By Martin Vennard
BBC News, Adigene glacier
Geologist Bakutbek Ermenbaev points up through the pine trees at the glacier above us in Kyrgyzstan's Alatau mountains.
"That one - called Adigene - has decreased in size by about 20% over the last 50 years," he says.
He adds that a neighbouring glacier, Aksai, has disappeared completely.
Mr Ermenbaev, who works for the government's hydrogeology agency, says global warming is to blame.
And he warns that unless action is taken to reduce this warming, all of Kyrgyzstan's 2,200 glaciers could have melted within a century.
The Kyrgyz glaciers and those in neighbouring Tajikistan are vital to the water supply of Central Asia.
"In normal circumstances the glaciers would melt in the summer season, but regain their size in the winter," Mr Ermenbaev says.
But he adds that on average the glaciers are now decreasing in size by 15-20m ( 50-65ft) annually. One glacier, Petrova, is retreating by 50m a year.
The hydrogeology agency has been monitoring the melting of the glaciers for the past 50 years and has one of its monitoring stations on Adigene.
"On average, all around the country, we can say the glaciers have decreased in size by about 20%.
"In the last 20 years this has been happening more rapidly than in the previous years," Mr Ermenbaev says.
We are standing by a fast-flowing mountain stream, less than an hour's drive from the capital, Bishkek, but we are already at more than 2,000m above sea-level.
The majority of Kyrgyzstan is mountainous and we are surrounded by snow-capped peaks.
Mr Ermenbaev says the size of the surrounding mountain lakes is further evidence of the effects of global warming.
"When a glacier starts melting it creates small lakes, and each year the size of those lakes is growing," he says.
He adds that when the lakes get too big, the water overflows and rushes down the valleys and gorges, potentially threatening the settlements in its path.
A number of homes and buildings were washed away in the gorge we are in, which is called Ala-Archa, in the late 1990s.
In Soviet times permanent building was banned in such areas and Mr Ermenbaev says the restrictions should be re-introduced.
He says the agency's monitoring work has been complicated by the fact that it can no longer get access to some land that has been privatised since the collapse of the Soviet Union.
Kyrgyzstan and Tajikistan's neighbours, such as Uzbekistan - which has a thirsty cotton growing industry - rely on the glaciers for their water supplies.
Mr Ermenbaev says that although the melting may appear to be good news for the downstream countries, providing increased supplies, it will lead to water shortages in the long term.
The melting glaciers feed lakes which can overflow, causing floods
Access to water resources has already created tension between countries in the region.
The glaciers provide a store of frozen water, which in the past was released gradually by the thawing and freezing process.
But even if the water is stored downstream in reservoirs it evaporates much more quickly than it would in colder temperatures at higher altitude.
"It's not good for the downstream countries to have a lot of water in their reservoirs which could evaporate without benefiting them," Mr Ermenbaev says.
He says that the short-term solution is to build dams on the mountain lakes, where the water can be stored for longer and its flow downstream can be regulated.
However, such projects are not popular with the downstream countries which do not want to see restrictions placed on their access to water.
Mr Ermenbaev says that the only long-term solution is to halt global warming, otherwise the mountain landscape could change for ever.