The United Kingdom imports over five million metric tons of wood pellets from the U.S., Canada, and Estonia only to burn them in the giant Drax power plant, converting them into electric power and carbon dioxide. It is considered carbon neutral because the trees soaked up carbon when they grew, and the trees that replace them will soak it all up again. This has always been controversial.

Now, in the runup to the UN Biodiversity Conference (COP 15) in Montreal, over 650 scientists wrote an open letter urging the end to burning forest biomass for energy “for the sake of nature and biodiversity.”

The pellet industry claims that pellets are made from “residuals,” in other words the scraps and the slash left over in the process of lumbering. The authors of the letter say this isn’t true and claim whole trees are being clearcut and fed into the chipper for pellets.

Stand.earth, a Canadian environmental organization, has also made this claim and backed it up with pictures.

Ben Parfitt, the policy analyst for the Canadian Centre for Policy Alternatives (CCPA), said last year: “The industry and government insist ‘residuals’ like wood waste from sawmills are used primarily to make wood pellets. But in fact, pellet companies are using logs from whole trees to feed straight into their mills. That’s bad news for our forests, rural towns, workers, and the climate alike.”

The authors of the letter are talking about forests all over the world that are sources of these pellets.

The letter doesn’t spend a lot of ink on the question of carbon emissions, although it does question whether Bioenergy with Carbon Capture and Storage (BECCS) as proposed by Drax and others, even works. Their bigger worry about BECCS is it would encourage even more planting of bioenergy crops. This “would diminish the land available for wildlife and natural ecosystems, and jeopardize global food security. Indeed, some projections estimate that worldwide use of BECCS to achieve net zero would require up to 1.2 billion hectares of land—the equivalent of about 80% of all current global cropland.”

The industry claims that BECCS is considered carbon neutral or even carbon negative by the Intergovernmental Panel on Climate Change (IPCC), but this is not the case, as noted by Sasha Stashwick of the NRDC:

Lloyd Alter

We have a carbon crisis now, and the atmosphere doesn’t care if the emissions come from trees or coal—they still count against the carbon budget. Planting a tree to suck it back up over the next 40 years won’t change that.

We have been arguing about whether burning wood is carbon neutral for years, but I have a simplistic view of the subject: A tree might have taken 40 years to store its carbon, but burning it in a power plant releases it all in a giant burp in seconds. We have a carbon crisis now, and the atmosphere doesn’t care if the emissions come from trees or coal—they still count against the carbon budget. Planting a tree to suck it back up over the next 40 years won’t change that.

But the signatories to the letter add another important issue that hasn’t been considered: its effect on ecosystems. The authors conclude, “The best thing for the climate and biodiversity is to leave forests standing—and biomass energy does the opposite.” Another very good reason to stop burning trees for electricity.