To the editor:
I write in response to the Aug. 26 letter by Ron and Debbie Boggs. In their letter, they argue that the observed increases in carbon dioxide in the atmosphere have had only a minor effect on global climate. Their choice of years for comparison seriously distort the actual global climate record. Gordon Aubrecht, in his Sept. 3 letter, explains this well. Temperatures have already shown significant increases. What is most worrying to me are the projections for future climate disruption. If we continue to burn fossil fuels and pollute the atmosphere with unprecedented levels of CO2, the impacts will intensify.
What they have not mentioned is the direct influence of dissolved CO2 on the chemistry of our oceans. When CO2 dissolves in the oceans, it lowers the pH (acid-base balance). This change, called ocean acidification, is already having important effects. In response to rising temperatures and dropping pH levels, some coral reefs are showing decreased calcification, as well as bleaching, which threaten their continued existence.
Many planktonic (tiny floating) organisms in the oceans also possess calcareous skeletons susceptible to acidification. For example, the abundant floating snail-like organisms called pteropods are already suffering from shell thinning. If this continues, they may not be able to maintain their populations. Why should we care about microscopic plankton? These pteropods are a vital food source during certain stages in the life cycles of many important commercial fish that we eat including salmon, pollock, herring and cod.
Other studies have shown that ocean acidification will have a drastic impact on tiny forams (among the most abundant of all marine organisms). If conditions continue to change at current rates, the ocean chemistry will become fatal for these important components of the marine environment before the end of this century.
In the Antarctic Ocean, there have already been dramatic shifts. The primary food of many organisms, including the great whales, are krill. These tiny shrimp-like crustaceans have declined over ten-fold in many parts of the Antarctic since 1976. They are being replaced by a group called salps. These whispy jelly-like organisms are lower in nutrients and less suitable food for whales and others. These changes have the potential to upset the entire Antarctic food chain.
It shouldn’t surprise us that 150 years of rapid industrialization has had dramatic effects on the world we live in. If we choose to take a different, more sustainable, path, we can begin to restore our environment.