Glacier guardian

For over 20 years, Bernard Francou has been probing glaciers high in the Andes for clues to the future of our planet. Selected as an Associate Laureate in 2000 for his project to extract an ice-core from Ecuador’s Chimborazo volcano, he now wants to make the public aware of a growing threat – to glaciers and to the millions of people living in the foothills of the Andes.

In 2000, French glaciologist Bernard Francou had one goal in mind: to add to the store of knowledge about the planet’s climate by analysing ice accumulated on top of Chimborazo, an Ecuadorian volcano rising to 6,268 metres.

He chose this giant of the Andes for a definite reason. Situated just one degree away from the Equator, straddling the Pacific coast and the Amazon region, Chimborazo has long been a silent witness to El Niño and La Niña. By examining a 50-metre-deep ice core taken from the glacier, Francou hoped to track fluctuations caused by these weather phenomena over thousands of years and provide fresh input for the current debate on climate change. He points out that the ice functions like a weather recorder, a multi-tiered cake every layer of which is a source of invaluable information. The ash, micro-organisms, chemical substances and isotopes contained in the core allow him to read and understand meteorological events thousands of years old.

In 1999, Francou, who is based in Quito, where he is director of research at the French Institute for Research and Development (IRD), had drilled a very promising first core in which the ice had confirmed the climate variations of recent years.

But the next drilling, in 2000, brought an unwelcome surprise – a body of water 25 metres beneath the surface. This was caused by the recent eruption of a neighbouring volcano, Tungurahua, which had spewed ashes towards Chimborazo. The grey particles land on the ice, impaired its reflective power. The ice absorbed the sunlight and began to melt. The water in the ice cap started to percolate, draining away the chemical elements targeted by the study and interfering with the results.

“We drilled elsewhere to get around the water,” Francou explains, “but we realized that everywhere the ‘profiles’ had been altered by the surface water. Temperature readings under the ice were 0?C – melting point! – instead of the –10?C we expected.”

The drilling was put on temporary hold, but did not stop Francou’s visits to the volcano, where he casts a critical eye over the summit plateau. “Before,” he says, “the cap was well rounded and smooth. Now it’s more angular, and the crater of Chimborazo may well appear at the surface in a few years time.”

A geologist by training, Francou is no stranger to mountain glaciers – he’s been climbing them since the day, over 20 years ago in Bolivia, when he was deep in a discussion with hydrologist and colleague Pierre Ribstein. As they talked, Francou happened to glance at the peaks of the Cordillera Real mountains. The peaks were sparkling and it suddenly occurred to Francou that they were melting.

Francou and Ribstein have shared an interest in these glaciers ever since. In 1991, the two men installed instruments to measure changes in mass on one of them – Zongo. They then expanded their research, equipping other glaciers in the chain with complex apparatus to monitor the influence of the atmosphere on their surface. Officially recognized by the French authorities as an Environmental Research Observatory in 2002, the network initiated by Bernard Francou now encompasses a dozen Andean glaciers in three countries – Ecuador, Peru and Bolivia – making it possible to obtain a regional image of the changes. It is, to date, the only network of its kind in the tropics. Zongo has been under constant observation for 18 years and is now a useful point of reference for scientists.

At over 5,000 metres above sea level, tropical glaciers are particularly sensitive to climate variations. The IRD and its partners collect and use information from them in various ways, as Francou explains: “On the one hand, we produce data that enable us to measure the rise in temperature on these high-altitude territories, where there are few weather stations. On the other, we simulate what will happen in the future. Using regional scenarios based on degrees of greenhouse gas emissions, we can calculate the changes in the ice mass and tell the public and the authorities how much of the ice will remain if, for example, temperatures rise by 2.5?C by 2100.”

He believes the disappearance of the ice can be blamed in equal parts on global warming and on the warm phases (El Niño) of the tropical Pacific, which were very strong and frequent between 1976 and 1998. “The cold events [la Niña], like the one that started in September 2007, only temporarily slow down the decline. In the 30 years from 1976 onwards, the glaciers of the Central Andes lost almost half their surface area. And the situation is much worse for the small glaciers, like the Chacaltaya.”

Located just above the Bolivian capital, La Paz, Chacaltaya guaranteed great skiing for many years at the world’s highest downhill ski run – 5,380 metres above sea level! Until the early 1990s, sports fanatics would come from afar to ski down its famous slopes, which they reached on an old ski lift.

Today, the ski station is windswept and almost empty. The glacier has almost melted away. All that is left are three white patches several dozen metres across. How much longer will they last?

Alvaro Soruco, a young Bolivian researcher who has just finished his doctoral thesis in Grenoble, France, under Francou’s supervision, has demonstrated that since 1975 the glaciers of the Cordillera Real have lost half their volume. At the same time, Soruco points out that meltwater from glaciers contributes an average 15 per cent of the Bolivian capital’s water supply, and up to 27 per cent during annual periods of little rainfall.

“So far,” says Francou, “the retreat of the glaciers has had little impact on water resources, because the meltwater has made up for the reduction in the stock of ice. But that won’t always be the case.” And while the total disappearance of the 2,000 square kilometres of Andean glaciers is said to represent a mere drop – one third of a millimetre – in the rise in ocean levels, the question of the water supply in these regions is becoming urgent. The glaciers are natural reservoirs. If they disappear, what will happen to irrigated crops, to water supplies for towns and to the production of hydroelectric power?

“This resource will decrease,” says Francou, “and the effect will be felt especially strongly in the dry season. The number of dams and their size will have to be increased so that they can act as hydrological regulators when the glaciers no longer can.” In the future very clever management of water resources will be required in regions that are already under demographic and economic pressure – and time is running out for governments to come up with viable solutions.

For the indigenous communities in the Andes who live at the foot of these sacred mountains that they believe are inhabited by spirits, things are already changing. They have closely observed – not very scientifically but with great respect and concern – the retreat of the glaciers.

“In Peru,” says Francou, “the ice removed the Qolquepunco during the annual pilgrimage of Qoyllur Ritt’i is traditionally supposed to regenerate the Indian communities. The chiefs recently gave up the ritual so as not to make things worse.” And in Ecuador one man, Ushca, the heir to a fraternity whose members (hielero) once scaled the Chimborazo to bring back blocks of ice to sell in the valley, has not seen snow fall in nearly 20 years!

Aged 60, Francou is already planning how to pass his expertise on to others in order to ensure awareness of the phenomenon. This fresh-air enthusiast accustomed to doing field research is sacrificing time outdoors to spend more time at his desk, writing articles, overseeing theses, preparing lectures. He also helped draft the fourth report of the Intergovernmental Panel on Climate Change (IPCC), which, together with former American Vice-President Al Gore, was awarded the 2007 Nobel Peace Prize. “A grain of sand”, he says with a modest smile. “I contributed a few sentences to this monumental work co-written by over 3,000 researchers, which has the merit of being the only credible major synthesis on climate change.”

Bernard Francou strongly hopes that the report will be rapidly translated into political action.
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