Ocean Acidification, Global Warming's Evil Twin, is Killing the Oceans
We used to think that the ocean was so vast that there was no way that any act of humans would ever affect it. Now we know differently -- but is it too late?
Oceans absorb 25% of the carbon dioxide that we put into the atmosphere. This is quite a favor to us. Without the oceans Earth would be a much hotter planet than it currently is. The oceans cover two thirds of the world's surface and provide twenty percent of the protein that we eat every day, as well as countless jobs that support life on land.
For all this, we are giving the oceans absolutely nothing but abuse.
According to chemical oceanographer Triona McGrath, the ocean has been undergoing a long negative change in pH (the acid/alkaline balance of the water) since the rise of the Industrial Revolution. Low pH means high acidity. Carbon dioxide dissolves in seawater -- that's good news. The bad news: As a result of absorbing of all of this carbon dioxide, the pH of seawater goes down, meaning the acidity increases.
Seawater acidity has been rising steadily since the start of the Industrial Revolution at the exact same rate as carbon dioxide has been rising in our atmosphere. What a coincidence! It seems like man is having a major impact on the oceans after all. We probably should have figured this out after nearly killing all the whales in the North Atlantic so we could read by lamplight. This increase in carbon dioxide has caused a 26 percent increase in ocean acidity since pre-industrial times. According to McGrath, the oceans are expected to rise in acidity by 170 percent by the end of this century.
We can see the effects of rising acidity in a number of ocean species by doing simple experiments involving seawater and the given ocean species. When the sea butterfly, which is food for a whole host of animals from krill to salmon to whales, is exposed to the type of acidity that we are expected to see by 2100, the shells of these arthropods almost disappears completely after only 45 days. If this is the type of ocean acidity we can expect in the year 2100, we are not likely to have the type of ocean organisms that we currently have in the oceans today.
This causes a ripple effect throughout the food chain that is unknown to scientists at this time. What is known is that the process of ocean acidification can be slowed by slowing the rate and amount of carbon that we put into the atmosphere. This means a reversal of current trends in burning fossil fuels.
Carbon ions are also needed by certain organisms to build shells. Organisms like mussels and crabs need these carbon ions in order to build their shells and survive. Coral also needs this ion in order to survive. With the rising acidity of the ocean's temperatures, these ions are disappearing from the ocean and these organisms will have a hard time surviving.
The projected increase in acidity would be by far the fastest and most dramatic increase in the past 55 million years. 55 million years ago another change in the ocean's acidity occurred through a natural phenomenon that was much slower than the process that is occurring today. That change in the oceans acidity brought about a mass extinction of a wide variety of marine life. It is unknown what effect this quick change in acidity will have on certain ocean organisms.