June 12, 2015
People often joke that oceans are nature’s toilet, but this metaphor compares oceans to the wrong bathroom appliance. A more accurate comparison would call these large bodies of water sinks, due to their incredible ability to absorb one-third of all human carbon emissions.
For tens of millions of years, the amount of carbon dioxide in the atmosphere was relatively stable. However, emissions began to dramatically increase after the start of the Industrial Revolution—having risen 39 percent since the late 1700s.
This increase has been driven by two closely-linked trends: an explosion of population growth and the transition to fossil fuels as the dominant energy source. As population grew exponentially, so did the demand for energy. This high energy demand was met by burning increasingly more fossil fuels, which resulted in unprecedented carbon dioxide emissions.
More carbon in the atmosphere means more carbon in the oceans. And, since the late 1700s, oceans have absorbed 525 billion tons of carbon dioxide, causing seawater acidity to increase by thirty percent.
Ocean acidification has scary consequences for marine ecosystems and the millions of people whose livelihoods depend on them. Shell-forming species, including corals, suffer as high levels of acidity corrode their shells. Because these at-risk species provide habitats and food for other species, their extinction could have devastating effects all the way up the food chain.
Worse yet, acidification is causing oceans to become less effective at absorbing carbon. This means that, for every ton of carbon dioxide released, a larger portion will remain in the atmosphere. More CO2 in the atmosphere will exacerbate climate change, further decreasing oceans’ ability to absorb carbon.
Climate change is already altering the world as we know it, with especially devastating consequences for people in some of the poorest parts of the world (for example, the recent heatwave in India that killed more than 2,300 people). It is terrifying to imagine the climate consequences as oceans become less effective sinks and even more carbon dioxide remains in the atmosphere.
How can we break this vicious cycle? A recent study by the Bixby Center for Global Reproductive Health found that up to 29 percent of the needed reduction in carbon emissions can be achieved by providing family planning to women who want it in developing countries. This would, in turn, help to stabilize the global population.
Because population growth and energy use are intimately connected, it makes sense that one of the best ways to reduce carbon emissions and protect the world’s oceans is to give women the ability to plan their pregnancies. Sounds like a win-win solution to us!