This
map is provided by the United States EPA and shows the changes in the amount of dissolved aragonite in ocean surface waters between the 1880s and the most recent decade. Aragonite is a form of calcium carbonate, a base, which many marine mammals such as coral and mollusks use to build shells and skeletons. Increasing ocean acidification due to the absorption of atmospheric CO₂ decreases the amount of minerals available for marine life to use. Although the change is greatest in the tropical regions (red-orange), acidification in the Arctic sea (yellow-green) is of greater concern to biologists since those waters have less aragonite to begin with.
The Arctic Ocean is absorbing carbon dioxide at a rate previously unknown. The top 100 meters is now about 35% more acidic that it was at the start of the Industrial Revolution. Such a huge change could wipe out large numbers of herring, cod and capelin as well as plankton and crabs. The entire marine food chain including humans at the top of it could collapse. A researcher for the Norwegian Institute for Water Research
told the
The Indpendent that sea urchins are particularly sensitive to acidification and they are a major food source for walruses.
Some planktons are also acid sensitive and provide food for fish and whales. These are among the prey species of the Inuit living in Alaska, Canada, Greenland and Chukotka, Russia. Now there is more fresh water flowing into the sea because of the melting ice cap. Chemically, fresh water is less able to neutralize CO₂ absorption. And more CO₂ is being absorbed because the rapidly shrinking ice cap exposes a greater area of the sea directly to the atmosphere. The daily mean concentration of carbon dioxide in the atmosphere
reached a record 400ppm last week according to NOAA*. No imagined
ghoul could devise a
more deadly "triple whammy" against life on Earth.
Perhaps the most controversial chart in recent climate science is this one, the so-called "hockey stick" of temperature change in the northern hemisphere over the millennium just elapsed:
When first published by Michael Mann
et al in 1999 it did not stir much controversy, but then it was featured by the UN's Intergovernmental Panel on Climate Change in its
third Assessment Report. Mann was immediately attacked by climate deniers. Even Congress demanded his data and other information including the computer code used to run his model. Eventually in 2005 the National Academy of Science vindicated the study's results: the "hockey stick" shape of the graph represented good science, and concluded that the unprecedented late 20th Century warming is supported by an array of evidence. Mann projects there will be an 8℉ increase relative to the 1961-90 mean by 2100. This movie is called "Prognosis Negative" unless humans change the plot. Americans cannot handle the truth; maybe that is why the
New York Times shut down its environmental desk.
*this level of atmospheric carbon dioxide was last reached 3 million years ago during the Pliocene when summer temperatures were about 8℃ warmer than today.
