January 14, 2015

expert reaction to new research on sea level rise

A paper published in the journal Nature has estimated the degree to which sea levels rose in the twentieth century. The researchers report increases in sea levels which are in line with previous estimates for the period of 1993-2010, but which are higher than previous estimates for the period of 1901-1990.

Prof. Jonathan Gregory, Climate Modeller at the University of Reading, said:

“The IPCC report of 2013 gave a range of 1.3-1.7 mm yr-1 for global mean sea level rise during 1901-1990. The new estimate of Hay et al. of 1.0-1.4 mm yr-1 is somewhat smaller, but overlaps the IPCC range.  They have taken a useful step forward in including information about the effect of land ice changes on the geographical pattern of sea level change in order to obtain their result.

“Although they arrive at a slightly lower sea level rise over the 20th century, they also find that sea-level rise has accelerated in recent years.  Since future sea level rise is a serious concern, it would be useful to have more information on the comparison of their estimates of the contributions to global mean sea level rise (thermal expansion, glaciers, ice sheets) with other published estimates, because we need to understand the contributions in order to be able to assess the implications for projections.”

‘Probabilistic reanalysis of twentieth-century sea-level rise’ by Carling C. Hay et al. published in Nature on Wednesday 14 January.

Declared interests

None declared