Each year, an estimated 53,000 tourists visit Antarctica, and they could each be unwittingly contributing to the melting of 83 tonnes of snow, according to a new study published in Nature Communications.
The culprit is black carbon, aka soot, created when fossil fuels and biomass are burnt. Black carbon settles on the snow, causing it to darken in colour. This increases the absorption of heat from the sun and accelerates melting.
Due to its remoteness, Antarctica has a low background level of black-carbon pollution compared to other parts of the world. However, the new study indicates that black carbon from Antarctic tourism and research activities has nevertheless had a notable effect on the icy landscape.
The international research team measured black carbon concentrations in snow collected from 28 sites along a 2000-kilometre stretch of the northern Antarctic Peninsula. The researchers found that black carbon levels were higher near research facilities and landing sites for tourist vessels than at more remote regions of the peninsula.
The study estimates that, in heavily impacted areas, black carbon pollution is causing snowpack to shrink by up to 23 millimetres each year. Altogether, an estimated 4.4 megatonnes per year of snow is melting more quickly in the summer due to the impacts of black carbon from tourism alone – translating to 83 tonnes per visitor.
“It is likely that local emissions account for most of the BC [black carbon] content in samples collected around research facilities and popular shore tourist-landing sites,” the paper states.
Ships, aeroplanes, helicopters, generators and trucks are known sources of black carbon that can settle on snow. The study authors suggest that tourist cruises and fuel-powered equipment at scientific research stations are likely the largest sources of black-carbon pollution in the study area. That’s despite efforts in recent years to reduce the environmental footprint of Antarctic tourism, such as switching to marine diesel or supplementary battery power.
“Our results show that more remains to be done to reduce the impacts of tourism and ships in Antarctica,” the authors write.
The news comes on the heels of an announcement by the Australian Federal Government of an $800-million investment in Antarctic activities, which includes funding for research as well as for drones, helicopters and other vehicles.