Seventy-five percent of the world’s coral reefs will be at risk of death or extreme damage within 20 years, and 95 percent of the world’s reefs will be at risk by 2050, if human-caused climate change continues unabated, according to a major new study released this morning.
The study, “Reefs at Risk”, was released by the World Resources Institute, an environmental research think tank, in collaboration with 23 other international academic, government, and nongovernmental research agencies, including NASA, the National Oceanic and Atmospheric Administration, and the United Nations Environment Program.
The findings, which represent the most comprehensive study to date on the effect of warming seas on one of the planet’s most valued ocean resources, are expected to have a profound impact within the scientific community, and could ultimately serve to give advocates of climate change policy a powerful data point for building their case. But in Washington, they come at a moment when the political climate could hardly be more hostile to global-warming policies, which would require major new regulations on the fossil-fuel pollution emitted by vehicles, manufacturers, oil refineries, and coal-fired power plants.
Last year, efforts to pass a comprehensive cap-and-trade climate-change bill died in the then-Democratic controlled Congress. Now tea party Republicans have made the Environmental Protection Agency’s new climate rules among their top political targets, slamming regulations that control fossil-fuel pollution as symbolic of government overreach. Last week, the Republican-controlled House passed a budget bill packed with provisions to handcuff the EPA’s authority to regulate climate change, and to defund a slew of other government programs aimed at researching and preventing climate change. While such a bill would never make it past President Obama’s desk, it would lay down a marker of how far Republicans are willing to go in a battle that will extend throughout the 2012 election cycle.
The reef report’s authors, who make an urgent call for policies to limit greenhouse gas emissions, say they are fully cognizant of the realities on Capitol Hill, as is the rest of the scientific community. What they hope to do over the next two years is keep the spotlight on the scientific reality of climate change, marshalling newer and stronger sets of data to ensure that the case for action is more solid and compelling when the political winds shift in their favor. Climate policy advocates say new, highly reputable, and highly publicized data are necessary to advance their case, especially after Republicans in 2009 launched a campaign to discredit the U.N. Intergovernmental Panel on Climate Change reports, which had been the most frequently cited by global climate policy advocates.
“The political climate in this country is definitely against climate legislation. But lots of evidence is coming up all the time that climate change is real and happening. This is one more argument for looking seriously at greenhouse gases. This is a whole ecosystem at risk,” said environmental policy analyst Lauretta Burke, the reef report’s chief author. She added, “And unexpected things can happen. Look at the pace of what’s going on right now in the Middle East.”
The World Resources Institute led the last comprehensive study of coral reefs at risk, in 1998. That study focused chiefly on local threats, such as overfishing, overdevelopment in coastal regions, and chemical pollutants in waters. Those threats remain, concludes the new report, but by far the greatest threat, and one that compounds the impacts of all the local pollutants, is the rising levels of carbon dioxide in the atmosphere. That has led to rising global temperatures—NOAA and NASA reported that 2010 was the hottest year on record—including warmer oceans. Oceans are also absorbing the atmosphere’s increased CO2, which leads to increased acidity. The increasingly warm, acidic waters weaken coral reefs, making them more vulnerable to the impacts of local pollution, and to bleaching.
“Mass coral bleaching, a stress response to warming waters, has occurred in every region and is becoming more frequent as higher temperatures recur. Extreme bleaching events kill corals outright, while less extreme events can weaken corals, affecting their reproductive potential, reducing growth and calcification, and leaving them vulnerable to disease,” says the report.
“The single greatest growing threat to coral reefs is the rapid increase in greenhouse gases in the atmosphere, including carbon dioxide (CO2), methane, nitrous oxide, and halocarbons,” it concludes. “Since preindustrial times, atmospheric concentrations of all of these gases have increased significantly, and in the case of CO2, which contributes the most to both warming and acidification, concentrations have risen by over 35 percent. During the past 10 years, almost 40 percent of coral reefs have experienced thermal stress at am level sufficient to induce severe coral bleaching.... Under a “business-as-usual” scenario, our models suggest that roughly 50 percent of the world’s reefs will experience thermal stress sufficient to induce severe bleaching in five out of ten years during the 2030s. During the 2050s, this percentage is expected to grow to more than 95 percent.”
The report also includes detailed maps of coral reefs around the globe, taken with satellite and geographic information system technology, comprehensively detailing existing coral damage and pollution levels. The data reflected in those maps is 64 times more detailed than the data in the 1998 report, said Burke.