ANCIENT CLIMATE CHANGE ‘LINK’ TO CO2
Baku, June 18 (AZERTAC). A “global pattern” of change in the Earth`s climate began 2.7 million years ago, say scientists.
Researchers found that, at this point, temperature patterns in the tropics slipped into step with patterns of Ice Ages in the Northern Hemisphere.
They report in the journal Science that atmospheric CO2 could be the “missing link” to explain this global pattern.
The findings, they say, reveal a “feedback process” that could have been magnified by greenhouse gases.
This loop of feedback could have intensified both the Ice Ages in the Northern Hemisphere, and temperature fluctuations in the tropics.
Professor Timothy Herbert from Brown University in Rhode Island, US, led the research.
He and his colleagues, in the US and China, analysed mud cores from the seabed in the four tropical ocean basins - the Arabian Sea, the South China Sea, the eastern Pacific and the equatorial Atlantic Ocean.
These mud cores are laid down over millions of years - as sediments of dead plant and animal material sink to the ocean floor.
So by analysing the chemical composition of this material - specifically the chemical remains of one ancient and tiny marine organism - the scientists were able to produce a timeline of temperature changes.
The team “found a fingerprint in the sequence of temperature changes” - a pattern that began 2.7 million years ago, Professor Herbert explained.
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