Rising sea levels are a well-documented phenomenon in scientific and political circles alike, but there is another troubling problem beneath the surface of the world’s oceans. Sometimes dubbed ‘climate change’s equally evil twin,’ ocean acidification is a consequence of excess atmospheric CO2. Unlike city smog, ocean acidification is easy to ignore; anyone living inland is unlikely to see or feel its presence. Yet in recent years, acidification has accelerated at an alarming rate. Island nations and those most dependent on oceanic industries such as fishing are already feeling the economic effects, and political ramifications may be close behind. The United Nations already recognizes the phenomenon’s potential impact on international affairs, citing it as a risk to sustainable development, food security, and international political stability. The world’s oceans are a uniquely international interest, and understanding the threat posed by acidification will be essential to the international community going forward.
What is ocean acidification?
The Earth’s oceans are estimated to absorb at least 25% of the CO2 produced by human activity, an amount equivalent to 22 million tons per day. Oceans are essential to moderating atmospheric warming by absorbing CO2 which would otherwise remain in the air. Yet this service comes at a cost. Dissolved carbon dioxide chemically reacts with seawater to form carbonic acid, lowering seawater pH (making the water more acidic). The reaction also depletes the ocean’s supply of calcium carbonate ions, rendering organisms unable to build strong shells or skeletons. Affecting marine life ranging from plankton to oysters, without calcium carbonate even coral polyps are unable to form the shell which enables them to survive and reproduce to form a reef. The importance of the preservation of the world’s coral reefs and the dire threat they face was recently highlighted by the team of the Netflix documentary Chasing Coral. Underwater cameras were able to record a time-lapse of a phenomenon called coral bleaching. During coral bleaching, coral slowly expels the algae it depends on (turning white in the process) in reaction to hostile water conditions including acidity and warmer water temperature. While coral can sometimes recover from bleaching, it takes a minimum of a decade, and mass bleaching events are becoming more common. Back-to-back bleaching events in 2016 and 2017 have hit two thirds of Australia’s Great Barrier Reef, and reefs in the Atlantic aren’t faring much better. Without time to recover, coral reefs could soon be lost forever.
Why is coral important?
Coral reefs form complex ecosystems of their own, supporting organisms ranging from plankton at the bottom of the food chain to larger predatory fish, including sharks. Covering less than 0.1% of the Earth’s surface, coral reefs are estimated to support more than 25% of the world’s biodiversity. Coral death has enormous consequences for organisms all the way up the food chain, including people who rely on seafood as a main component of their diet. Additionally, the die-off of coral has potentially devastating economic impacts. In Queensland, Australia, experts from Australia’s Climate Council have estimated reef loss could mean 1 million fewer visitors, endangering up to 10,000 jobs and draining $1 billion annually from the economy. Tourism is not the only industry under threat. Fishing is an important source of income worldwide, and forms the backbone of certain particularly vulnerable economies. In the small island nation of Seychelles, 15% of the population is employed in fishing or fishing-related fields. Nations with a heavy reliance on fishing and agriculture tend to be among the world’s poorest, leaving millions of already vulnerable people facing food insecurity and a potential loss of livelihood due to ocean acidification.
Wealthier nations are also threatened by coral reef loss and ocean acidification in general. Coral reefs serve other purposes important to humans, including acting as a breakwater (preventing flooding and minimizing storm damage), and as a source for the production of so many human medicines coral reefs are termed the ‘underwater pharmacy.’ Biological substances found on coral reefs are essential to the development of pharmaceuticals ranging from asthma medication to experimental cancer drugs.
Oceans and international affairs
Ocean acidification has enormous potential impacts for global politics and international order. Economic distress can often breed political instability, a threat to both domestic governments and international bodies like the United Nations. As coastal areas become more inhospitable, some coastal residents will be forced to leave their homes and move inland, becoming climate refugees. Furthermore, there is only so much CO2 the ocean can absorb before it reaches a threshold. When that happens, CO2 will have nowhere to go but the atmosphere, accelerating global warming and exacerbating existing climate problems to affect virtually all of Earth’s population.
While some scientists are becoming discouraged by the rapidly increasing acidification of oceans and the failure of governments to respond, others continue to push for a radical reduction of greenhouse gases. While the 2015 Paris Agreement was a crucial step forward in the international movement to decrease emissions, more needs to be done by both governments and the private sector if there is any hope of reversing the damage done to oceans. Lesley Hughes of Australia’s Climate Council speaks for a growing community of scientists and policy makers when he claims it a false dichotomy to ‘pit the environment against the economy,’ and insists, ‘this is not just an environmental issue.’ The oceans are perhaps the most distinctly global feature of the Earth, essential to the success of all nations no matter where they are geographically situated. Without oceans, life on Earth simply would not exist. Commitment of individual nations is not enough; preserving the world’s oceans is an international responsibility, and requires international action if there is any hope of leaving a healthy planet for the next generation.