Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
kennethrichards comment

Quote:According to the IPCC (2013), sea levels rose at a rate of 1.7 mm/year (6.7 inches per century) for the 1901 to 2010 period, but 3.2 mm/year (12.6 inches per century) during the 18-year period between 1993 to 2010, a rate similar to that obtained from 1920 to 1950.
“It is very likely that the global mean rate was 1.7 mm yr–1 between 1901 and 2010 for a total sea level rise of 0.19 m. Between 1993 and 2010, the rate was very likely higher at 3.2 mm yr–1; similarly high rates likely occurred between 1920 and 1950.”

Problematically, in recent decades the source contribution estimates for recent decades from published studies add up to half (or less) of this claimed rate for 1993 to 2010.
According to recent estimates, the contribution to sea level rise from thermal expansion was 0.64 mm/yr (2.5 inches per century) for the period between 2005-2013 (Llovel et al., 2014, see below). The contribution from the Greenland (GIS) and Antarctic (AIS) ice sheets was 0.59 mm/yr (2.3 inches per century) for the 1992-2011 period (Shepherd et al., 2012). The contribution from global glaciers and ice caps that are not the GIS or AIS was 0.41 mm/yr (1.6 inches per century) for 2003-2010 (Jacob et al., 2012).

Llovel et al., 2014
Over the entire water column, independent estimates of ocean warming yield a contribution of 0.77 ± 0.28 mm yr−1 in sea-level rise … the deep ocean (below 2,000 m) contributes −0.13 ± 0.72 mm yr−1 to global sea-level rise [0.64 mm/yr total].

Shepherd et al., 2012
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.

Jacob et al., 2012
Here we show that GICs [glaciers and ice caps], excluding the Greenland and Antarctic peripheral GICs, lost mass at a rate of 148 ± 30 Gt yr−1 from January 2003 to December 2010, contributing 0.41 ± 0.08 mm yr−1 to sea level rise.

These sources add up to about 1.6 mm/year, which is the equivalent of a little over 6 inches per century. Interestingly, this is the same or slightly less than the rate for the entire 1901 to 2010 period (1.7 mm/year, IPCC), meaning that sea level rise has not accelerated in recent decades according to the summation of source estimates.
Additionally, if we include the Zwally et al., 2015 paper, which indicated that net gains for Antarctica negatively contributed to sea level by -0.28 mm/year between 1992-2008, sea level rise contributions drop down to 1.3 mm/year, or 5 inches per century in recent years.
It is our attitude toward free thought and free expression that will determine our fate. There must be no limit on the range of temperate discussion, no limits on thought. No subject must be taboo. No censor must preside at our assemblies.

–William O. Douglas, U.S. Supreme Court Justice, 1952

Users browsing this thread: 1 Guest(s)