Coral Vulnerability
Published by the Natural Resources Defense Fund
Coral reefs worldwide are threatened by rising sea surface temperatures and ocean acidification, and humans will acutely feel this loss in a high carbon future.
Who is likely to be most harmed by coral reef loss from these global stressors is the subject of a recent analysis I coauthored, “Coral Reefs and People in a High CO2 World: Where Can Science Make a Difference to People?” published yesterday in the journal PLOS One.
In our new study, led by Duke University and the Université de Bretagne Occidentale, we built on previous analyses to look at ecosystem services that coral reefs provide to humans. Coral reefs are inextricably intertwined with the people who live near them: through tourism, as storm buffers, and as a critical source of food and shelter for the fish many communities depend on for a source of protein. Our analysis looked at storm protection and food from fisheries. (We were not able to assess loss of income from highly-lucrative coral reef-dependent tourism for this study due to inadequate global data sets).
To evaluate storm protection, we looked at the number of people living at low elevations adjacent to a protective coral reef to determine what proportion of a country’s population would be vulnerable if coral degraded. We analyzed fisheries data to determine which countries are most dependent on coral reef fish for food and income.
Our research found that Southeast Asia, Americas, Oceania, and Eastern Africa (i.e., the brown countries on the map below), are all places that are highly dependent upon the ecosystem services provided by coral reefs.
When we layer on the one-two punch from climate change and ocean acidification, we see the following areas at highest risk: Northwestern Australia, southern Indonesia, the Coral Triangle countries of Southeast Asia, and Western Mexico. These all have high human coral reef dependence and face serious CO2-related threats (See map where the brown meets red and orange). By 2050, these regions are likely to experience coral reef bleaching and reef loss that impacts fisheries and shoreline protection, jeopardizing lives and economic prosperity.
So, why issue this warning? How is this information useful? For one, countries that are especially dependent on coral reef services may want to invest in mitigation and adaptation strategies. For example, these countries could begin to identify populations or species of corals that are most resilient to these changes and begin to propagate them. They may want to invest in local mitigation measures such as seagrass restoration. In many cases, better ocean management could also delay these effects through increased ecosystem resilience.
Organizations such as non-governmental organizations, nonprofits, and labor and trade organizations that represent people who would be most severely impacted by coral loss can also use this information to advocate for action, including the collection of information on sea surface temperatures and ocean acidification in these regions, and policy changes to combat these threats.
All countries, not just coral-dependent nations, should hear this as another call to address the severity of the threats posed by runaway carbon pollution. The United Nations Framework Convention on Climate Change (UNFCCC) has unfortunately remained relatively quiet on the serious threat climate change and ocean acidification are posing to our oceans, as I wrote in a previous blog post, LINK: https://www.nrdc.org/experts/lisa-suatoni/signing-international-climate-agreement-boon-our-oceans.
As I explained in the post, the Paris framework as currently written does not adequately address ocean acidification. The agreement permits emission reductions in terms of ‘CO2 equivalencies’, including other greenhouse gases, such as methane. However, solving the problem of ocean acidification will require reductions in carbon dioxide emissions, specifically. Reductions in other greenhouse gases will do nothing to slow ocean acidification. In addition, the Green Carbon Fund, the financial mechanism of the UNFCC which invests in climate-resilient development, might not issue grants for ocean acificiation. With this in mind, the next re-evaluation of the Paris agreement should consider the harmful effects of changing ocean chemistry in addition to the impacts from global warming.
I hope that this new research, as it offers yet more evidence that a high carbon future puts human lives at risk, will further spur leaders to global climate action.
Read the full article at: https://www.nrdc.org/experts/lisa-suatoni/coral-vulnerability
