The good news for the climate is that the oceans can absorb an enormous amount of carbon dioxide, a huge buffer against global warming. The bad news is for the oceans. When sea water absorbs CO2 it has the nasty habit of turning some of it into acid. This has been going on for decades and warnings about the effects of ocean acidification have been going up nearly as long. Add this most recent warning from one hundred of the top marine biologists in Europe: The oceans have become 30% more acid since the dawn of the industrial age, and are now more acid than any time in the last 55 million years.
It’s not hard to imagine that acid seawater may cause problems. Unfortunately, the problems are more widespread, subtle, and cumulatively damaging than expected. The various ecosystems of sea creatures have adapted over many thousands of years to certain levels of acidity. Now the acidity is changing almost by the decade; there is no time for adequate adaptation. Delicately balanced marine ecosystems are falling apart, coral reefs being one example. The new report documents several other effects to illustrate how subtle some of the ramifications can be:
• whales and dolphins, who will find it harder to navigate and communicate as the seas become “noisier”. Sound travels further as acidity increases. Noise from drilling, naval sonar and boat engines is already travelling up to 10% further under water and could travel up to 70% further by 2050.
• brittle stars (Ophiothrix fragilis) produce fewer larvae because they need to expend more energy maintaining their skeletons in more acid seas. These larvae are a key food source for herring.
• tiny algae such as Calcidiscus leptoporus which form the basis of the marine food chain for fish such as salmon may be unable to survive.
• young clownfish will lose their ability to “smell” the anemone species that they shelter in. Experiments show that acidification interferes with the species’ ability to detect the chemicals that give “olfactory cues”.
[Source: The Guardian]
Of course, the acidification of the seas is intimately related to global warming; any approach to improving conditions for the climate will simultaneously affect the oceans. The main problem is time. Global systems, particularly those in massive bodies of water, do not ‘turn around’ quickly. As the report points out (it was prepared with the Copenhagen Climate Conference in mind), it will take concerted and significant control of CO2 emissions. That this report – the work of 26 different research institutions – must compete against the noise of “ClimateGate” about a handful of scientists at one institution at a conference that must soberly digest the political and scientific realities…