The period of surface temperature rise on Earth that occurred 55 million years ago is the main cause of changes in ocean currents. This is the conclusion reached by American researchers.
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Ocean currents changed as Earth’s temperature rose |
Scientists from the Scripps Institution of Oceanography at the University of California, after measuring carbon-13 isotopes in samples taken from 14 sites across all four oceans, discovered that 55 million years ago, the surface temperature of the Earth increased by 5 to 8 degrees Celsius in a very short period, disrupting the deep ocean currents.
The entire system of these currents only traveled halfway before reversing direction.
Before the rise in Earth’s temperature, the deep ocean currents turned around in the Southern Hemisphere, but for the next 40,000 years, as the temperature continued to rise, these currents did not reach the Southern Hemisphere and instead turned back in the Northern Hemisphere.
It took nearly 100,000 years for them to resume normal circulation.
The cause of Earth’s warming during this period remains unclear. Among the hypotheses proposed, scientists are particularly noting the evidence of numerous volcanic eruptions that released trillions of tons of carbon dioxide (CO2).
This discovery is particularly significant; although it occurred tens of millions of years ago, its lessons are still relevant today. Scientists have another piece of evidence showing that humanity will continue to suffer severe consequences from the reckless release of CO2 into the atmosphere due to the use of fossil fuels.
This study reinforces a previous finding published in November 2005, which indicated that global warming is slowing the flow of the Gulf Stream in the Atlantic Ocean, a current that historically has provided Western Europe with a milder climate.
According to the latest data from the United Nations climate assessment group, the Earth’s surface temperature could increase by 1.4 to 5.8 degrees Celsius by 2100 compared to 1990 levels.
