At the Climate Summit in Madrid, the International Union for Conservation of Nature recently released a report stating that the amount of oxygen in the ocean has decreased by two percent between 1960 and 2010. The report was penned by 67 scientists from 17 countries, nearly all of whom found evidence linking this deoxygenation to climate change and other human activities.
A two percent reduction in oxygen over fifty years may not seem like a lot, but it is an unprecedented rate of decline for the ocean, causing the sea to warm and acidify at a record speed. Being a body of salt water, the oceans respond to such elemental losses differently than the surface would. Dr. Dan Laffoley, one of the report’s editors, explained to The New York Times that if the heat absorbed by the ocean in the last fifty-five years went into the atmosphere instead, then the surface world would experience a roughly 65 degree (Fahrenheit) increase in global temperatures.
Furthermore, the two percent figure is only an average; oxygen levels are not uniform across the entire ocean. Some areas have a healthy amount of oxygen, but it is not evenly distributed. According to the journal Science, certain tropical waters have found a 40 to 50 percent drop in oxygen.
Most of the ocean’s oxygen is actually getting condensed towards the surface. In a self-perpetuating cycle, deoxygenation makes the water warmer, and warmer water is more buoyant. Therefore, the O2 floats to the top, but it comes at the expense of deeper waters that end up gasping for air. Likewise, when the water is warmer, marine life actually uses the reduced oxygen at a faster rate because all the creatures are vying for each breath.
Without adequate oxygen in the ocean, its vast species cannot survive. If they want to keep sustaining themselves, they have to change their behavior. This means altering migratory patters, diets, and habitats. When one species deviates from its typical behaviors, it can jeopardize entire food chains and ecosystems. Given the surplus of oxygen near the surface, for example, more animals are moving towards higher waters, oversaturating these environments with competing and invasive life-forms.
The main solution that the scientists offer for this issue principally involves reducing greenhouse gas emissions around the world. The ocean is the world’s largest natural carbon drain, but it is now becoming overburdened and overheated, making it incapable of holding as much oxygen or effectively doing its job. As another side effect, warm water also takes up more space through thermal expansion, so deoxygenation in the ocean actually accelerates sea level rise as well.
This report should be a reminder to world leaders at the UN Climate Conference that nature is not expendable in the fight against climate change. Preserving our oceans and forests is an essential element in protecting the human race. These landscapes mean more than just animals and plants. It is these very ecosystems and everything in them that give us the privilege of living in an environmentally sound world. We should not take them for granted, for an ocean ruined by humans will eventually lead to a ruined humanity.