In 2019, Sanchali Pal decided she’d had enough of spreadsheets. For six years, the former consultant had been using Excel to manually track the carbon emissions of her purchases, a routine she says saved her about $2,000 a year by encouraging more secondhand shopping, fewer flights and less meat consumption. But the DIY approach was getting tedious.
So in August of that year, Pal launched Commons, a smartphone app that tracks the carbon footprint of users’ spending, offers cash back for sustainable choices and sells carbon offsets. Today, Commons has tens of thousands of users, whom it says are able to reduce their annual emissions by 19% on average using the app. If everyone in the U.S. achieved that reduction, Pal says it would be the equivalent of taking 80% of cars in the U.S. off the road.
Commons has plenty of company. There are now more than a dozen apps aimed at helping users keep tabs on their individual emissions. Tracky uses GPS to target travel-related emissions. With Pawprint, employers can help their employees measure their carbon footprint and weigh in on sustainability initiatives in the workplace. Klarna pairs emissions-tracking with other financial services offerings. The Carbon Games gamifies carbon reduction by giving its users in-app green challenges and displaying competitive leaderboards.
Pal says her goal is to help consumers build a "carbon intuition."
"The way I think of it is, if something saves you $1 or $2, you don’t have to worry about it,” she says. "But if something saves you $300, you would." Likewise, "if something is a 100-kilogram [of CO2] decision, you should probably think about it."
Calculating emissions for individual purchases is harder than it sounds. The amount of carbon dioxide produced by a flight or a piece of meat is measurable and relatively concrete. But the emissions footprint of, say, a new smartphone — made of materials from myriad carbon-intensive supply chains — can be much more difficult to quantify. Even something as simple as buying a shirt is often a carbon-accounting mess.
Commons’ methodology, inspired by Pal’s original spreadsheet, starts with user-submitted information about location, transportation and lifestyle. Users then link their credit and debit cards to the app, which multiplies the total of each purchase by an emissions intensity value based on data from Oxford University, Yale University, the U.S. Energy Information Administration, the U.S. Environmental Protection Agency and other institutions. (The app can only track emissions for users in the U.S. and Canada.)
To manage its own emissions-tracking, Klarna — the Swedish fintech company best known for its "buy now pay later" offering — partnered with the AI carbon-management company Vaayu. Data from purchases made through Klarna’s app, website or its third-party payment option are compiled on the Klarna app to show users their total emissions and high-impact purchases. Klarna says it has data for 150 million products across categories that include home and gardening goods, jewelry, accessories and electronics.
While Commons says its main goal is changing consumer behavior, the company also invests in carbon-dioxide removal (CDR) projects. And to counteract a certain portion of their monthly footprint, subscribers can pay the app to automatically offset their emissions. (Klarna also invests in CDR projects, but does not sell offsets.)
Offsets remain controversial, and studies have repeatedly shown that most of them overpromise. A recent review of more than 100 such studies, conducted by the de facto global regulator of private-sector CO2 targets, declared carbon offsets largely "ineffective."
Pal concedes those limitations, but emphasizes the app’s larger goal of helping consumers make informed choices. "We can’t manage something if we can’t measure it," she says.
The push for more "carbon intuition" is also showing up at other consumer-facing companies. Many banks now offer green credit cards that support environmental investments. And retailers, airlines, and Big Tech companies are working emissions data and more "climate-friendly" options into everything from fashion certifications to flight results and driving directions.
Stuart Kirsch, a University of Michigan professor who researches carbon accounting, says there’s value in informing consumers. But he cautions that climate solutions need to happen on a structural level. "There’s also a class dimension to consumer choice," Kirsch says. "With certain brands, you can shop your way to better and more sustainable clothing, but you’re still consuming too much. Consumer choice can be a tool to absolve people of their guilt."
Indeed, carbon-tracking services straddle a tricky line between showing people the emissions impact of their purchases and implying that emissions are a problem individuals can solve.
Pal points to a report from the Intergovernmental Panel on Climate Change that suggests changes in demand-side behavior could reduce greenhouse gas emission by 40% to 70% before 2050. But economist Joyashree Roy, a coordinating lead author on that report, says institutional barriers — including cost — limit consumers’ ability to harness their influence.
"The most successful message we came across was that individuals are motivated, but they feel incapacitated because of a lack of access to the right infrastructure or technology," Roy says. "If your city doesn’t have the right access to infrastructure, right incentives, right nudging, right technology, then you can’t make the right choice."
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