Where can science make a difference to people?

Levi Westerveld

By GRID-Arendal

November 10^th, 2016

A new study on the effects of climate change on the world’s coral reefs comes as negotiators from nearly 200 countries gather in Marrakesh to begin implementing the Paris Agreement on Climate Change.

That high carbon dioxide levels in the atmosphere are wreaking havoc on coral reefs is not a new story. The fate of Australia’s the Great Barrier Reef is one example. On the other hand, there have been optimistic studies like one produced by United Nations Environment and GRID-Arendal that look at ways coral reefs could be saved.

The new study – Coral Reefs and People in a High-CO2 World: Where Can Science Make a Difference to People? – appears in the journal PLOS One. It states that as atmospheric carbon dioxide (CO2) levels increase, very few coral reef ecosystems will be spared the impacts of ocean acidification or sea surface temperature rise. This damage will lead to immediate and serious threats where human dependence on reefs is highest.

The new analysis, led by Duke University and the Université de Bretagne Occidentale, suggests that by 2050, Western Mexico, Micronesia, Indonesia, parts of Australia and Southeast Asia will bear the brunt of rising temperatures. Reef damage will result in lost fish habitats and shoreline protection, jeopardizing the lives and economic prosperity of people who depend on reefs for tourism and food.

GRID-Arendal worked with the authors of the study to develop a Story Map highlighting the main findings. The Story Map provides an overview of the study and a platform to visualise the data compiled by scientists in their research. It is available in French and English.

“2016 has been one of the worst years in memory for coral bleaching,” says Linwood Pendleton, the study’s lead author, a senior scholar at Duke University’s Nicholas Institute for Environmental Policy Solutions and an International Chair of Excellence at the European Institute of Marine Studies.

Coral reef loss and its effect on countries that depend on them was the subject of a resolution on sustainable coral reefs management at the second UN Environment Assembly in May this year. The resolution calls on countries to implement ecosystem-based approaches for the sustainable management of coral reefs. Among other things, it encourages the use of marine protected areas and strengthened partnerships with industry, including fisheries, aquaculture and tourism.

The new study builds on previous analyses to identify exactly how people and coral reefs are affected by a high-CO2 future and suggests ways to help deal with changes. The authors mapped human dependence at the country level, focusing on shoreline protection and coral reef fisheries. Simultaneously, the authors mapped the largely unavoidable impacts of increased sea surface temperature and ocean acidification.

Using data from the maps, the study predicts that the countries of Oceania will be among the first to face the greatest environmental stresses from climate change and ocean acidification, followed by the Coral Triangle countries of Southeast Asia and other parts of Australia -- all areas with high dependence on coral reefs.

Countries most likely to experience severe ocean acidification are generally different from those that will experience the earliest onset of coral bleaching. Acidification is projected to be worse for Baja California (Mexico), Japan, China, and southern Australia because they are at the upper and lower latitudinal bounds of coral reef distribution and thus generally in cooler waters that naturally carry more CO2.

“The response of non-governmental organizations, nonprofits, and labor and trade organizations will be critical in mounting a response to the threats posed by warming and acidification because these organizations represent the people that will be most severely impacted by the failure of coral reef fisheries,” said Chris Langdon, a professor in the Department of Marine Biology and Fisheries at the University of Miami.

The authors say policy action to combat the threats of ocean acidification and surface temperature rise must be informed by data and science. But the research community is still doing a poor job of collecting this information where these threats are most substantial for people. Many of the countries most dependent upon coral reefs are also the countries for which we have the least robust data on ocean acidification. This is especially true in the South China Sea, an area of high human dependence and equally high political tensions.

“Better environmental management can help delay the impacts on corals,” says Adrien Comte, a Ph.D. candidate at the Université de Bretagne Occidentale. “But at some point coastal communities are going to have to move to higher ground to compensate for the loss of shoreline protection provided by reefs and find new sources of food to supplement fishing losses.”

The study is available here.

Footnotes

Header: A panoramic image of coral bleaching in the Maldives captured by the XL Catlin Seaview Survey (May 2016). © XL Catlin Seaview Survey / Underwater Earth.

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FootNotes

Header: A panoramic image of coral bleaching in the Maldives captured by the XL Catlin Seaview Survey (May 2016). © XL Catlin Seaview Survey / Underwater Earth.