I attended the 8th Annual Roger Revelle Commemorative Lecture at the Smithsonian on March 5th entitled “What Corals Are Dying To Tell Us About CO2 and Ocean Acidification.” Ken Caldeira, the presenter, spoke to about 500 people in a packed auditorium about the current trends worldwide in coral reef health. He expressed concern that although popular media talks about the effect CO2 has on the air, there isn’t much spoken about the effect CO2 has on the oceans. And the oceans are not an indefinite sink for CO2.
Carbon Dioxide deposits in the oceans and the molecules bind with the water molecules to create Carbonic Acid. If there is too much Carbonic Acid, it can change the pH of water and is corrosive to the shells and skeletons of marine organisms coated or composed of calcium carbonate, such as corals. The acid literally eats away at the organism.
Why is this important? As pollution increases in our global ecosystems, biodiversity is reduced and food chains can be disrupted. In the case of corals, they are the food source, breeding ground, and home for a whole system of organisms, the diversity of which is sometimes compared with rainforests. If the current deposition trend continues, oceans will loose not only corals, but the ecosystem that corals sustain as well.
Visible loss of coral has been recorded worldwide. Though CO2 exacerbates the destruction of corals, it is not the only factor. Eutrophication, temperature changes, and human development have also taken their toll. It will take tens of thousands of years for the oceans to recover chemically to normal levels. The current situation of CO2 deposition in the oceans can be compared with the meteorite theorized to have hit in the Yucatan 65 million years ago that caused a great amount of chemical change in the ocean (along with temperature change) and resulted in a biological impact from which the corals did not recover for 10 million years.
The solution offered by Dr. Caldeira was two-fold. More research must be done on the oceans, we currently know so little about the effects of long lasting events. And we must change our current energy production and consumption. The average American is responsible for producing 120 pounds of CO2 per day, 40 pounds of which deposit in the oceans. This is five times the global average. Natural release of CO2 is 50-70 times less than this. This is yet another reason we as a global community need to take energy production alternatives seriously and move away from our dependency on fossil fuels.
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