A doubling of the amount of CO2 in the atmosphere could cause an increase in the average temperature on earth from 7 to even a maximum of 14 degrees.
A doubling of the amount of CO2 in the atmosphere could cause an increase in the average temperature on earth from 7 to even a maximum of 14 degrees. That is shown in the analysis of sediments from the Pacific Ocean off the coast of California, by researchers at NIOZ and the Universities of Utrecht and Bristol. The results were published in this week’s Nature Communications. “The temperature rise we found is much larger than the 2.3 to 4.5 degrees that the UN climate panel, IPCC, has been estimating so far”, said the first author, Caitlyn Witkowski.
45-year-old Drill Core
The researchers used a 45-year-old drill core extracted from the bottom of the Pacific Ocean. “I realized that this core is very attractive for researchers, because the ocean floor at that spot has had oxygen-free conditions for many millions of years,” said Professor Jaap Sinninghe Damsté, senior scientist at NIOZ and professor of organic geochemistry at Utrecht University. “As a result, organic matter is not broken down as quickly by microbes and more carbon is preserved,” Damsté said. He was also the supervisor of Witkowski, whose doctorate thesis included this research.
Unique Time Series
“CO2 over the past 15 million years has never before been examined from a single location,” Witkowski said. The upper thousand meters of the drill core correspond to the past 18 million years. From this record, the researchers were able to extract an indication of the past seawater temperature and an indiction of ancient atmospheric CO2 levels, using a new approach.
Read more at Royal Netherlands Institute for Sea Research
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