Glacial Melt Will Wreck Ecosystems

The alarming rate of glacial shrinkage worldwide threatens our current way of life, from biodiversity to tourism, hydropower to clean water supply.

Glaciers cover one-tenth of the planet’s land surface – but not for much longer.

Glaciers worldwide are in retreat, and losing mass. They are shrinking and melting, and that will create problems almost everywhere, according to new research.

Between 2003 and 2009 glaciers melted on a gargantuan scale,  with an estimated 1,350 cubic kilometers of meltwater streamed from what had once been vast streams of slowly flowing ice.

Ice has been in retreat in the Gulf of Alaska, the Canadian Arctic, Greenland, and Antarctica. In the European Alps summers have become measurably warmer during the last 30 years, snowfall has diminished and 54% of the ice cover in the mountains has disappeared since 1850.  By 2100, Alpine summits may have lost around nine-tenths of the ice that still covered them in 2003.  In South America, the glaciers of Bolivia lost almost 50% of their mass in the last 50 years.  In western Canada, somewhere between 60% and 80% of the ice measured in 2005 will have disappeared, and flowed into the sea to raise sea levels everywhere.

And, says an international team of scientists, in the Proceedings of the National Academy of Sciences, the loss of mountain ice creates problems for the people who live downstream.

Glaciers in the basins of the Ganges, Brahmaputra, and Indus rivers are right now losing 24 billion metric tons of ice a year:  between 2003 and 2009, that added up to about a tenth of all the glacial ice lost everywhere in the world.  Ice loss upstream means changes in the timing, magnitude, and frequency of the flows downstream, and that in turn affects the levels of sediment, and the nutrients, both for the human populations who depend on the farmland in the valleys and plains below, but also for the natural ecosystems in the rivers, lakes, and coastal zones.

It is time, the scientists argue, for some serious thinking: glacier loss cannot be separated from complexities such as changes in natural hazards such as flooding and drought, in agriculture, tourism, hydropower, cultural life, and political economy.

“We don’t believe that the sheer enormity of the impact of glacial shrinkage on our downstream ecosystems has been fully integrated to date.  From biodiversity to tourism, from hydropower to clean water supply, the breadth of risk to our current way of life is vast.  The first step must be a realignment in how we view glacial shrinkage, and a research agenda that acknowledges the risk to regions likely to be most affected,” says Alexander Milner, professor of river ecosystems at the University of Birmingham in the United Kingdom, who led the study.  “We don’t believe that the sheer enormity of the impact of glacial shrinkage on our downstream ecosystems has been fully integrated to date.  From biodiversity to tourism, from hydropower to clean water supply, the breadth of risk to our current way of life is vast.  The first step must be a realignment in how we view glacial shrinkage, and a research agenda that acknowledges the risk to regions likely to be most affected,” says Alexander Milner, professor of river ecosystems at the University of Birmingham in the United Kingdom, who led the study.

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