Ocean acidification is like the Castle Ghost – everyone is scared of it but no one has seen it.
Dozens of learned articles and millions of media words tell us that ocean acidity has increased alarmingly since man started using carbon fuels. The worry is that the carbon dioxide being generated by man’s industry is dissolving in the ocean thus creating acidic water. And the computer models forecast that, by some future date, sea shells and corals will be dissolved or killed by the acidic ocean and/or the associated global warming.
However a close look at the chemistry of the oceans and the evidence provided by past records and present observations reveals that the open ocean is alkaline and never acidic, except locally near active submarine volcanic vents. It is deceptive to suggest that sea life is threatened by “the rising acidity of the oceans”. The oceans are still quite alkaline. Nothing unusual or abnormal has yet been detected. Other conclusions are:
- The pH of the oceans varies naturally from place to place and time to time, depending on temperatures and the activities of plant and animal life. It is impossible to determine a meaningful figure for “average” ocean acidity (pH). It is also impossible to say with any certainty that average ocean pH has changed because of man’s use of carbon fuels. Such “measurements” are an exercise in guided guess-work. (“What would you like the answer to be?”)
- It is a myth that acidic waters necessarily kill aquatic life. Rain water is slightly acidic and many fresh water lagoons, swamps and reed beds are also acidic. Nevertheless, aquatic life flourishes in these wetlands.
- The oceans have a huge capacity resist being destabilised by changes in temperature or composition of the atmosphere. Whenever there is a change, the reactions of other chemicals or life in the sea act to moderate and even reverse those changes. Oceans cover about 71% of the Earth’s surface and the hydrosphere contains over 300 times the mass of gases in the atmosphere. The oceans thus have a huge capacity to buffer any variations in heat content or gas content emanating from the thin veil of atmospheric gases. The effect of man’s supposed 3% contribution to the tiny 0.039% of carbon dioxide in the Earth’s thin atmosphere would not register a long-term effect in the massive oceans.
- Cold ocean currents from the deep ocean periodically up-well to the surface. These currents are rich in dissolved carbon dioxide and other chemicals and decayed organic matter. Where this cold nutrient-rich water surfaces, there is a staggering profusion of aquatic life.
- Oceans have an unlimited ability to remove carbon dioxide from their waters and store it in thick beds of shells and corals, limestone, chalk, dolomite, magnesite, siderite, marls, methane hydrate and oil shales. Fresh water swamps and lakes on land have also laid down massive deposits of coal and lignite formed from carbon dioxide extracted from the atmosphere. Many of these deposits were laid down when the carbon dioxide content of the atmosphere was far higher than it is today.
- Carbon dioxide present in the oceans is essential to plant life and current very low levels of carbon dioxide in the atmosphere and the ocean are limiting plant growth. All animal life depends on these plants. Man’s mining and industrial activities are harmlessly recycling some of this valuable carbon dioxide from natural limestones and hydrocarbons buried in the dead lithosphere, back to the living biosphere.
- Corals are hardy and adaptable and have survived for 500 million years. During that time they have had to cope with warm eras, ice ages, extinction events, eras of massive volcanic activity, dramatic rising and lowering in sea levels and eons of time when levels of atmospheric carbon dioxide were far higher than today.
- A very recent extensive study of the Great Barrier Reef concluded that the changes forecast under the “business as usual greenhouse gas emissions” were unlikely to cause great harm to the reef.
- Any change in global temperature or the carbon dioxide content of the atmosphere will cause life on land and in the ocean to adjust and adapt. However, on balance, a warmer world with more plant food in the atmosphere and a more vigorous water cycle is very beneficial for the biosphere. The killer climates are associated with ice ages when the atmosphere is cold and dry, the sea levels are much lower and much of Earth’s fresh water is locked up in vast lifeless sheets of ice.
- There is no justification to use the baseless fear of “acidification of the oceans” as an excuse for a massive dislocation of our transport, food and energy industries. We should instead be focussing on real pollution problems (such as man’s rubbish floating in the oceans) and/or on preparing to cope with real and likely natural disasters (such as earthquakes, volcanic eruptions, tsunamis, floods, fires, cyclones and droughts).
To see a full report on “The Acid Ocean Bogey Man” by Viv Forbes with illustrations and explanations see: http://carbon-sense.com/wp-content/uploads/2012/05/acid-ocean-bogeyman.pdf [PDF, 1.2 MB]