By John Lawrence
As the amount of carbon dioxide pumped into the atmosphere continues to increase, a certain portion of that gets absorbed by the oceans. This year alone some two and a half billion tons of CO2 will be absorbed by the oceans. That represents seven pounds pumped into the seas by every American.
Oceans cover seventy percent of the earth’s surface, and everywhere the oceans and the atmosphere come into contact there is an exchange of gases. When this exchange is in balance, there is no problem. But when the atmosphere’s gaseous composition has been changed, which it has since the industrial revolution, the exchange becomes lopsided. More CO2 goes into the ocean than comes out.
Since the start of the industrial revolution, humans have burned through enough fossil fuels to add 365 billion metric tons of carbon to the atmosphere. Deforestation has added another 180 billion tons. Each year we add another nine billion tons or so, and that amount has been increasing 6 percent annually. Today the concentration of carbon dioxide in the air is 400 parts per million (PPM). This is higher than it has been at any time in the last 800,000 years.
If current trends continue, the concentration of carbon dioxide in the atmosphere will be 500 ppm by 2050, double the levels in pre-industrial days. So in a sense, all the progress that civilization has made due to the expenditure of large quantities of energy since 1850 or so has now essentially doomed civilization unless radical changes are made in how this energy is obtained and utilized.
When carbon concentrations reach 500 ppm, there will be a global temperature rise of between three and a half and seven degrees Fahrenheidt. This will trigger world altering events such as the loss of all glaciers, melting of the Arctic ice cap and a sea level rise that will inundate all coastal cities and low lying islands. Already some low lying islands have disappeared. The President of Kiribati is in talks with Fiji’s military government to buy up to 5,000 acres of land in order to relocate the 102,697 people that live in his country. President Tong said that this is their last resort: “Our people will have to move as the tides have reached our homes and villages.”
pH is a measure of the acidity or basicity of an aqueous solution. Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline. Pure water has a pH very close to 7. Thanks to all the extra CO2, the pH of the oceans’ waters has already dropped from an average of 8.2 to an average of 8.1. A drop of .1 means that the oceans are now 30 percent more acidic than they were in 1800.
If business continues as usual, the surface ocean pH will drop to 8.0 by 2050 and to 7.8 by century’s end. At that point the oceans will be 150% more acidic than they were at the start of the industrial revolution. Marine biologists like Jason Hall-Spencer have warned about the catastrophic consequences to marine life if the oceans’ pH reaches 7.8. According to him this represents a tipping point at which the ocean’s ecosystems start to crash.
The ones most at risk are the calcifiers. The term calcifier refers to an organism that builds a shell or external skeleton or, in the case of a plant, an internal scaffolding out of the mineral calcium carbonate. Some examples of calcifiers are starfish, sea urchins, clams, oysters and barnicles. Some species of coral and seaweed are calcifiers. Ocean acidification increases the difficulty for organisms to perform the calcification process in the process of their development. At higher levels of acidification, already existing organisms start to dissolve.
Ocean acidification is dangerous because it will change the makeup of microbial communities. It will interfere with photosynthesis because it will change the amount of light passing through the water. It will also alter the way sound propagates and make the seas noisier. It will promote the growth of toxic algae. There will be a reduction in biodiversity. Microscopic organisms will use up more nutrients leaving less for larger organisms. The equilibrium of the oceans established over many eons becomes unhinged, and many organisms will go extinct.
Eventually, the oceans will reach their capacity to absorb carbon dioxide. At that point the build-up of atmospheric carbon dioxide will accelerate. So far roughly one third of the carbon dioxide that humans have spewed into the air has been absorbed by the oceans – approximately 150 metric tons. Most importantly, it’s the rate at which this process has taken place. This amount has gone into the oceans in just 150 years – a minute measure compared to the eons at which most geophysical changes take place. The current acidification is on a path to reach levels higher than any seen in the last 65 million years, and the rate of increase is about ten times the rate that preceded the Paleocene–Eocene mass extinction. The current and projected acidification has been described as an almost unprecedented geological event.
The oceans’ rising acidfication dissolves shellfish in the Pacific northwest that many Indian tribes depend upon:
It’s a big challenge to tribes in the Pacific Northwest, said Billy Frank Jr. (Suquamish) back in 2010, addressing the 20 tribes that make up the Northwest Indian Fisheries Commission
Its impacts are felt by Native and non-Native communities in Washington State that rely on oysters and shellfish. Disastrous production failures in oyster beds caused by low pH-seawater blindsided the oyster industry in 2010, prompting a comprehensive 2012 investigation by Washington State. Earlier this month Governor Jay Inslee took the issue to the media in order to jump-start climate change action in his state, The New York Times reported on August 3 .
The Quinault Indian Nation on Washington’s coast is part of one of the most productive natural areas in the world and is especially involved in the ocean acidification issue. The rivers in Quinault support runs of salmon that have in turn supported generations of Quinault people. The villages of Taholah and Queets are located at the mouth of two of those great rivers. The Pacific Ocean they flow into is the source of halibut, crab, razor clams and many other species that are part of the Quinault heritage.
The Great Barrier Reef (GBR) off the coast of Australia is in trouble. The largest coral reef system in the world is not growing like it used to. The growth of colonies has slowed by approximately 13% since 1990. Although protected as a marine park for decades, more than half of the coral is dead. Without concerted action, just five to 10 percent of the coral will remain by 2020, according to a 2012 scientific survey.
According to Scientific American:
The most likely reason is climate change caused by increasing carbon dioxide (CO2) and other greenhouse gases in the atmosphere…
The burning of fossil fuels over the past century or so has driven atmospheric CO2 levels from 280 parts per million (ppm) to  ppm—and growing. More than 25 percent of this extra CO2 is absorbed by the world’s oceans and reacts with seawater to form carbonic acid. A rising carbonic acid level means a more acidic ocean.
In 1981 UNESCO declared the GBR a World Heritage Area, calling it “an irreplaceable source of life and inspiration”. It was home to 10 percent of all fish on the planet. But now Australia is proposing to dump 5 million tons of toxic dredging sludge in the region as they go about building a port for the export of coal. Given the perilous health of the reef, which is also facing enormous threats from rising water temperatures and ocean acidity due to CO2 emissions from fossil fuels, scientists are calling for a complete ban on dumping in the GBR or anywhere near it.
The additional threat posed by coal ports and other industrial developments along the coast is so serious that UNESCO warned Australia it would change the reef’s prestigious World Heritage Site designation to a “World Heritage Site in Danger”.
The UNESCO decision is expected mid-2015, which is also when the dredging is scheduled to begin.
We are running geologic history backwards at warp speed. In the magazine Oceanography, Kump and Ridgwell have observed: “It is the rate of CO2 release that makes the current great experiment so geologically unusual, and quite possible unprecedented in earth history. [If this rate continues, it] is likely to leave a legacy of the [current era] as one of the most notable, if not cataclysmic events in the history of our planet.”
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