Andean glaciers are "ultra-sensitive" indicators of climate change, capable of recording variations that occur even within a decade, says a team of Ecuadorian and French researchers.
Bernard Francou, of the French Institute of Research for Development, and colleagues spent eight years documenting the relationship between the El Niño - Southern Oscillation (ENSO) — a periodic warming and cooling of the Pacific Ocean and associated changes in air pressure — and the erosion of glaciers in Ecuador.
Their results, published this month in the Journal of Geophysical Research, indicate that there is a tight and quantifiable link between ENSO events and the accelerated melting of the Andean glaciers.
Neil Glasser, of the University of Aberystwyth, United Kingdom, says the findings themselves are unsurprising and confirm a previous 'hunch' held by glaciologists.
More importantly, he says, the researchers' "huge effort" in maintaining an eight-year monitoring programme in a difficult environment suggests that past El Niño events could be precisely read in Andean ice cores.
Since understanding past climate change is essential to predicting future events, this could be an invaluable tool. Currently, data on past El Niño events has come from meteorological measurements and records of sea-surface temperatures. But data recorded this way covers only the past few decades.
The sort of data that could be extracted from ice cores, however, would provide information on events that happened from a century ago up to the present day.
at the Antizana station
Francou agrees with Glasser on this point, but cautions that this will require more research, as 'reading' the indicators in high-altitude ice cores can be very complex.
In the short term, says Glasser, the melting of the glaciers could be seen as good news for the communities living on the slopes beneath them who rely of melting ice for water supplies. In the long term, however, it means that their water supply will gradually dry up as the glaciers are melting faster than the ice is reforming.
Commenting on the value of Francou's team's measurements, Glasser said they would help predict the future rate of run-off from the glaciers. This could in turn help communities plan their water usage.