Comment: Carbon offset market is growing, but is it helping?

By Mark Gongloff / Bloomberg Opinion

It might seem tricky to chop down trees with one hand and sell climate absolution with the other, but the dubious math of carbon offsets makes it possible, at least for now.

Trees drink up carbon dioxide, the stuff that is warming the planet to dangerous levels. And aside from Uncle Sam, nobody in America owns as many trees as Seattle’s Weyerhaeuser, the biggest U.S. logger. Long a bête noire of environmentalists, the company is now using its 10.6 million acres of forest to declare it has so much green credit that it can sell some to other companies, the Wall Street Journal reported this week.

Weyerhaeuser claims its forests absorb 17 million metric tons of carbon a year. Its lumber and other products could freeze an additional 18 million metric tons in place for years or decades. This more than makes up for the 7.4 million metric tons of carbon its logging and other activities emit every year, by Weyerhaeuser’s estimation.

So the company has understandably jumped into the burgeoning trade of selling carbon credits to businesses and consumers trying to reduce their own emissions, with plans to bolster its carbon-storing capacity by pumping it into the ground. Weyerhaeuser expects this business to bring in $100 million in annual profit by 2025, according to the Journal. And the company’s greener patina could make it more attractive to the environmental, social and governance (ESG) investing set, boosting its stock price.

“I don’t think there are many companies in the world with a better environmental story than Weyerhaeuser,” Chief Executive Officer Devin Stockfish told the Journal.

Maybe. You could argue that every little bit of effort to take carbon out of the atmosphere is welcome. And Weyerhaeuser deserves kudos for tracking emissions all the way to its customers and vowing to winnow them to net zero by 2050, in keeping with the Paris Agreement to limit global warming to 1.5 Celsius.

It’s also true that logged wood can store carbon, as Weyerhaeuser notes. The lumber in a new single-family house might hold carbon for up to 100 years, according to the U.S. Forestry Service. Even paper can provide six years of carbon storage (or much, much more if buried in a box in my basement). Weyerhaeuser suggests this is better than letting trees rot or burn in the forest.

But wood houses don’t last forever, and many wood products end up decomposing in landfills, fomenting methane emissions that warm the planet even faster. Logging overall pumps far more carbon into the atmosphere than letting trees die or burn in otherwise healthy, old-growth forests. One recent study found that tree-harvesting can emit anywhere from two to eight times as much carbon as a fire.

And Weyerhaeuser’s plantations aren’t as biologically diverse or long-lasting as old-growth forests, reducing their carbon-storing ability. Even a 50-year-old plantation absorbs just 38 percent of the carbon of an untouched forest, according to one study. As my colleague Lara Williams notes, a thriving biome of many plant and animal species working together is far better at storing carbon than, say, a massive tract of young pine trees.

If we assume Weyerhaeuser’s method of assessing its carbon impact makes sense, that doesn’t change the fact that the company wants green credit mostly for forestry it would be doing anyway. It has been planting and chopping down trees for more than 100 years, after all. A frequent criticism of carbon offsets is that they don’t really add anything to the world’s carbon-reducing power, making them a cheap way for the companies that buy them to continue polluting.

Forest-based offsets have come under particular scrutiny lately, with report after report suggesting they don’t mop up nearly as much carbon as they claim. The offset industry overall has taken so much heat that many companies are already starting to abandon it.

Weyerhaeuser says it understands that its carbon reductions needs to go beyond “business as usual” levels. “[W]e believe the market is evolving toward higher-quality credits that demonstrate real, additional carbon absorbed and stored in project areas,” the company said in response to my query about its efforts.

Avoiding a future of runaway global warming will require far more aggressive efforts to reduce carbon emissions. Weyerhaeuser, for example, could do more for the planet by continuing to embrace renewable energy and pursue sustainable, biologically diverse forestry; not just replanting, but rewilding. Suffice to say that offsets may be a profit center for now, but they will do little to absolve any of us of our climate sins.

Mark Gongloff is a Bloomberg Opinion editor and columnist covering climate change. A former managing editor of Fortune.com, he ran the HuffPost’s business and technology coverage and was a reporter and editor for the Wall Street Journal.