Global climate change or global warming has many facets. The earth's rising temperatures are causing the polar ice caps to melt along with mountain glaciers, resulting in sea-level rise. There is an increase in violent weather patterns where parts of the planet experience extreme drought while others experience massive flooding and severe storms. Ocean acidification, sometimes referred to as the other CO2 problem, has the potential to alter the fragile ocean eco-system through species depletion and habitat destruction and, in doing so, bring unintended consequences to mankind.
Today the world's oceans have absorbed nearly 30% of all the CO2 emitted into the atmosphere since the beginning of the industrial revolution. The oceans act as a carbon sink, and this process "has a direct and measurable impact on ocean chemistry" (Logan 819). As the oceans absorb CO2 it dissolves into seawater creating carbonic acid, which further breaks down into bicarbonate, carbonate and hydrogen ions. This change in the oceans chemistry has caused the oceans pH to drop from 8.2 to 8.1. "Because pH is measured on a logarithmic scale"this change is roughly equivalent to a 30% increase in the concentration of hydrogen ions" (Logan 819).
As the ocean has already had a drop in the pH of .1 units, and human activities continue to escalate, the pH is predicted to fall by .5 units by 2100. What effects will this have on the ocean's eco-system?
The effects of ocean acidification, even under low predictions for future CO2 emissions, could make tropical and sub-tropical reefs all but nonexistent by 2050. This would have devastating consequences for species of fish that live and breed on the reef structure. It will also affect the people who live near the reefs as they rely on them for food and protection against storms and floods (Papasian 8).
Carbonic acid is corrosive to the shells of marine organisms. Sea creatures such as corals, shellfish, sea urchins, and starfish are most likely to experience the effects of ocean acidification because the acid makes it difficult for them to form and maintain their calcium-carbonate skeletons and shells. Scientists also warn that the acidity could adversely affect phytoplankton and zooplankton, some calcifying organisms that are very important to the base of Earth's food chain (Papasian 8).
Phytoplankton form the base of the ocean food chain and need calcium to build their shells to protect them from predators. The inability of phytoplankton to "build their shells could have a ripple effect throughout the marine food web. It's going to change the dominant organism in the food chain, and there's a very real danger that it may short-circuit the food chains. In other words, ciliate protozoa gorging on unprotected phytoplankton may flourish at the expense of other organisms higher up the food chain" (US Fed News 2008).
What does all this mean for mankind? Speaking from the Brisbane Writers Festival, Allana Mitchell and Dr. Charlie Vernon spoke of a grim future for the planet's oceans. Ms. Mitchell stated that, "If everything on land were to die tomorrow, the ocean wouldn't even notice, but if everything in the ocean were to die tomorrow, everything on land would also die" (APP 2008). Dr. Veron stated that ocean acidification will lead to "mass extinctions once CO2 levels reach a tipping point and began driving themselves" (APP 2008). Some scientists think that point to be 560ppm CO2 in the atmosphere. This automatic-feedback loop is uncontrollable and moves towards mass extinction. "By 2050 ocean acidification will have taken hold", stated Dr. Veron. Ms. Mitchell stated that "We could face the fifth mass extinction on the planet, the last one being 65 million years ago". Dr. Veron added "Mass extinctions are horrific beyond imagination" (APP 2008).
Today the atmosphere is at an all-time high of 400ppm CO2. Without significant reductions in greenhouse-gas emissions the world faces an uncertain future. There are many skeptics who claim global climate change to be a hoax; however, you cannot argue against basic physics and chemistry. The world is expanding at a rapid rate; countries like China and India are in their own industrial revolutions. In less than 35 years the earth may approach an automatic-feedback loop, which would be uncontrollable and devastate much of the eco-systems, sending the earth towards mass species extinction. As go the oceans, so go the species that inhabit the earth.
AAP General News Wire "Qld: Grim Outlook for the Oceans" Wire Sydney 21 Sep 2008
ProQuest 21 May 2013
Logan, Cheryl. "A Review of Ocean Acidification and America's Response" Journal of Bioscience 60 10 (Nov 2010) 819-828 EBSCO 21 May 2013
Papasian, Melanie. "pH Unbalanced" Journal of Environment 47 8 (Oct 2005) 8 ProQuest 21 May 2013
US Fed News Service "Ocean Acidification Could Have Broad Effects on Marine Ecosystems" Newspaper Washington D.C. 17 Dec 2008 ProQuest 21 May 2013