Bolivian observatory collects data as glaciers melt

In this Oct. 8, 2018 photo, shows the entrance to the Chacaltaya atmospheric observatory, at Chacaltaya mountain, Bolivia. The station is an important

In this Oct. 8, 2018 photo, shows the entrance to the Chacaltaya atmospheric observatory, at Chacaltaya mountain, Bolivia. The station is an important

In this Oct. 8, 2018 photo, an employee walks next to air collector of the Chacaltaya atmospheric observatory, 17,192 feet (5,240 meters) above sea le

In this Oct. 8, 2018 photo, an employee walks next to air collector of the Chacaltaya atmospheric observatory, 17,192 feet (5,240 meters) above sea le

In this Oct. 8, 2018 photo, an air collector of the Chacaltaya atmospheric observatory stands in the outskirts of El Alto, Bolivia. In 2012, the site

In this Oct. 8, 2018 photo, an air collector of the Chacaltaya atmospheric observatory stands in the outskirts of El Alto, Bolivia. In 2012, the site

In this Oct. 8, 2018 photo, Fernando Velarde Bolivian physicist works in the laboratory at the Chacaltaya atmospheric observatory on the outskirts of

In this Oct. 8, 2018 photo, Fernando Velarde Bolivian physicist works in the laboratory at the Chacaltaya atmospheric observatory on the outskirts of

In this Oct. 8, 2018 photo, a computer screen shows a reading of various gases at the Chacaltaya atmospheric observatory laboratory, on the outskirts

In this Oct. 8, 2018 photo, a computer screen shows a reading of various gases at the Chacaltaya atmospheric observatory laboratory, on the outskirts

In this Oct. 8, 2018 photo, tourists walk on the outskirts of the Chacaltaya atmospheric observatory on the outskirts of El Alto, Bolivia. The Chacalt

In this Oct. 8, 2018 photo, tourists walk on the outskirts of the Chacaltaya atmospheric observatory on the outskirts of El Alto, Bolivia. The Chacalt

LA PAZ, Bolivia (AP) — The snow appears to be pristine on the Andean peaks that loom above Bolivia's capital, but even here ash and smog reach up to a remote plateau that is home to the world's highest atmospheric observatory.

It's an ideal site for a team of international scientists who collect data on pollution that has contributed to the rapid disappearance of Andean glaciers.

Research at the Chacaltaya station, which is located at 17,192 feet (5,240 meters) above sea level, has a pressing urgency: The retreat of glaciers, which is compounded by global warming, threatens the main source of fresh water for residents in the nearby cities of EL Alto and La Paz — and the crops on which they rely.