Measuring the carbon footprint of browsing cookies
Advertising technology is the primary source of revenue that forms the economic connective tissue of the Internet. But as the world struggles to shift from fossil fuels to creating energy, what that energy powers is coming under increasing scrutiny.
This reality led Barcelona-based artist and digital researcher Joana Moll to ask: what is the carbon footprint of advertising and cookie tracking infrastructure?
Over the past six months, Moll, together with a team of researchers from the Supercomputing Center of the University of Barcelona, has explored this question.
The result was the Carbolytic project, which calculated the carbon cost of browsing the cookies contained in the top 1 million most visited sites on the Internet, produced 11,442 tonnes of carbon dioxide per month due to the energy consumption required to power the calculation to maintain them. Each website left over 21 million cookies per visit from 1,200 companies, which equates to over 197 trillion cookies created per user per month.
Moll said that’s equivalent to the carbon footprint of a small European town of about 30,000 people over the same one-month period. Additionally, the carbon emissions data from Carbolytics are rough calculations meant to serve as a benchmark for future research aimed at further quantifying the carbon costs of digital living as the climate crisis deepens, Moll said. .
“Adtech is the main business model of the internet, but we know very little about how it actually works,” Moll said. “We are now in an environment where we have discussions about the initial phase of data extraction, which is personal privacy, and that is important. But we are not yet talking about the carbon cost of personal data mining and tracking cookies.
The project is a visual representation of all cookies located on the 1 million most visited websites. When a user visits the project, they are bombarded with thousands of logos they can click on and it will tell them what the cookie is, how many websites it is on, and how much carbon is emitted to power it.
“I wanted to create an overwhelming representation, because the adtech system is overwhelming and it’s non-stop,” Moll said. “You’re supposed to feel like these cookies waste a lot of energy.”
“So to protect your privacy, you’re adding another layer of carbon dioxide to the atmosphere,” Moll said. “No cookies should be set until a user gives consent. The (adtech) industry is hard to regulate because policy makers don’t understand how it works technically, and it’s changing so fast that Ordinary people won’t know where to go to begin to understand how it all works.
Carbolytics wasn’t Moll’s first exploration of measuring the carbon costs of living online. In 2019, Moll set out to measure the carbon cost of buying a book for herself through Amazon in a project titled “The Hidden Life of an Amazon User”.
In this project, to purchase an item from Amazon, Moll discovered that a user is guided through 12 interfaces with a litany of code on the back-end. She discovered that the code contained over 1,300 requests to various scripts and documents, and totaled 87.33 megabytes, or over 8,700 pages when printed. The energy required to load these 12 web interfaces and the code snippets for each was equivalent to approximately 30 watt-hours of electricity.
Therefore, Moll said claims by large multinational companies, such as Amazon, that have pledged to become “carbon neutral” by a certain date obscure the fact that they are in fact offloading much of their carbon costs on consumers.
“A company can claim that it is becoming carbon neutral, but you have to realize that it is only becoming carbon neutral in its operations over which it has direct control,” Moll said. “However, much of their online infrastructure is not owned by them, so the consumer bears that carbon cost instead of the business. So claims of a business becoming carbon neutral are essentially not true.
Moll said there was a major omission from Carbolytics, which was that not all of its calculations included the carbon costs of mobile app tracking cookies. She said including such data would have made the project too expensive, but if it had been, the carbon footprint of browser cookies would have been significantly higher.
“The real cost of carbon could be 11,000 times higher because we haven’t measured app activity,” Moll said. “So it’s important to realize that this is just the tip of the iceberg. It’s a new layer in the fight for digital rights – to understand the carbon cost of this whole industry.
Photo by Matthew Henry on Unsplash