Press Release: Global Warming Expected to Further Degrade Coral Reef Systems

For Immediate Release:
February 13, 2004
Contact:  Katie Mandes
(703) 919-2293

Global Warming and Coral Reefs

Global Warming Expected to Further Degrade Coral Reef Systems

Washington, DC — Coral reefs have the highest biodiversity of any marine ecosystem, providing important ecosystem services and direct economic benefits to the large and growing human populations in low-latitude coastal zones.  One recent estimate valued the annual net economic benefits of the world’s coral reefs at $30 billion. But human activities including development in coastal areas, over-fishing, and pollution have contributed to a global loss approaching 25 percent of these valuable ecosystems.  Global warming is expected to further contribute to coral reef degradation in the decades ahead.  

A new Pew Center on Global Climate Change report, Coral Reefs & Global Climate Change: Potential Contributions of Climate Change to Stresses on Coral Reef Ecosystems, authored by Drs. Robert W. Buddemeier, Joan A. Kleypas, and Richard B. Aronson, outlines the likely impacts of climate change and global warming over the next century to coral reef systems both in U.S. waters and around the world. The report reviews the published literature in an effort to analyze the current state of knowledge regarding coral reef communities and the potential contribution of future climate change to coral reef degradation and loss.

The report concludes that recent global increases in reef ecosystem degradation and mortality (the “coral reef crisis”) are exceeding the adaptive capacity of coral reef organisms and communities.  The severity of this crisis will only intensify with future changes in the global climate.    

“Coral reefs are striking, complex, and important features of the marine environment,” said Eileen Claussen, President of the Pew Center. “If we fail to act, the destruction of these rare and important ecosystems will continue unabated, threatening one of our world’s most precious natural resources.” 

Other major findings from the report include: 

Climate and localized, nonclimate stresses interact, often synergistically, to affect the health and sustainability of coral reef ecosystems.  Increases in ocean temperature contribute to coral bleaching episodes that cause coral mortality and stress, while future increases in atmospheric carbon dioxide may limit coral growth.  In addition to their direct effects, these stresses also act to degrade coral reefs by increasing their susceptibility to pollution, over-fishing, predation, and disease.  

Coral reef alteration, degradation, and loss will continue for the foreseeable future, especially in those areas already showing evidence of systemic stress.  There is no doubt that continued global warming will cause further degradation of coral reef communities.

The effects of global warming on global coral reef ecosystems will vary from one region to another.  Although climate change has the potential to yield some benefits for certain coral species in specific regions, such as the expansion of their geographic ranges to higher latitudes, most of the effects of climate change will be harmful rather than beneficial.   

While the net effects of climate change on coral reefs will be negative, coral reef organisms and communities are not necessarily doomed to total extinction.  The diversity of existing coral species, the acknowledged adaptation potential of reef organisms, the spatial and temporal variations in climate change, and the potential for human management and protection of coral reef ecosystems all provide scope for survival. 

Multiple environmental management strategies, from local to global, will be necessary to ensure the long-term sustainability of the world’s coral reef ecosystems. Efforts to reduce emissions of greenhouse gases that contribute to global warming can reduce the risk of future bleaching events and moderate changes in ocean chemistry.  Marine protected areas will protect coral reefs from nonclimate stresses and enable coral reefs to better adapt to the effects of global climate change.  

Part of “Impacts” Series:

Coral Reefs & Global Climate Change: Potential Contributions of Climate Change to Stresses on Coral Reef Ecosystems, was prepared for the Pew Center by a team of U.S. experts on coral reef ecosystems including Drs. Robert W. Buddemeier, Kansas Geological Survey; Joan A. Kleypas, National Center for Atmospheric Research; and Richard B. Aronson, Dauphin Island Sea Lab.  It is the tenth in a series of Pew Center reports examining the potential impacts of climate change on the U.S. environment.  Other Pew Center reports focus on domestic and international policy issues, global warming solutions, and the economics of global warming. 

A complete copy of this report and other Pew Center reports can be accessed from the Pew Center’s website:


The Pew Center was established in May 1998 by The Pew Charitable Trusts, one of the United States’ largest philanthropies and an influential voice in efforts to improve the quality of the environment.  The Pew Center is an independent, non-profit, and non-partisan organization dedicated to providing credible information, straight answers, and innovative solutions in the effort to address global climate change.  The Pew Center is led by Eileen Claussen, the former U.S. Assistant Secretary of State for Oceans and International Environmental and Scientific Affairs.