.

Fish Catch-22 Fish in warmer water are caught in a bind: As they adapt, their metabolism speeds up, they grow more quickly (although often to a smaller adult body size), and they need more food and more oxygen to support their higher metabolism. At the same time, as the temperature of the water increases, the amount of oxygen it contains decreases. Many fish experience what is called an "oxygen squeeze' - need goes up and supply goes down, both phenomena brought on by the same cause.

The solution to this squeeze is to relocate to cooler waters. Pollock, the most widely used food fish in the world, has moved as much as 500 miles north in the Bering Sea, seeking cooler summer waters. catfish and trout, freshwater species, are starting to move north in the U.S. Southeast Rivers and Streams. We're also seeing significant reductions in the populations of seabirds and marine mammals and lower fish harvests due to a combination of stresses including climate change and overfishing.

Climate Change: The Impacts These and other anticipated impacts on ocean ecosystems were summarized last year in Climate Change 2007: Impacts, Adaptation and Vulnerability, a major assessment of research by the Intergovernmental Panel on Climate Change (IPCC), of which I have been a part since 1993. This report concludes that climate change can affect marine ecosystems in many ways, among them raising surface water temperatures, reducing the extent of sea ice, and raising sea levels, which tend to be the effects most often covered by the media.

However, climate change can also alter the chemistry of the water with regard to its salinity and acidity and it can change the way water in the ocean tends to form layers of different temperature or salinity. It can affect ocean currents, and reduce upwelling, in which deep, cold water rises to the ocean's surface, bringing with it the nutrients necessary to phytoplankton, the organisms at the base of the oceanic food web. As with any other structure, if the base is at risk, the entire structure is at risk. In this case, the complex balance of marine life is ultimately dependent on the health of these organisms.

Looking across all levels of marine life, a wide variety of biological responses are expected to take place by the year 2050. Examples include dramatic reductions in the extent of the biologically significant marginal sea-ice biomes - those areas of the ocean covered by sea-ice on a seasonal basis. We expect approximately 40 percent reduction in the Northern Hemisphere and about 15 percent in the Southern Hemisphere. Equally dramatic are the anticipated collapse of coral reefs and the greater risk of diseases in marine species as the healthy environment in which they live becomes unbalanced and degraded.

Ocean Acidification: A Chemical Imbalance The Earth's oceans are an immense, natural carbon sink - in fact, they are the largest store of carbon, with the terrestrial counterpart, including forests, a distant second. These natural sinks - or storehouses of CO2 - have functioned effectively for millennia, buffering the planet from the abrupt changes due to greenhouse gases. But today, CO2 is increasing in the atmosphere faster than the sinks, including the oceans, can take it up. Enhanced uptake of CO2 from the atmosphere has lowered the average pH of the ocean (it has increased the ocean's acidity). In fact, by 2100 the ocean very likely will be more acidic than at any other time during the last 20 million years.

The acidification of seawater is driving a decline in the amount of carbonate ion. Carbonate ion is needed to make aragonite and calcite, the two forms of the chemical compound calcium carbonate that are used by many marine organisms to build shells and skeletal material. Aragonite is more soluble than calcite. Consequently, the species that depend on it - such as corals and molluscs - are most at risk.

The Corals and Pteropods: Acidification's Bellwethers The consequences of acidification extend well beyond direct effects on calcification by marine organisms, although that is among the most serious threats. More acidic water can have a major impact on respiration in some species, such as squid.

Wide-ranging effects will cascade through marine ecosystems. While polar bears have become the iconic species for melting sea ice, coral reefs and pteropods are icons for the impact of climate change in the water. The swimming pteropod, a predatory sea snail, builds its shell through calcification. Changes in the health, distribution and abundance of this species serve as an early warning of similar impacts on many other ocean animals that build their shells and skeletons through calcification. The implications reach even further, to the wide number of species that feed on them. Coral reefs are home to as many as 2 million marine species and source of 25 percent of the global fish catch in developing countries around the world. Corals use calcification to create their skeletons, the structures we see in coral reefs.

While the full consequences of ocean acidification have not yet been studied, we have enough knowledge on which to base a signal for significant concern. As we draw more attention to the issue, we hope to increase support for research, as we need to rapidly develop a much better understanding of the impacts of high concentrations of CO2 in the oceans.

The Double Whammy: Climate Change and Ocean Acidification Taken alone, either of these forces threatens the ecological balance of the oceans that we have come to depend on, in particular coral reefs and the thousands of species that live in and around them. Taken together, they constitute an emergency situation. Sea temperatures are warmer and acidity and carbonate-ion concentrations are lower than they have been for at least 420,000 years. The rates of change of CO2 in the atmosphere and of global temperatures during the last century are 100 to 1,000 times greater than those experienced during that period. The rate of change is critical since modern corals may not be capable of adapting quickly enough. One of the most dramatic impacts on coral reefs is "coral bleaching' where, in response to high water temperatures, corals lose essential symbiotic algae and/or those algae lose some of their photosynthetic pigment.

The symbiotic algae are essential to the reefs and if the bleaching is severe enough for long enough the coral dies. Bleaching events have become more common in recent decades and are now happening regularly around the planet. WWF experts have seen them firsthand in all of the tropical marine ecoregions where we work. WWF-supported research on Caribbean reefs showed they suffered the worst bleaching and mortality event on record in 2005, which also was the hottest year on record.

