Published on January 23rd, 2013 | by Joshua S Hill
Climate Change At Fault For Massive Andes Glacier Melting
New research into the continued decline of glaciers around the planet is not new, yet nevertheless these studies remain critically important to understanding our impact upon the environment and the sort of world we will be living in ten years from now.
The most comprehensive review of Andean glacier observations to date was conducted by an international team of researchers, looking at data collected over several decades, in some cases all the way back to the 1940s.
The study looked at data collected from glaciers in Colombia, Ecuador, Peru, and Bolivia, covering a total of almost a thousand square kilometres, an area corresponding to approximately 50% of the total area covered by glaciers in the tropical Andes in the early 2000s.
What they found was discouraging, at best.
Glaciers in the Andes have been decreasing at an increasing rate since the 1970s, a retreat the scientists blame on rising temperatures in the region which have warmed about 0.7°C over the past 50 years (1950-1994) — an explanation that holds even more water (pardon the following pun) considering that there has been no change in the rainfall level in the region; a change in rainfall could have explained the glaciers retreat. To top it off, the researchers determined that the glacier decline has no corollary in the past 300 years.
Unsurprisingly, glaciers have been retreating since the decline of the Little Ice Age, some 160 years ago. Worryingly, however, is the fact that the most recent few decades have seen an increase in that retreat in the tropical Andes — a region the Intergovernmental Panel on Climate Change noted would be a key indicator of climate change, as tropical glaciers are particularly sensitive to temperature changes.
The scientists found that tropical glaciers in the Andes have shrunk by an average of 30% to 50% since the 1970s. They also determined that glaciers at altitudes below 5,400 metres were especially vulnerable, having lost 1.35 metres in ice thickness per year since the late 1970s. That’s twice the rate of the larger glaciers at higher altitudes.
“Because the maximum thickness of these small, low-altitude glaciers rarely exceeds 40 metres, with such an annual loss they will probably completely disappear within the coming decades,” says Antoine Rabatel, researcher at the Laboratory for Glaciology and Environmental Geophysics in Grenoble, France, and lead author of the study.
Information such as this research has revealed does not just explain what has happened or is happening. We understand that anthropogenic warming has had a deleterious effect on the planet, noticeably in tropical glacier regions such as the Andes.
However there are immediate problems that the region will now have to face as a result of this retreat.
Meltwater from glaciers is often a major source of drinking water for those living below the glaciers. “The ongoing recession of Andean glaciers will become increasingly problematic for regions depending on water resources supplied by glacierised mountain catchments, particularly in Peru,” the scientists write. Particularly, the Santa River valley in Peru will be devastatingly affected, with water shortages expected for the hundreds of thousands of residents who have depended upon meltwater for agriculture, domestic consumption, and hydropower.
Additionally, Le Paz – the seat of Bolivian government – with a population of nearly 3 million people, could be affected by water shortages. “Glaciers provide about 15% of the La Paz water supply throughout the year, increasing to about 27% during the dry season,” says Alvaro Soruco, a Bolivian researcher who took part in the study.
These South American countries may seem far away and easily ignored, but their experiences represent ecological repercussions that will soon affect us all, no matter where we live.
Source: European Geosciences Union