When we last caught up with Richard Zeebe, a professor at the University of Hawaii at Manoa’s School of Ocean and Earth Science and Technology, he told us his research indicated that climate change’s effects would happen faster and to a greater degree than most people realized (see “University of Hawaii Professor Richard Zeebe says climate change will be more severe than scientists originally thought,” Aug. 15, 2013). But on Mar. 21, UH sent out a press release on a new study co-authored by Zeebe in the journal Nature Geoscience is even scarier.
“Their findings suggest humans are releasing carbon about 10 times faster than during any event in the past 66 million years,” states the news release.
Zeebe and his fellow researchers were able to “determine the duration of the onset of an important past climate event, the Paleocene-Eocene Thermal Maximum, PETM for short, 56 million years ago,” according to the news release. This allowed them to make a startling finding.
“The rate of carbon release during the PETM was determined to be much smaller than the current input of carbon to the atmosphere from human activities,” stated the news release. “Carbon release rates from human sources reached a record high in 2014 of about 37 billion metric tons of CO2. The researchers estimated the maximum sustained carbon release rate during the PETM had to be less than 4 billion metric tons of CO2 per year–about one-tenth the current rate.”
This means the climate change researchers are observing now is potentially the worst such event in the last 66 million years.
“Everyone is focused on what happens by 2100,” Zeebe said in the news release. “But that’s only two generations from today. It’s like: If the world ends in 2100 we’re probably OK! But it’s very clear that over a longer timescale there will be much bigger changes.”
How big is he talking about? Here’s the last line of the journal article’s abstract, which should give you some idea: “Also, future ecosystem disruptions are likely to exceed the relatively limited extinctions observed at the PETM.”
Click here for the full text of the new UH news release.
Photo of deep-sea sediment cores (the red band marks the onset of the PETM): J. Zachos