Guest author and analyzer of climate science literature Kenneth Richard presents an essay on sea level rise and James Hansen’s latest alarmist paper.
Mt. Herschel Antarctica. Photo by Andrew Mandemaker, CC BY-SA 2.5
Only science deniers don’t believe in catastrophe
By Kenneth Richard
Now that the latest James Hansen catastrophic sea level rise paper (Hansen et al., 2016) has been affirmed by peer review, it has, according to Slate‘s meteorologist Eric Holthaus, been effectively “canonized.” In other words, it has become scientifically authoritative.
James Hansen’s Bombshell Warning Is Now Part of the Scientific Canon”
The paper, which has undergone some wording revisions since the original version appeared last July (so that it could be accepted for publication), apparently “concludes” that the polar ice sheets will soon melt catastrophically; this ice sheet melt contribution will in turn result in sea level rise of “at least 10 feet in as little as 50 years” according to a summation from the same Eric Holthaus:
The study—written by James Hansen, NASA’s former lead climate scientist, and 16 co-authors, many of whom are considered among the top in their fields—concludes that glaciers in Greenland and Antarctica will melt 10 times faster than previous consensus estimates, resulting in sea level rise of at least 10 feet in as little as 50 years.
Putting aside for the moment that (a) Greenland’s vast interior ice sheet has been melting more slowly in recent decades than it has for 95% of the last 9,000 years (MacGregor et al., 2016), or that (b) the West Antarctic Peninsula melted faster during the Medieval Warm Period than it has in recent decades (Guglielmin et al., 2016), or that (c) the northern Antarcitc Peninsula melted 10 times more slowly between 2003-2014 than it did between 1995 and 2003 (Seehaus et al., 2015)…
Or, putting aside that (d) the rate of sea level rise contribution from the Antarctic and Greenland ice sheets combined was just 2.3 inches per century (0.59 mm/year) between 1992 and 2011 (Shepherd et al., 2012).
Alas, with inconveniences put aside, Hansen’s claim of 10 feet of sea level rise in 50 years has nonetheless been officially anointed as scientifically authoritative anyway. Therefore, to deny the conclusions of Hansen’s paper is tantamount to denying climate science. After all, that’s what science deniers do. They deny canonized climate science like Hansen’s sea level rise forecasts.
To avoid being characterized as a science denier, one effectively must believe that the sea level rise contribution from the Antarctic and Greenland ice sheets combined will catapult from the current rate of 0.23 of an inch per decade (Shepherd et al., 2012) to 10, 50, or perhaps 100 times that rate so as to reach 24 inches per decade total sea level rise through the mid-2060s (so that Hansen’s sea level rise estimate of “at least 10 feet in as little as 50 years” can be realized).
Don’t agree that one should be categorized as a science denier if she or he doesn’t agree with Hansen’s catastrophic melt and sea level rise forecasts? Well, that immediately begs the question: How many meters (or feet) of sea level rise must one believe in to avoid being labeled a science denier? If one believes in only 2 meters (~7 feet) of sea level rise by 2100, for example, is that denying canonized climate science?
The IPCC’s last two reports (2007, 2013) confer sea level rise forecasts ranging from a low threshold of 18 cm to a high threshold of 98 cm (between 7 and 39 inches) by 2100. One would assume, then, that with the scientific canonization of Hansen’s latest paper, the low range IPCC estimates are now effectively in the science denier camp. If not science denier, how else does one categorize a forecast of just 7 or 10 or 12 inches of sea level rise by 2100?
Specifics are needed here. After all, no one wants to be called a science denier due to non-belief in authoritative climate science. So again, how much sea level rise by 2100 must one minimally believe in to avoid being called a science denier now that Hansen’s sea level rise catastrophe paper has been canonized?
Recent peripheral thinning of the Greenland Ice Sheet is partly offset by interior thickening and is overprinted on its poorly constrained Holocene evolution. On the basis of the ice sheet’s radiostratigraphy, ice flow in its interior is slower now than the average speed over the past nine millennia.”
[T]he interior of the GrIS is flowing 95% slower now than it was on average during the Holocene.”
Based on new radiocarbon dates, during the MWP [Medieval Warm Period], the rate of glacier retreat [West Antarctic Peninsula] was 1.6 m yr−1, which is comparable with recently observed rates (~0.6 m yr−1 between 1993 and 2011 and 1.4 m yr−1 between 2005 and 2011).”
Highlights: Ice mass loss (2003–2014) was approximately one order of magnitude smaller than between 1995–2003.
“The northern Antarctic Peninsula is one of the fastest changing regions on Earth. The disintegration of the Larsen-A Ice Shelf in 1995 caused tributary glaciers to adjust by speeding up, surface lowering, and overall increased ice-mass discharge. … The contribution to sea level rise was estimated to be 18.8±1.8 Gt, corresponding to a 0.052 ± 0.005 mm sea level equivalent for the period 1995–2014.”
Since 1992, the polar ice sheets [Antarctica and Greenland] have contributed, on average, 0.59 ± 0.20 millimeter year−1 to the rate of global sea-level rise.”