To many people, our oceans are little more than a great blue expanse of water. To some, they are a source of beauty and enjoyment. And for millions of people around the globe, the oceans are sources of food and jobs in fishing or fish-farming industries. But the oceans are also the anchor for life on this planet. When it comes to global warming, the oceans may be our salvation.
The oceans do much more than provide us with food, employment, and enjoyment. They also absorb much of the excess carbon that humans have been pumping into the atmosphere during industrialization.
The world’s oceans have already absorbed a huge percentage of carbon that would contribute to global warming if it were released into the atmosphere, according to Blue Carbon: the Role of Healthy Oceans in Binding Carbon, a report by the UN Environment Programme, the UN Food and Agriculture Organization, and the Intergovernmental Oceanographic Commission of UNESCO.
The IOC’s Patricio Bernal argues that “the ocean has already spared us from dangerous climate change.” He adds, though, that “each day we are essentially dumping 25 million tons of carbon into the ocean. As a consequence, the ocean is turning more acidic, posing a huge threat to organisms with calcareous structures.” (These organisms include corals, clams, shrimp, and many types of plankton.)
The report finds that protecting and restoring marine ecosystems such as estuaries and mangroves could contribute to offsetting up to seven per cent of current fossil fuel emissions at a much lower cost than technologies to capture and store carbon at power stations. What this means from a global warming perspective is that by simply protecting and restoring these ecosystems, we could achieve 10 per cent of the reductions required to keep the climate from warming by 2º C. These actions would also have numerous other benefits to marine wildlife and fisheries.
The damage we are inflicting on ocean ecosystems has numerous consequences for global warming. Ice at the North and South poles has kept our ocean temperatures relatively stable for millennia. Now, our oceans are absorbing so much additional energy that the ice is melting and the oceans are warming at an ever-increasing rate. If polar ice disappears, the warming trend will escalate because the albedo effect, the reflection of sunlight off bright surfaces like clouds and ice, will decrease. We can only guess how this will affect marine ecosystems and all life on our planet, but we are already noticing changes in the distribution and abundance of species throughout the world’s oceans.
The Blue Carbon report notes that of all living organisms that are able to capture carbon, those that live in the ocean capture more than 55 per cent. Coastal wetlands, marshes, mangroves, and estuaries play an important role in absorbing carbon from the atmosphere. Other life forms in the open ocean assimilate carbon through their diets, which is then stored in the sediments of the deep ocean when the life forms die and sink to the bottom. This carbon will be stored for millennia.
…
David Suzuki, The Tillsonburg News, 15 December 2009. Article.
