Pace of Ocean Acidification Has No Parallel in 300 Million Years
A new scientific paper suggests that the ocean is acidifying at a rate that is many times faster than at any time in the last 300 million years. The change is occurring so rapidly that it raises “the possibility that we are entering an unknown territory of marine ecosystem change,” said the paper, published this week in the journal Science…
Slow though they may have been, some of the past events caused profound planetary change. One of them, a stupendous series of volcanic eruptions in what is now Siberia starting about 250 million years ago, put so much carbon dioxide into the air over the course of a million years that it apparently wiped out most species on earth. Life took tens of millions of years to recover.
A more interesting analogy, however, may be the Paleocene-Eocene Thermal Maximum 55 million years ago, in which a pulse of carbon dioxide from an unknown source entered the atmosphere over several thousand years. That event produced immense environmental changes and some extinctions of life in the sea, but research suggests it did not lead to mass extinctions on land.
It did produce a rapid proliferation of new species as land animals adjusted to the environmental shifts. Our own lineage, the primates, apparently blossomed during that event, filling new ecological niches.
The new paper suggests that ocean acidification is now unfolding at at least 10 times the rate that it was during the Paleocene-Eocene Thermal Maximum. Thus, the scientists conclude that no past event is likely to serve as a perfect analogue for the human release of carbon dioxide, which “stands out as capable of driving a combination and magnitude of ocean geochemical changes potentially unparalleled” in 300 million years, the paper says.