New predictions for sea level

Fossil coral data and temperature records from ice core measurements have been used to set more suitable limits for future sea level rise, and to test predictions about water levels. sea.

The results are published in Nature GeoScience and predict that by the end of the century, sea level rise will be between 7 to 82 cm - depending on global warming - this number is similar to predictions. of the IPCC report in 2007.

Setting limits on sea level rise in the next century is one of the biggest challenges for climate scientists . The uncertainty surrounding the various methods of making accurate predictions is often controversial because the reaction of the Greenland and Antarctic ice sheets to global warming is not well understood.

Dr. Mark Siddal of Bristol University, along with colleagues from Switzerland and the United States, used fossil coral data and recorded temperatures from the ice measurement to reconstruct ink fluctuations. seawater in response to climate changes over the past 22,000 years , a period covered the transition from the coldest ice to the warm Holocene period.

By examining the sea level's response to the temperature from the most recent glacial period, Siddall and colleagues predicted that the rise in sea level by the end of the century would be similar to what the Report made by the Intergovernmental Panel on Climate Change (IPCC).

What will the sea level be like? (Photo: rixane.com)

Dr. Siddall said: 'Two completely readable methods have yielded the same results that further increase the reliability of this study. The fact that these results, based on rich data on fossil corals, are very close to what IPCC estimates are very important. '

'In addition, the fixed time of sea level response is 2,900 years, our model shows that the impact of this 21st century warming will continue for centuries to come. Therefore, it will form a very important part of future climate change. '

IPCC used complex climate models to perform their analysis, while Siddall and colleagues used only simple and basic models.

The new model explains the observed variation in the last 22,000 years, and with the minimum predicted warming temperature (1.1 degrees Celsius) and the maximum (6.4 degrees Celsius) of the IPCC model and model. This predicts that the sea level will rise by 7 to 82 cm by the end of the century.The IPCC model predicts narrower sea levels - between 18 and 76 cm.

Researchers stress that because we will live in a turbulent climate for at least 200 years at the end of this century, so lessons of long-term changes in the past may be the key to understand future changes.

Sponsorship: Mark Siddall recognizes help from Lamont Doherty Earth Observatory, where part of the research is done, and the University of Bristol. Assistance from the Swiss National Science Foundation and the University of Bern (Thomas F. Stocker) and the United States National Scholarship Fund (Peter U. Clark) were also recorded.

Refer:
1. Mark Siddall, Thomas F. Stocker and Peter U. Clark.Constraints on future sea level rise from past sea-level reconstructions.Nature Geoscience, DOI: 10.1038 / NGEO587