Deep inside the layers of ice sitting atop the Andes Mountains in Peru is evidence of the earliest human-caused air pollution. Within the core of the 1,200-year-old Quelccaya Ice Cap, scientists have found traces of lead and mercury, the chemicals used after the Spanish occupation, in the silver mines of Potosi, Bolivia.
Glaciers are melting and air pollution is the cause
“Glaciers receive trace elements exclusively from the atmosphere and can therefore be used to precisely assess the possible large-scale impact of anthropogenic activities through time,” the report by the Byrd Polar and Climate Research Center of the Ohio State University, said. “Today, there are no glaciers on Earth where atmospheric deposition of anthropogenic origin cannot be detected."
Mountain glaciers have been in retreat for several decades, but what scientists are now learning is the considerable factor air pollution plays in their decline. According to the research by the National Institute of Research on Glaciers and Mountain Ecosystems (INAIGEM) in Peru, black carbon encourages the melting of snow or ice in the glaciers of the Cordillera Blanca, in Peru, as it intercepts and absorbs sunlight.
“There are different sources of black carbon that can deposit on glaciers, some are wildfires, burning of agricultural waste, and the emissions from vehicles fleets,” Jesús Gómez López, Director of Glaciers Research at INAIGEM told UN Environment. “Studies show that the concentration of black carbon is greater in glaciers close to large cities, as is the case of Huaraz, compared to the more distant city of Yungay.”
Scientists predict that as glaciers melt, cities and towns close to them will initially have more water. But over time, the water the glaciers supply will dwindle, and some may even experience avalanches and floods. The effects in Peru, too, could be far-reaching, particularly on Peruvian agriculture and on freshwater for Peru’s capital city, Lima, threatening the livelihoods of millions of people.
The Ohio-based researchers admit that despite human-caused air pollution existing as far back as the Spanish Conquest, what we can find in the 20th century is unprecedented “over the entirety of human history.”
López, like other scientists, believes that the melting of glaciers could be curtailed if we took measures to reduce air pollution and invested in the conservation of mountain ecosystems with glacial headwaters.
“The amount of black carbon that travels to glaciers could be reduced by merely avoiding wildfires and the burning of pastures or agricultural waste, and if greater control over the emission of gases from vehicles and industry were made,” he said.
Governments and authorities can also consider improving management of water resources, by creating more efficient irrigation systems; refining water quality in rivers near cities; and carrying out reforestation of species that contribute to preserving mountain ecosystems.
UN Environment is working in Peru and many countries alike, to help develop and improve policies for healthier ecosystems. These include programmes to encourage the clean fuels standards, the uptake of electric mobility, better public transport systems and air quality management.
“At the national scale, a key step to managing air pollution is being able to measure it,” said Sean Khan, head of Un Environment’s Global Environmental Monitoring System Unit.
“Understanding its sources, patterns and trends are important to understand if we are to abate its impact on people and ecosystems. Peru is already exploring the suitability of low-cost sensor technology to measure trace gases and fine particles in the air and identify pollution hotspots.”