Those of you who read this blog know that I often post on issues related to global warming and the environment. In general, I think most environmental scientists have a pretty pessimistic view of the state of things to come and the challenges we’re going to be facing over the next 50 years, largely due to the magnitude and variety of impacts related to global warming, along with many unrelated issues.
One of the scary things that hasn’t really gotten into the public consciousness yet is the acidification of the oceans. The CO2 we’re adding into the atmosphere is counterbalanced somewhat by the ocean, which acts as a giant reservoir into which some of the CO2 can dissolve. Unfortunately, when it does so, the oceans become more acidic. The amount of CO2 that has been added to the oceans has already started to tip the balance, and there are measurable changes in pH. This process also reduces carbonate in seawater, which makes up coral reefs and the exoskeletons of small organisms important at the base of the oceanic food chain.
I know you’re still waiting for the ray of hope, so here it is. There’s a fascinating short article in Science (Mar 30 2007) which describes an experiment in which a variety of corals were exposed to more acidic ocean water, to see what would happen. The fossil record suggests that corals have survived periods of global warming in past geologic history, but no-one was quite sure how. It turns out that in fact the corals do lose their skeletons, and the little critters inside have their soft bodies exposed.
Astonishingly, they can live that way. They seem to grow and thrive perfectly well, as long as they are attached to a hard rock that doesn’t dissolve. We would still lose the coral reefs and all the structural diversity they provide, but the living beings in the coral would survive. And the research showed that once things get back to normal again – the critters build their little exoskeletons and the coral rebuilds itself. !!
I for one found this pretty amazing. Of course there are still 900 other things that can and will go wrong, but it’s just such a relentless tide of bad news that it’s wonderful to see one little part of the ecosystem that can adapt.