Worldwide Occurrences and Attribution of Moraine-Dammed Glacier Lake Outburst Floods

Most mountain glaciers have been receding from their late historic positions during the last century and the rate of recession has increased over the past decades largely as a consequence of global warming.  Because glaciers are coupled to their slope and valley-floor geomorphic systems, recession impacts upon these in a number of complex ways, producing a range of natural hazards that have severe impacts on downstream communities and infrastructure.  The most important of these are glacial lake outburst floods (GLOFs).  

We have produced a global database of recent moraine-dam failures leading to GLOFs.  The data show an abrupt increase in the frequency of GLOFs around 1930, a peak in GLOF frequency in most mountain regions in the 1960-80s and a reduction in frequency since then.  The general global picture is one where the post-1930 increase in GLOFs is attributed to a possible delayed response to the warming since the Little Ice Age, but the lack of a surge of GLOFs after 1930 does not support a link between anthropogenic warming and recent GLOFs.

Here, we discuss this pattern of GLOFs and discuss this in the context of paraglaciation and the concept of climate sensitivity.  We use these ideas to assess three things: the geomorphological implications of current and future glacier recession; GLOFs and climate change attribution, and the policy implications of paraglaciation.