"Carbon is not the enemy." So says designer William McDonough, the author and architect and inventor of the concept of "cradle-to-cradle," who wants to change how we talk about carbon—and by extension, how that language shapes the design of society.
In the climate conversation now, almost all references to carbon are negative. We talk about needing to aim for "low carbon," and "zero carbon," and "decarbonization." It's all shorthand for excess carbon dioxide in the atmosphere. But McDonough thinks that it's framing the problem (and solutions) in the wrong way.
"Carbon is always treated as a bad thing; it has a bad name," he says. "And I find that sad because carbon is a source of life."
Humans are made of carbon. The plants and animals we eat are made of carbon. Carbon in soil is the basis of healthy ecosystems. When carbon is locked up inside diamonds or recycled in plastic, it's a useful tool, not a pollutant.
In a new article in Nature, McDonough argues for new phrases. "Living carbon" is growing in biological cycles. "Durable carbon" is locked inside stable solids, like the wood inside a building or the paper in a book. Only "fugitive carbon"—carbon that has ended up somewhere unwanted, like carbon dioxide released into the atmosphere—is a problem.
Clarifying when carbon is problematic might help make it more obvious when some "sustainable" processes really aren't. "If you burn the plastic in waste-to-energy plants, they call it renewable," McDonough says. "That's silly because you're burning the plastics and putting them where? In the atmosphere. That becomes fugitive carbon. You've converted durable to fugitive."
He also argues for new definitions for "carbon neutral," "carbon negative," and "carbon positive."
Right now, a company might say that it's "carbon neutral" or "net zero carbon" if it's offsetting its greenhouse gas emissions by purchasing renewable energy somewhere else. But that still means "fugitive" carbon will end up in the atmosphere.
"If I said to a child in Flint, Michigan, 'We're going to let you be 'net zero lead,' because we're going to go to New Jersey and take lead out of the water where it's cheaper to do, equivalent to that which is in your water. So you're now net zero lead'—pathetic," McDonough says.
Similarly, burning wood for fuel is often considered "carbon neutral," because people argue that they've replanted trees that take in an equivalent amount of carbon. But trees sequester carbon at different rates, and the process can take decades.
McDonough proposes that "carbon neutral" should only apply to things that are truly neutral—for example, capturing carbon in durable products that can be used and recycled over generations, or the use of solar power.
While "carbon negative" is often used to mean taking carbon out of the atmosphere, McDonough makes the point that "negative" is confusing. Instead, he thinks that acts that capture carbon should be called "carbon positive," and those that cause carbon pollution should be called "carbon negative."
Using this new framework, he thinks that people can begin to think about how to use carbon safely and productively. While companies and cities are often now focused on reducing emissions—what McDonough calls "being less bad"—he argues that they should also focus on a positive goal for the future.
"If their goal is zero carbon emissions, these are very worthwhile things to do, but it's also telling people what you're not going to do," he says. "It's like telling a taxi driver, 'Quick, I'm not going to the airport.'"
A better goal, he says, is to aim for something like 100% renewable energy. Ultimately, he thinks that cities and companies can fully shift to "carbon positive" designs that help rebuild soil and support life.
A solar power plant, for example, could move from a "neutral" design to a "solar orchard" model, where panels are placed to allow grass to grow underneath and sequester carbon; sheep can graze among the solar panels, so the net effect of the farm is positive.
Buildings, such as one that McDonough recently designed for Oberlin College, can also be carbon positive. The building purifies wastewater and sewage on site, turning it into rich compost. It also produces more solar power than it uses, and once battery storage improves, can start sharing that energy elsewhere.
"Such designs offer an inspiring model for climate action," McDonough writes in Nature. "It all starts with changing the way we talk about carbon."