There’s more this week on the critical but in some ways under-covered issue of ocean acidification.
At root, it’s simple chemistry. Carbon dioxide goes into the air from factory chimneys and hearths and car exhaust pipes, and some of it ends up dissolved in seawater, as carbonic acid.
As carbon dioxide in the atmosphere now tops 380 parts per million (ppm), whereas the past few million years have seen oscillations between about 180 and 280ppm, it’s hardly a surprise that seawater is now more acid than during this recent period of Earth history.
It’s been much higher in previous ages; but as always, it’s not just the scale of the change that’s important, but the speed.
A new study in Nature Climate Change journal [released to journalists but not apparently on the journal website as yet] has tried to measure the current rate of change against what happened in pre-industrial times.
It’s reliant on computer models to provide historical estimates; but with that caveat, the numbers are startling, suggesting that the current rate of acidification is two orders of magnitude bigger than what happened at the end of the last Ice Age.
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Richard Black, BBC News, 23 January 2012. Full article.
