New research which reveals details on changes in the Earth’s climate from more than 100,000 years ago – will be published online (Thursday, January 24, 2013) in leading journal Nature, by a team which includes Swansea University scientist, Professor Siwan Davies.
This new study provides surprising details on changes in the Earth’s climate and indicates that the last interglacial period may be a good analogue for where the planet is heading in the face of increasing greenhouse gases and warming temperatures.
Prof Davies, accompanied an international team of researchers from 14 countries to North Greenland to analyze ice from the last ‘warm period’ on Earth, known as the Eemian period.
Led by the Centre for Ice and Climate at the University of Copenhagen, the team drilled more than 2.5 km to bedrock between 2008 and 2012 as part of the North Greenland Eemian Ice Drilling project (NEEM).
The new findings reveal that the climate in North Greenland between 130,000 and 115,000 years ago was 8 degrees Celsius warmer than today and the seas were roughly four to eight meters higher. Intense surface melting was especially noted during the early stages of the last interglacial.
But the research also shows that the ice-sheet surface in this area was only a few hundred metres lower than present suggesting that the Greenland ice-sheet contributed less than half of the total sea-level rise at this time. This then suggests that the more unstable West Antarctic ice-sheet must be responsible for a significant part of the 4-8m rise in sea level during this period.
The intense surface melt during the warm Eemian period was seen in the ice core as layers of re-frozen meltwater. Such melt events during the past 5,000 years are very rare by comparison, confirming that the surface temperatures in Greenland during the Eemian were significantly warmer than today. A rare modern melt event was observed during the field campaign in July 2012, and whilst this was an extreme event, future warming may lead to enhanced surface melting in Greenland.
Professor Siwan Davies from the University’s Department of Geography said: ‘‘For the first time, a detailed record of climate changes during the last interglacial has been achieved from a deep ice-core in Greenland and this study shows the importance of investigating this period to see how our planet will respond in a warmer world.’’
Prof Davies’ research focuses on volcanic ash particles within the ice which enables them to date the climatic events chronicled in the ice and reconstruct the history and frequency of volcanic eruptions in the past. Her research is funded by the European Research Council and the Natural Environment Research Council (NERC).
To view the paper, “Eemian interglacial reconstructed from a Greenland folded ice core’’ visit http://www.nature.com/nature/journal/v493/n7433/full/nature11789.html
Picture: Professor Siwan Davies examining the ice core
- Thursday 24 January 2013 10.22 GMT
- Thursday 24 January 2013 10.18 GMT
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