Staff stay on duty outside the Waliguan Background Station. (PHOTO: XINHUA)

By LIN Yuchen

At the Waliguan Mountain top in the Qinghai-Xizang Plateau stands the Waliguan Background Station. As the only global atmospheric background station of the World Meteorological Organization (WMO) established in the hinterland of Asia and Europe, it aims to monitor background concentration levels of air polluting substances significant for the globe as a whole, and measure long-term changes in the composition of the atmosphere.

Since its establishment in 1994, using the huge amount of data accumulated in the past 30 years, the station's research team has drawn the industry-famous curve on the carbon dioxide concentration changes between 1995 and 2015. The data shown in the curve are compatible with the results from the Mauna Loa Observatory based in Hawaii and provided the basis for the continuing trend of increasing global greenhouse gas concentrations across the world.

Strict selection of location

Waliguan Mountain is located on the Qinghai-Xizang Plateau dubbed "Roof of the World," with an average altitude of more than 3800 meters. It has a lowest temperature of minus 25 degrees Celsius and no one lives within a 10 kilometer radius.

Established in such conditions, the Waliguan Background Station ensures proper atmospheric background observation procedures in accordance with WMO's standards, meaning larger pollution sources should be more than 40 km away from the monitoring station. In the next 50 years, the surrounding area of the monitoring station within 30-50 kilometers will have no significant change in land use such as major residential areas, industrial areas and highways. These should all remain at the required distance from the monitoring station.

Atmospheric background observation is designed to obtain data on the concentration of each element in the global atmosphere without human interference, said Zhang Guoqing, director of the Waliguan Background Station, adding that to meet the strict requirements of WMO, experts eventually decided to build China's first global atmospheric background station in 1992 at the Waliguan mountaintop, after years of on-site investigation.

Difficulties and trials faced by staff

The problem that comes with such a selection of location, however, is the difficulties staff have to overcome as stay on duty on-site. 

Staff go outside three times a day for observation work; each time they must follow strict time requirements, said Huang Jianqing, an observation staff member of the Waliguan Station, who notes that certain factors related to the climate may have already changed even if they arrive one minute late.

Another staff member, Zhao Yucheng, said that in the early years of the station, every time they went up the mountain for their shift, they purchased food in advance that could sustain them for at least 20 days. He said they would need to make over 20 turns along a 7-kilometer-long mountain road in order to get to the mountaintop where the station lies.

Within duty time, they must pay meticulous attention to each section of work, including monitoring the weather, inspecting devices and collecting atmospheric samples. Any subtle mistakes in these processes could lead to incorrect observation results.

Green dividends

Some disagreed at the early stages with the decision of building a background station in such harsh conditions, worrying about the effect on the environment.

However Han Fulong, county head of the Gonghe County, said that it was the construction of the Waliguan Background Station that propelled Gonghe toward sustainable development. He said that today, a third of the county's land has been designated as an ecological protection area.

Such ecological efforts have brought about green dividends. The county vigorously develops clean energy with wind power, photo-electricity and hydropower as the three major industries, and is committed to becoming a national clean energy demonstration site. In 2020, Gonghe ranked first in the county ecological evaluation in Qinghai province.

"Our greatest responsibility is to ecology, the greatest potential is in ecology and the greatest value also in ecology," said Han.

Currently, the Waliguan Background Station generates more than 60,000 observation data within 24 hours a day, covering all major atmospheric components. The station is also cooperating with universities and research institutions at home and abroad to jointly conduct dozens of scientific studies and experiments.