This epoch’s paper-plate award for “global warming’s ‘equally evil twin'” (120) goes to… ocean acidification! Like global warming really needs an evil twin. And I highly anticipate that there we have yet to meet the rest of the family. As global warming progresses, ecosystems will start to reshape and eventually collapse in ways unimaginable right now. I must admit, I don’t sound altogether enthused but it is fairly hard to write an upbeat blog on a book called The Sixth Extinction.
The most recent chapters of Kolbert’s book have focused on our planet’s wonderful but declining oceans. First, she took me to the Mediterranean where an underwater vent spewing a constant stream of carbon dioxide bubbles has acidified the water and created a microcosm of water from the future. There researchers have been able to peer into the water of oceans to come, and in varying degree too, because as distance from the vent increases, so does pH! The moral of the story learned from the vents is that acidified water is very unfavorable for sea life, as so many organisms, both micro and macroscopic, depend upon calcification to create their shells and exoskeletons. And when you remove even one link of the food chain, the rest is fairly messed up.
After watching bubbles in the Mediterranean, Kolbert took us to the Great Barrier Reef, one of the most magnificent and diverse ecosystems on earth, the ocean equivalent of the tropical rainforests. As atmospheric carbon dioxide increases and the ocean subsequently acidifies, the delicate symbiosis that every coral depends on is messed up. Coral is actually two groups of animals coexisting: coral polyps and zooxanthellae. As the ocean increases in acidity, the zooxanthellae begin to produce dangerous radicals, leaving their neighbors no option but to evict them. Without the zooxanthellae, the polyps lose their color – hence the term “bleaching” – and the polyps cease to grow and reproduce, and eventually starve and die. Kolbert also makes it clear that many coral reefs may not even last long enough for acidification to get to them. The rest of the threats are much more directly anthropogenic: overfishing, deforestation and pollution, and more.
Again, I cannot stress enough that this situation mandates action not despair. Kolbert does an admirable job (far better than I have done) of presenting the evidence in a pragmatic way. I encourage you to read the book yourself. Clearly the book is not disheartening enough to make me put it down forever.
To end on a more magical note, Kolbert describes snorkeling at night during coral spawning like swimming in “a blizzard in the Alps, only in reverse” (147). Let the moments like these remind us what were fighting to preserve and what is at stake if we fail, and as Apollo 13 reminds us “failure is not an option.”