By burning coal, oil, and gas, human beings have increased the amount of carbon dioxide gas in the Earth’s atmosphere. Since the industrial revolution, levels of the gas have increased by almost fifty percent.
The most well-known problem caused by this is the warming of the climate. But oceanographers have come to realize that it causes other major problems too. About one quarter of the carbon dioxide produced by human activities doesn’t stay in the air. It dissolves in the oceans. Since the industrial age began, atmospheric scientists estimate the oceans have absorbed five-hundred twenty-five billion tons of carbon dioxide, with another twenty-two million tons absorbed every day.
At first, researchers saw this as a good thing, because this absorption slows the buildup of carbon dioxide in the air, and the rate of global climate change. But, absorption of carbon dioxide by seawater causes a chemical change, making the water more acidic. In the past two centuries, the oceans have become thirty percent more acidic, and this will continue to increase.
Marine biologists have found many ways that this harms marine organisms. The changes in the chemistry of the water will make it harder for shelled organisms such as oysters and corals to grow shells or skeletons, and can even cause these structures to dissolve. The effects on some zooplankton, tiny floating organisms which are an important source of food for larger animals, may be particularly important. More acidic water is also stressful to fishes.
Researchers expect ocean acidification to cause species declines, reducing the diversity of life in the sea. This will, in turn, impact human activities such as fishing and aquaculture.
