In a cavernous theater lit up with the inexperienced shapes of camels and palms at COP28 in Dubai, ecologist Thomas Crowther, former chief scientific adviser for the United Nations’ Trillion Trees Campaign, was doing one thing he by no means would have anticipated a few years in the past: begging environmental ministers to cease planting so many timber.
Mass plantations aren’t the environmental resolution they’re purported to be, Crowther argued when he took the ground on December 9 for one of many summit’s “Nature Day” occasions. The potential of newly created forests to draw down carbon is commonly overstated. They might be dangerous to biodiversity. Above all, they’re actually damaging when used, as they typically are, as avoidance offsets— “as an excuse to avoid cutting emissions,” Crowther stated.
The reputation of planting new timber is a drawback—no less than partly—of Crowther’s personal making. In 2019, his lab at ETH Zurich discovered that the Earth had room for an extra 1.2 trillion timber, which, the lab’s analysis prompt, might suck down as a lot as two-thirds of the carbon that people have traditionally emitted into the ambiance. “This highlights global tree restoration as our most effective climate change solution to date,” the examine stated. Crowther subsequently gave dozens of interviews to that impact.
This seemingly straightforward local weather resolution sparked a tree-planting craze by corporations and leaders keen to burnish their inexperienced credentials with out really slicing their emissions, from Shell to Donald Trump. It additionally provoked a squall of criticism from scientists, who argued that the Crowther examine had vastly overestimated the land appropriate for forest restoration and the quantity of carbon it might draw down. (The examine authors later corrected the paper to say tree restoration was solely “one of the most effective” options, and will suck down at most one-third of the atmospheric carbon, with giant uncertainties.)
Crowther, who says his message was misinterpreted, put out a extra nuanced paper final month, which exhibits that preserving current forests can have a better local weather influence than planting timber. He then introduced the outcomes to COP28 to “kill greenwashing” of the sort that his earlier examine appeared to encourage—that’s, utilizing unreliable proof on the advantages of planting timber as an excuse to carry on emitting carbon.
“Killing greenwashing doesn’t mean stop investing in nature,” he says. “It means doing it right. It means distributing wealth to the Indigenous populations and farmers and communities who are living with biodiversity.”
The query is, did international locations at COP28 get the purpose? A couple of minutes after Crowther spoke, Mariam Almheiri, the local weather change and setting minister for the host nation, the United Arab Emirates, addressed the theater. She praised his presentation, then started boasting that the UAE was virtually midway to planting 100 million mangroves by 2030. At the identical time, the UAE’s state oil agency, ADNOC (whose CEO was the president of COP28), has the most important future growth plans of any oil firm on the earth—an growth incompatible with assembly the Paris Agreement’s targets, which sought to restrict international warming to 1.5 levels Celsius. That’s greenwashing, in accordance to Kate Dooley, a researcher on the University of Melbourne who has studied nature restoration’s carbon drawdown. “Carbon storage in nature is temporary and therefore is not equivalent to permanent fossil fuel emissions,” Dooley says.