Why do we expect glacier melting to increase under global warming?

• Main Author: Braithwaite, R. J.
• Other Authors: Blanco, J. A.
• Format: Book Part
• Language: English
• Published: IntechOpen 2011
• Subjects: glaciers; global warming; temperature; mass balance; The Arctic; Greenland; The Alps; Arctic; glacier; Global warming
• Online Access: https://research.manchester.ac.uk/en/publications/5711f234-f028-439d-a1a5-e659c0ec8a0e; https://pure.manchester.ac.uk/ws/files/54103131/Braithwaite_2011_Why_do_we_expect_glacier_melting_to_increase_under_global_warming.pdf

Media stories about global warming almost always mention “melting glaciers” and their effects upon global sealevel. The reader might therefore ask why the title of this chapter includes a question mark. It may seem blindingly obvious that global warming will cause a rise in global sealevel with a substantial contribution from melting glaciers, but the reasons are less obvious despite the copious literature. For example, the IPCC assessment reports 1991, 1996, 2001 and 2007 all include many references to published papers on glaciers (IPCC, 2011). These are admirable summaries of who has said what, or who has done what, but they do not explain why. My purpose for the present chapter is to provide a clear narrative on why we expect glacier melting to increase with any change in temperature, whether due to global warming or to natural fluctuations. By its very nature, the why of increased glacier melting must also answer the question of how much extra melting? The present chapter demonstrates empirically that higher melt is associated with higher air temperature. I do this in three stages: (1) correlating daily melt with daily air temperature for some Arctic and/or Greenland locations, (2) linking the results to the wider literature on the degree-method, and (3) showing that recent changes in glacier mass balance in the Alps are consistent with higher air temperatures in and around the Alps.