In general, biomass power stations cause similar levels of air pollution to coal power stations of the same capacity. Using biomass as a fuel produces air pollution in the form of carbon monoxide, carbon dioxide, NOx (nitrogen oxides), VOCs (volatile organic compounds), particulates and other pollutants at levels above those from traditional fuel sources such as coal or natural gas in some cases (such as with indoor heating and cooking).

Apart from these impacts on people in the Teesside area, communities in the southern US by Enviva’s pellet plants will also be affected. Dogwood Alliance has worked with some of those communities to document the impacts from noise, traffic, pollution and, particularly worryingly, wood dust. Long-term wood dust exposure is carcinogenic according to the World Health Organisation, and it is also linked to allergic and non-allergic respiratory and nasal problems.

Forests play a vital role in maintaining clean water on which communities depend. They filter and store freshwater and they help to regulate regional rainfall cycles. This is particularly vital in a region such as the southern US, which is already seriously affected by extreme rainfall events (droughts and floods) that are exacerbated by climate change. Increased pressure on the remaining wetland forests of the region will thus put the local population at greater risk from the further disruption of the water cycle.

The UK is already burning significantly more wood in power stations annually than the country produces in total every year. MGT Power will source around 1 million tonnes of pellets (equivalent to 2 million tonnes of green wood) from Enviva, who are the largest US pellet producer and who are rapidly expanding their pellet capacity across southern US. US conservation NGOs, including Dogwood Alliance and Natural Resources Defense Council, have carried out detailed investigations of some of Enviva’s pellet plants. They have found that a high proportion of Enviva’s pellets is made from hardwood, which in the region is not found on tree plantations but only in biodiverse forests. By following logging trucks to the forest and back to an Enviva pellet plant, they have documented that whole trees clearcut in wetland forests are being turned into pellets which are then shipped to Europe, especially to the UK.

Coastal wetland forests in the southern US are one of the world’s most biodiverse temperate forest and freshwater ecosystems. They form part of the North American Coastal Plain biodiversity hotspot, which is home to 1,816 endemic species of vascular plants, 138 endemic species of freshwater fish, 57 endemic species of amphibians, as well as many endangered bird, reptile and mammal species. Enviva misleadingly describes whole trees from clearcut forests as ‘residues’ or ‘thinnings’, despite clear evidence to the contrary.