by Judith Curry
More wood being burnt from British woods than since industrial revolution. – David Rose
While I’m in the UK, I thought it would be appropriate to focus on a UK environmental issue, and I was particularly struck by this recent article by David Rose on biomass burning for energy in the UK. The article begins:
One gloomy day in March 2012, Pip Pountney, recently retired from Warwick University, went for a walk in Ryton Wood near Coventry with Ann Wilson, a former textile chemist. Ryton’s 216 acres are described by its owners, the Warwickshire Wildlife Trust, as ‘one of the largest semi-natural ancient woodlands in Warwickshire’. A Site of Special Scientific Interest, it has long been famous for its bluebells, which flourished every spring beneath a canopy of English oaks. But what ex-teacher Pountney and Wilson saw looked to them like utter desolation. They came across a stand where about 50 mature oaks, some 300 years old, had been felled the previous winter. Their trunks lay in ragged piles, some sawn into roundels.
The oaks’ fate, the Trust has confirmed, was to be burnt: as ‘sustainable’ heating fuel in log-burning stoves – a market which is expanding rapidly. According to trade group HETUS, almost 200,000 such stoves are installed every year – a five-fold increase since 2007.
Logs, however, feed only a part of Britain’s expanding appetite for ‘green’ wood-sourced energy. Adding to demand is the even faster-growing market for heating and hot-water systems fuelled by wood chips and pellets – which is heavily subsidised by taxpayers.
The Forestry Commission and the biomass industry’s lobby group, the Woodland Heat Association, insist this policy is justified on environmental grounds. They say the new ‘biomass’ energy market can improve the quality of forests, by creating new financial incentives to ‘manage’ woods that have been neglected and allowed to run wild.
However, other experts fear that in some forests, the consequences will be disastrous. Oxford University ecologist Clive Hambler said: ‘Subsidising biomass is one of the most counter-productive policies ever invented, and about the most bizarre thing you could possibly do to counter climate change.’
In his view, felling British hard wood forests in order to burn them is harming biodiversity, destroying habitats, and may well increase emissions. He said: ‘Big, hardwood trees are enormous carbon sinks, and take hundreds of years to be replaced.’
Dr Mark Fisher, research fellow at the Wildland Research Institute at Leeds University, agreed, saying: ‘Forests are being butchered in the service of an ideology. This new industry incentivises devastation, and no one is looking at the long-term consequences for our woods.’
An interesting post from Unearthed address the debate over the carbon neutrality of burning wood for energy. Excerpts:
Some people may regard burning wood chips as carbon neutral because they think the carbon released from burning wood chips can be offset, compared to burning fossil fuels. According to the calculator’s user guide, the previous versions of the calculator regarded biomass as carbon neutral. When trees die, they release carbon into the atmosphere. As other trees grow, the carbon will be recaptured by photosynthesis. Thus, the total amount of carbon in the cycle doesn’t increase.
What’s more, according the guide, the carbon released from burning fossil fuels has been kept in the ground for millions of years, whereas the carbon emitted from burning wood chips is adding only a little carbon to what already exists in the cycle. So when fossil fuels are burned, much carbon is created without enough plants or trees to offset it. Wood, however, can be regrown.
Trees are about half carbon, and when they are burned, the carbon is released into that atmosphere in the form of carbon dioxide. Whether the carbon can be offset by regrowth of trees depends on many factors, such as type of energy produced, types of wood used and how much wood that is harvested, and so on.
One of the major concerns is that the regrowth of trees is not guaranteed and it takes time. Based on the latest scientific studies from around the country, the period of time for recapturing carbon can be 35 to more than 100 years.
An article in the Telegraph Are wood chips really worse than burning coal? states:
Some campaigners believe that using apparently environmentally friendly wood can be three times worse for the climate
Impact on human health
Last February, the American Chemical Society issued a press release on Understanding air pollution from biomass burners used for heating. Excerpts:
Aki Kortelainen and colleagues note that in Europe, burning wood for heat is one of the biggest sources of fine particulate emissions, contributing about the same amount of these tiny bits of pollution to the air as vehicles on a busy street. All totaled, these emissions — which have been linked to irregular heartbeats, breathing problems and nonfatal heart attacks — are associated with 350,000 premature deaths every year across Europe. In the U.S., the Centers for Disease Control and Prevention estimates that a 10 percent reduction in these particles of dust, soot and smoke could save at least 13,000 lives annually. With the rise in wood chip burners, Kortelainen’s team wanted to better understand the technology’s potential impacts on pollution and health.
The researchers measured fine particulate emissions from a wood-chip burner and found that emissions varied as the fuel went through different stages of combustion. They conclude that emissions can be reduced if burning efficiency can be maintained at a high level. The finding, they say, could help the industry design units that are less polluting and less harmful to people.
All this looks to me like the ‘cure’ is worse than the ‘disease’. The putative diseases are environmental pollution and climate change and expensive or unavailable energy. The wood burning ‘cure’ exacerbates air quality problem, increases CO2 in the atmosphere, and damages ecosystems if whole trees are cut down.
“Renewable” energy, rather than fossil fuels, is not useful if it makes air quality worse, adds CO2 to the atmosphere, and damages ecosystems.
Can anyone figure out a defense of this practice (apart from UK homeowners being unable to afford grid energy prices as a result of, well, renewables)?