Mineral spikes in sea-floor sediments coincide with halt in temperature rise
Z. Ma et al/Nature Geoscience 2014
Ocean-dwelling bacteria may have vacuumed up carbon and halted a period of extreme warmth some 56 million years ago, according to a study published April 13 in Nature Geoscience.
The finding suggests how Earth might once have rapidly reversed a runaway greenhouse effect. However, rapidity is relative: The bacteria would be far too slow to head off today’s human-caused climate impacts.
Scientists seeking to understand the present-day climate often study the Paleocene-Eocene Thermal Maximum, a hot period that occurred around 55.9 million years ago. During this roughly 170,000-year period, atmospheric carbon dioxide levels soared, temperatures rose by 5 degrees Celsius or more and ocean acidity spiked. The period ended in a hurry, geologically speaking, over the course of 30,000 to 40,000 years. Scientists are unsure what stopped the warming; possibilities include uptake of carbon by organisms or by rock.