This post is from a great science blog whose motto is:
Getting Skeptical about Global Warming Skepticism
Posted on 30 January 2013
A paper recently published in Global Environmental Change by Brysse et al. (2012) examined a number of past predictions made by climate scientists, and found that that they have tended to be too conservative in their projections of the impacts of climate change. The authors thus suggest that climate scientists are biased toward overly cautious estimates, erring on the side of less rather than more alarming predictions, which they call “erring on the side of least drama” (ESLD).
In this paper, Brysse et al. examined research evaluating past climate projections, and considered the pressures which might cause climate scientists to ESLD.
Conservative Climate Projections
While we have recently shown that the Intergovernmental Panel on Climate Change (IPCC) temperature projections have been exceptionally accurate, several other projections in the IPCC reports have been far too conservative.
Sea Level Rise
For example, Rahmstorf (2007) and more recently Rahmstorf et al. (2012) showed that sea level is rising at a rate inconsistent with all but the highest IPCC scenarios (Figure 1). Rahmstorf et al. (2012) concluded,
“The satellite-based linear trend 1993–2011 is 3.2 ± 0.5 mm yr-1, which is 60% faster than the best IPCC estimate of 2.0 mm yr-1 for the same interval”
Figure 1: Sea level measured by satellite altimeter (red with linear trend line; AVISO data from (Centre National d’Etudes Spatiales) and reconstructed from tide gauges (orange, monthly data from Church and White (2011)). Tide gauge data were aligned to give the same mean during 1993–2010 as the altimeter data. The scenarios of the IPCC are again shown in blue (third assessment) and green (fourth assessment); the former have been published starting in the year 1990 and the latter from 2000.