[Global Warming may be caused both naturally and by humans. –Bob]
By Rud Istvan – Re-Blogged From WUWT
WUWT reader KS of North Dakota emailed a request to ctm based on reading ‘alarming’ Wired journalism concerning $50 million being spent to further study the ‘dangerous’ Thwaites glacier in Antarctica. KS asked if WUWT could perhaps produce a factual overview. ctm asked me to provide it, since I had written an extensive essay ‘Tipping Points’ in ebook Blowing Smoke on this very sea level rise (SLR) subject (and more). What follows is a lightly rewritten and slightly expanded/updated excerpt for KS and the rest of WUWT.
There are only three ice sheets in the world with the potential to accelerate SLR to alarming levels: Greenland, the East Antarctic Ice Sheet (EAIS) and the West Antarctic Ice Sheet (WAIS).
In ‘theory’ Greenland could melt, since there is observed summer melting. It cannot calve (slide into) into the sea (although there are fringe glaciers like Jacobshaven that do, the Titanic sinking being evidence) because Greenland is bowl shaped. At the observed average annual ice mass loss of the past ~2.5 decades (from 1990) Greenland would theoretically take 27000 years to melt. At the ice mass loss rate since 2000, it would only take 14000 years and would increase SLR by a distinctly unalarming ~0.5mm/yr. In reality, given Greenland’s latitude and central ice sheet elevation, melting is impossible—as ice cores reaching back to the Eemian prove. Calculations and references behind this brief summary are provided in ‘Tipping Points’.