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. 

Forest degradation 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 routinely sources wood from the clearcutting of highly biodiverse coastal, according to its own website, uses large quantities of hardwood from the Southeastern USA to produce its pellets. Those forests are at the heart of a global biodiversity hotspot, the North American Coastal Plain. US NGOs Dogwood Alliance and Natural Resources Defense Council have been investigating the practices and impacts of Enviva's pellet production since 2014. 

Graanul Invest is Europe's biggest pellet producer. It is an Estonian company with pellet plants in all three Baltic States. A report by Estonian Fund for Nature and Latvian Ornithological Society published in December 2020 illustrates how the large demand for wood pellets for exports is increasing pressures on forests in both countries, where the intensity of logging is already at or near record levels. Intensive logging is resulting in serious harm to biodiversity, with the number of forest birds falling by around 50,000 breeding pairs a year in Estonia. High logging volumes are causing forests to sequester less and less carbon, as shown in reports by the countries' governments. The report further shows that a Graanul Invest affiliate has been clearcutting forest even inside a Natura 2000 site, which should be protected under EU law.

Graanul Invest also routinely sources whole logs from forest clearcuts, as confirmed most recently by investigative reporters in late 2020 and, previously, in a report by Biofuelwatch following visits to Estonia in 2018 and 2019 and looked at three Graanul pellet plants and logging practices. 

Pinnacle Pellets is based in British Columbia and has been found to also use significant amounts of whole trees for making pellets according to the NGO Stand.earth. According to the NGO's report, Pinnacle Pellets' Meadowbank mills in B.C. is located close to old-growth forest which is prime caribou habitat.