Impacts from air pollution: Production of wood pellets for biomass is associated with air pollution and wood dust pollution. Long-term exposure to wood dust is linked to allergic and non-allergic respiratory and nasal disease and with dermatitis as well as two rare cancers. Studies have focussed on occupational exposure, however people living close to pellet plants can be exposed to significant levels of wood dust over long periods. Poor wood dust management has been observed and reported in relation to plants owned by Graanul Invest, communities next to Enviva plants have complained of dust and noise. Pinnacle Pellets has been criticized for failing to control wood dust, and, furthermore, they have had several explosions and fires at plants, resulting in injuries and even deaths of workers.

Climate impacts: Biomass combustion in coal-fired power stations emits even more CO2 upfront than burning coal (per unit of energy), accelerating climate change. Arguments that new trees will reabsorb the carbon emitted by burning wood pellets take no account of the long period of time before new trees mature, and the even longer period of time before forests and forest (including soil) carbon recover from the impacts of logging (presuming climate change and other environmental pressures don’t prevent this from happening altogether). Nor do they take account of the foregone sequestration of carbon by mature forests had they not been logged, nor of the permanent loss of carbon when forests are subsequently replaced with monoculture tree plantations. Hundreds of scientists have pointed out that burning wood from logged trees cannot be compatible with the need to limit global warming to 1.5 degrees. 

Deforestation impacts: The vast majority of the wood pellets are sourced from natural forests, which are being destroyed in the name of sustainability, whereas keeping them standing is crucial to mitigate the impacts of climate change since they are vital carbon sinks.

RWE has supply agreements with the world’s three biggest wood pellet producers, Enviva, Graanul Invest, and Pinnacle Pellets. Enviva, according to its own website, uses large quantities of hardwood from the Southeastern USA to produce its pellets. In that region, hardwood is only found in forests which are at the heart of a global biodiversity hotspot, the North American Coastal Plain. On the plantations, only softwood is grown. US NGOs Dogwood Alliance and Natural Resources Defense Council have investigated the practices and impacts of pellet production during five consecutive years since 2014. Their investigations have shown how Enviva routinely sources wood from the clearcutting of highly biodiverse, carbon-rich coastal hardwood forests. 

Graanul Invest is Europe's biggest pellet producer. It is an Estonian company with pellet plants in all three Baltic States. Biofuelwatch visited Estonia in 2018 and 2019 and looked at three Graanul pellet plants and logging practices. Its research showed that Graanul, like Enviva, relies significantly on whole trees as the source of its wood pellets. Clearcutting is also the prevalent logging method in Estonia, where logging rates are far beyond what can be considered sustainable and are harmful to biodiversity as well as to the climate. Almost all of Estonia’s forests are secondary forests, with trees cut down now which had been growing since the start of the Soviet occupation in the 1940s and which are an important habitat for wildlife such as the flying squirrel and the black stork. Remnants of old growth forests remain, and even those are not safe from logging, including clearcutting. Estonia has no mature tree plantations.

Pinnacle Pellets is based in British Columbia and has been found to also use significant amounts of whole trees for making pellets. NGO investigations are still in the early stages, but clearcutting of old growth forests is rampant in British Columbia, including in areas surrounding Pinnacle Pellet plants.