Scientists from the University of Bristol (UK) are for the first time using a new approach that carefully solicits and pools expert judgements to determine future sea level rise due to the melting of the Greenland and Antarctic ice sheets.
This new approach is already used in volcanic eruption forecasting and the prediction of vector borne diseases.
Summit Observatory (10,500 FT above sea level), Greenland Ice Sheet. Image courtesy of NOAA.
Co-author of the study Professor Jonathan Bamber said: "This is the first study of its kind on ice sheet melting to use a formalized mathematical pooling of experts' opinions. It demonstrates the value and potential of this approach for a wide range of similar problems in climate change research, where past data and current numerical modelling have significant limitations when it comes to forecasting future trends and patterns." (via University of Bristol)
The research team of Bamber and Professor Willy Aspinall determined that the median estimate for sea level rise due to ice sheet melting alone was 29 cm (~about a foot) by 2100.
When they combined the above result with other sources of sea level rise they found a conceivable risk of a rise of greater than one meter (100 cm) by 2100. On the other hand, the most recent IPCC range estimate for sea level rise by 2100 was anywhere from 18 cm to 59 cm for six possible scenarios.
Of note, the University of Bristol press release reports that the researchers also found that the scientists, as a group, were highly uncertain about the cause of the recent increase in ice sheet mass loss observed by satellites and equally unsure whether this was part of a long term trend or due to short-term fluctuations in the climate system.
NBC News Science just posted about this same study and quoted the author as saying that the consequences are horrible.
A particular climate geoengineering effort to reduce the amount of sunlight might not work out.....
Understanding the climate model.
A look at the model projected long-term changes in global temperatures and precipitation based on a combination of four greenhouse gas emission scenarios.
Going back 10,000 years, researchers have determined that the Greenland Ice Sheet was actually at its smallest size between three and five thousand years ago.
Observed changes in global precipitation are directly affected by human activities and cannot be explained by natural variability alone.
Better late than never. Here is the global October 2013 satellite measured temperature anomaly data