First posted Dec. 8, 2011 on the Earth Institute’s State of the Planet blog.
Oceans turned more acidic during a period of great warming some 56 million years ago, leading to an extinction of bottom-dwelling marine species known as foraminifera, a scenario that could be repeated as a result of human-induced global warming today, only much more quickly.
To better understand what could happen in the near future, geochemist Bärbel Hönisch of the Lamont-Doherty Earth Observatory and a few colleagues studied ocean acidity events over the past 250 million years to confirm whether acidification took place during periods of global warming. The conditions of one period in particular – the Paleocene-Eocene Thermal Maximum — were similar to the worst-case scenarios scientists project for future climate change.
“The earlier changes affected the biology, so we’d expect that would happen today,” Hönisch said. She doesn’t like to speculate on precisely what the impact might be; some creatures may disappear, others may adapt.
“I don’t think it will destroy the earth — the earth will cope with us,” she said. “We may not like what happens.” Hönisch gave a talk on her research today at the fall meeting of the American Geophysical Union in San Francisco, as part of a broader discussion there of findings related to ocean acidification.