A few days ago I saw the documentary ‘Chasing Ice’ which is a hauntingly beautiful account of the rapid demise of glaciers and ice sheets around the world. It is based on the work of James Balog, a National Geographic photographer, who has been running the Extreme Ice Survey since 2007. This is a ground-based photographic glacier study across the Northern hemisphere that is providing a unique chronicle of climate change. Indeed Balog refers to glacial retreat as the ‘canary in the mine’, providing a very vivid visual indication of early environmental impacts. The film seems to be developing the same momentum as Al Gore’s documentary ‘An Inconvenient Truth’ did in 2006.
Last week an iceberg slightly larger than the City of Chicago (720 km2) separated from the Pine Island Glacier in the Antarctic. About ten percent of the West Antarctic Ice Sheet, drains through this glacier, which has started to move much more rapidly over the last forty years. This speed up has led to the glacier losing up 46 gigatonnes of ice per year (equivalent to 0.13 mm per year global sea level rise). The choice of Chicago as a benchmark by the media is ironic, since the source of much of Chicago’s drinking water is Lake Michigan, which was formed by glaciers about 14,000 years ago. The diversion of fresh water for the city and its surrounds is up to 2.1 billion gallons a day. Hence this single iceberg would keep the city supplied (if they didn’t mind the salty water) for about 16 years!
Whilst these staggering numbers support the well-documented projections of global warming, glaciers themselves are also highly significant for a number of countries around the world with regard to their water supply. Mountain glaciers that provide water for human populations can be particularly sensitive to increasing temperature and those at lower elevations are even more susceptible. The Andes have the majority of the world’s low-latitude tropical glaciers and many of these are expected to disappear over the two decades. The Chacaltaya glacier in Bolivia, for instance, completely disappeared in 2009.
In the Andes Cordillera the demise of these glaciers will be extremely damaging since up to 30 million people depend heavily on their water. Initially, higher rates of glacial melt will release hundreds of years of stored water providing short-term benefits, but in the long-term glacial water will diminish. The World Bank and other agencies / NGOs are supporting the development of adaptation plans for climate change in the river basins of Bolivia, Ecuador, and Peru. Options being assessed include alternative water supply sources, water demand management and engineered water storage.
In the power sector particularly, big changes may occur; significant amounts of the energy supplies for Peru, Colombia, Ecuador and Bolivia are dependent on hydropower from glacial meltwater. Future options include power rationing or diversified energy supplies that will most likely be based on fossil fuels. This will lead to higher energy costs and increased carbon emissions in the region. Andean communities also need to adapt agricultural practices to climate change, which will require transitions to alternative crops and irrigation systems.
Do you have any first-hand knowledge of melting glaciers? Have you heard of innovative techniques being used to deal with this? Share your comments in the section below: