European Union (EU) rules intended to reduce power plant reliance on fossil fuels are threatening significant areas of ecologically important hardwood forests across the southeastern US, and will do little to mitigate carbon emissions, according to a new report.

The report, produced by the Natural Resources Defense Council (NRDC) in collaboration with the Conservation Biology Institute, detailed a 150% increase in wood pellet exports (pdf) from the US during the past three years. Most are bound for Europe, where power companies are replacing coal and other fossil fuels with wood-based biofuels in order to benefit from EU incentives on renewable energy sources.

Debbie Hammel, senior resource specialist for NRDC’s Land and Wildlife Program, said that the EU has few safeguards to ensure that wood pellet biofuel comes from plantation-grown trees and wood remnants, rather than wood harvested from mature forests. That calls into serious question EU claims of carbon-neutral biomass fuels, she said.

“When you burn wood pellets you are immediately and instantaneously releasing carbon into the atmosphere,” said Hammel. “And there’s very little certainty that those forests will continue to grow over the long term.”

The report detailed geographic information system mapping (GIS) conducted in bottomland hardwood forests and wetlands in Virginia, North Carolina, Alabama, Mississippi and southeastern Georgia – areas that have experienced rapid expansion of wood pellet manufacturing since 2012. It identified parts of Louisiana as another emerging zone of concern.

The report warned that 24m acres of unprotected forest lands across the southeastern US are at risk, largely from European biomass operations. It predicts that wood pellet manufacturing throughout the region could increase twelve-fold by 2020.

As new pellet mills come online, the report said, the areas they target for wood harvesting are likely to overlap with those of existing mills, creating what the report referred to as wood sourcing hotspots and intensifying potential ecosystem damage.

Southeastern forests in the US have long been under threat from urban sprawl, agriculture and the pulp and paper industries. Today, they are also increasingly under threat from rising sea levels. With the rise of the wood pellet industry, the risks to these ecosystems, which include hundreds of endangered, imperiled and threatened species, could escalate dramatically, warned James Strittholt, president of the Conservation Biology Institute.

“It makes perfect sense that we work toward a non-fossil fuel energy source – no argument there – but the issue is the alternatives we pick are not always benign and we need to be thoughtful about that,” Strittholt said. “Just because it’s trees and not fossil fuel, it shouldn’t be everything goes, because everything will indeed go if there aren’t some kinds of controls.”

Strittholt observed that development of new wood pellet facilities is moving much faster than regulators can respond. He noted that some of the forest lands identified just last year in the mapping project as future harvest sites have already been affected.

“From the looks of the data we’re seeing … there’s an economic opportunity, there’s a market, so the corporate response can be quite rapid compared with any safeguarding mechanisms already in place,” he said.

Pellet manufacturer Enviva and British utility Drax Power are leaders in the region’s expanding biomass industry. In an email, Enviva’s vice president of communications, Kent Jenkins Jr, countered some of the report findings. He said the majority of wood used by Enviva’s production plants in Virginia and North Carolina comes from upland forest and mixed stands rather than mature bottomland hardwood.

“Regardless of the source, we use only leftover and low-grade wood that undergoes a rigorous sustainability assessment, certified by independent third parties,” Jenkins said.

Hammel dismissed wood pellet makers’ sustainability standards as “extraordinarily insufficient”. She said companies need to be more transparent about the source of wood used in their products and decrease reliance on mature forests that might take hundreds of years to regrow, thereby undermining any potential emission mitigation.

The NRDC is urging the EU to enact more stringent standards for biomass carbon accounting. The organization is also asking the EU to cap the amount of biofuel permitted in power generation so the demand doesn’t outstrip the supply of actual low-carbon biomass like sawdust and remnant wood.

“These forests are our best defense against climate change,” Hammel said. “They soak up carbon and provide habitat for critically endangered species. EU policymakers need to do the right thing and protect forests and climate.”