Caribbean reefs suffered the worst bleaching and mortality event on record in 2005, which also was the hottest year on record.

Compounding the problem was the damage inflicted by waves during that year's very active hurricane season. An important part of the work of the IPCC involves assessing the impact of different levels of CO2 in the atmosphere, measured in parts per million (ppm). Today's CO2 level is 380 ppm, compared to a pre-industrial level of about 280 ppm. In a scenario based on low CO2 emissions, that level is projected to reach 550 ppm by 2100, 45 percent higher than today. This would also be well beyond the 480 ppm level at which the amount of carbon coral reefs can take in becomes negligible or even reverses. At concentrations of 550 ppm, the consequences would be extreme and the calcium-based structures of coral reefs could erode.

WWF's Approach WWF is deeply and urgently engaged in the campaign against climate change. I joined the organization in November 2007 and have teamed with WWF colleagues across our global Network to address the causes and effects of this growing threat. We have dedicated climate change experts working in more than 50 countries and have focused our efforts where we will have the greatest impact.

We actively support responsible policy making in all areas that connect to climate change and we are working with business and industry to reduce carbon dioxide emissions. We're protecting marine waters and tropical and temperate rain forests around the globe for their many values including their roles as carbon storehouses. And wherever the impacts of climate change are already a clear and present danger, WWF teams are working with affected local communities to protect their natural resources and themselves In the Caribbean, our scientists are at work identifying which factors can make coral reefs more resistant to global warming and recommending management actions to address these factors.

In the Bering Sea, WWF has teamed closely with Alaskan and Russian scientists to assess the implications of climate change on polar bears, who live on land and in the sea. We have heightened our efforts to protect the bears and their habitat. Projects are under way in Tanzania and Cameroon to increase the resilience to climate change of shorelines. We are restoring and protecting mangrove forests that protect shorelines and nearby communities by reducing the impact of the increasing intensity of severe weather events resulting from climate change. We are studying how healthy mangroves also protect coral reefs from pesticide and sediment runoff from the land.

The Energy Arena About two-thirds of the greenhouse gases currently being released into our atmosphere and oceans comes from the energy sector through the use of fossil fuels. And because China is experiencing the world's fastest growth in energy use, we have run an energy efficiency campaign in Beijing and are working on a plan for the country's electricity sector, helping them chart a more sustainable path as their economy grows. We also helped set up Southeast Asia's first wind power plant and a powerful coalition of industry, political and social groups to work for a reliable national law on renewable energy.

In 2007, WWF launched an innovative global partnership with Intel, Google, HP, Microsoft, Dell and close to 100 other organizations: the Climate Savers Computing Initiative. The goal of the new broad-based environmental effort is to save energy and reduce greenhouse gas emissions by setting aggressive new targets for energy-efficient computers and components, and promoting the adoption of energy-efficient computers and power management tools worldwide.

Mitigation and Adaptation At WWF, experts address the need to reduce or mitigate human induced causes of climate change and the need to respond or adapt to the wide-ranging effects already being experienced by people, places and wildlife around the world. WWF recently held our second "Climate Camp,' a five-day program where conservation scientists and practitioners can interact with experts and peers to design adaptation project plans and develop resource networks to support the work. In addition to WWF staff from around the world, participants include colleagues from other conservation organizations and governments.

The first Climate Camp, in 2006, attracted more than 130 people who collaborated on strategies to address impacts in places ranging from coastal regions to alpine mountains to tropical forests. The result: a portfolio of 22 new projects across close to 50 countries. To date, 15 of these projects have been funded. The 160 attendees at Climate Camp 2008 focused on temperate, polar and tropical marine ecosystems; temperate and tropical forests; and scrubland, grassland and montane habitats. Their project proposals are now under development.

Combining WWF's growing scientific understanding of climate change - both mitigation and adaptation - with that developed by the 20 years of scientific collaboration through the UN Intergovernmental Panel on Climate Change, we are in the best possible position to produce lasting results across our 19 priority areas and, by extension, around the world.

At the UN Climate Change Conference
Bali, Indonesia, provided an evocative backdrop for the recent UN climate change conference. Delegates from 187 nations came together for two intense weeks of negotiations to gain agreement on a comprehensive, legally binding United Nations framework to tackle climate change. WWF was an active participant in the climate debate. The WWF climate team, many of whom also served as official delegates representing their respective countries, played a central role in reaching an agreement. In addition to the formal negotiations, WWF sponsored many side events and activities designed to share information and influence the negotiators, such as

• Issuing a new report stressing the impact of weather records broken in 2007 as the result of global warming
• Releasing a report that detailed the many ways climate change is speeding up the destruction of the Amazon
• Emphasizing the threats facing the penguin population of Antarctica due to global warming in the report Antarctic Penguins and Climate Change
• Announcing Earth Hour, a global action to take place March 29, 2008, in which 180 cities and communities would turn out their lights for one hour to symbolize their commitment to finding solutions to climate change

Moving Forward The Bali conference marked the beginning of a two-year negotiating process. While most environmental organizations - including WWF - felt the Bali action plan fell short, there was widespread relief that the conference produced enough agreement on the essential elements to provide a mandate and roadmap for future negotiations. The goal is to complete negotiations by 2009 so that a new treaty can take effect when the Kyoto Protocol's first commitment period expires in 2012. WWF will continue to be closely involved in future conferences, working to slow climate change and leave our natural heritage intact for future generations.

Previous Spotlight Features