Researchers using sophisticated research vessels
extract deep-sea sediment cores from oceans
around the world to chart past climate change.
Credit: UCB
Here’s one climate nightmare: Melting permafrost releases vast quantities of methane into the air, triggering a runaway greenhouse effect that accelerates global warming.
Or how about this? A shift in ocean currents and deep-water temperatures suddenly frees billions of tons of carbon dioxide. It essentially fizzes into the sea and gives the Earth’s atmosphere a greenhouse jolt that makes recent warming seem chilly.
This is not some bad science fiction plot summary. Climate scientists at the University of Colorado Boulder have found evidence of two colossal global-wrenching “burps” that earped up from the deepest ocean near the end of the last ice age.
In Marine Radiocarbon Evidence for the Mechanism of Deglacial Atmospheric CO2 Rise, published this week in the online edition of Science, the Colorado team traced the origin of the 600 billion tons of carbon suddenly released into the air about 18,000 and 13,000 years ago.
That’s twice as much carbon dioxide as what humans have managed to produce through burning fossil fuels over the past few centuries.