How Fossil Corals Can Shed Light On The Earth’s Past Climate

2015-09-28T15:36:32+00:00 September 29, 2015|
 Reef fish called Chromis viridis (blue-green chromis) and Chromis margaritifer (bicolor chromis) swim among the staghorn coral (Acropora acuminata) at Palmyra Atoll National Wildlife Refuge in the Pacific. (Credit: Amanda Meyer/USFWS)

(Click to enlarge) Reef fish called Chromis viridis (blue-green chromis) and Chromis margaritifer (bicolor chromis) swim among the staghorn coral (Acropora acuminata) at Palmyra Atoll National Wildlife Refuge in the Pacific. (Credit: Amanda Meyer/USFWS)

In a paper published today in Science, researchers from the University of Bristol describe how they used radiocarbon measured in deep-sea fossil corals to shed light on carbon dioxide (CO2) levels during the Earth’s last deglaciation.

(From Phys.org) — Around 18,000-11,000 years ago, the Earth’s climate system experienced a dramatic shift: a period known to paleoclimate scientists as the last deglaciation. During this period, atmospheric CO2 concentration increased by ~80 parts per million (ppm), accompanied by sea level rise of almost 120 metres due to ice sheet melting and global warming.

Recent high-resolution ice core CO2 records have revealed that there were three abrupt centennial-scale atmospheric CO2 increases of ~10 ppm superimposed on the more gradual millennial-scale deglacial CO2 rise. The second and third of these events also coincided with abrupt warming of the high latitude North Atlantic region.

The rate of Atlantic Meridional Overturning Circulation – that is, the formation in the high latitudes and associated upwelling – is closely related to the temperature of the North Atlantic region and thus might also be related to these CO2 releasing events. However it has been remarkably hard to find marine archives that can show how deep oceans behave on rapid timescales.

Read the full article here: http://phys.org/news/2015-09-fossil-corals-earth-climate.html