Campaigning by climate activist Greta Thunberg and filmmaker-naturalist David Attenborough is persuading pollution-conscious fliers to try and mitigate the environmental damage caused by their flights.
Sales of so-called carbon offsets are soaring: Myclimate, a Swiss nonprofit whose clients include Deutsche Lufthansa AG, reported a five-fold uptake in its credits in a year. At Ryanair Holdings, Europe's largest discount carrier, the number of customers making voluntary offset payments has almost doubled in 18 months.
This summer's heatwaves have boosted sales. Europe has seen rivers dry, temperature records fall and sporting events cancelled in heat scientists blame on man-made global warming. The offsets may offer a salve to the emerging "flight shame" anti-flying movement spreading from Sweden, home of 16-year-old Thunberg, who recently said she's crossing the Atlantic by sailboat to attend a United Nations climate summit in New York.
Carbon offsets are certificates that mitigate a passenger's flight emissions by reducing greenhouse gases elsewhere in the world. The money passengers pay on top of their ticket goes to low-carbon or clean energy projects such as planting trees, installing solar panels or handing out cleaner cooking stoves.
For example, on the website of Atmosfair, a German nonprofit, offsetting a one-way flight from London to New York can cost from $40 to $93 depending on the airline. Such a trip emits about half a ton of carbon emissions per passenger.
Putting a value on the offsets is difficult because different projects cut greenhouse gases in a wide variety of ways. Global voluntary offsetting transactions, which include at least some flight credits, reached a value of about $200 million a year, according to a first-quarter 2018 survey by Forest Trends.
The option to offset air-travel emissions has become public discussion, said Anne Thiel, communications manager for Washington-based Verra. While media attention and European heatwaves may have boosted offsetting, the yearly increase may be due to a more general growing appreciation of the problem, she said.