Dirtier than Coal?

Kenneth Richter

19 November 2012

So, the joint Friends of the Earth, RSPB and Greenpeace report "Dirtier than coal?" - about the burning of trees in power stations - has been getting quite a bit of attention, including reports on the BBC News, the Today Programme, BBC World service, Radio 4's Material World, The Times and the Telegraph.  

What is it actually about?

The report is based on research commissioned and published by the Department for Energy and Climate Change about the climate impacts of burning trees for energy in power stations.
The (now outdated) theory was that when you cut down and burn trees then this is carbon-neutral because the carbon released into the atmosphere when burning a tree is eventually re-absorbed into a new tree growing in its place.

Unfortunately the reality is that it can take decades or longer for the carbon to be reabsorbed from the atmosphere. This creates a carbon debt.

The report found that while over a 100-year time-scale burning a tree is better for the climate than burning coal, over 40 years it is 50% worse than burning coal and over 20 years even 80% worse. Obviously one thing we don't have in the fight against climate change is long time scales.    

Our demand to DECC is to account for carbon debt  emissions and to stop subsidies for burning whole trees under the Renewables Obligation.

What happened next?

The industry didn't like the report and has been issuing rapid responses. These responses have taken a number of different approaches:

• One approach has been to muddy the waters, claiming that our report disputes the role of all forms of biomass in reducing emissions:
  This is not the case: the report looks very specifically at the impacts of burning whole trees for power.  
• Another approach has been to out-right deny that carbon debt exists:
  This is in conflict with DECC's analysis that found, consistent with a wide range of peer-reviewed literature, that burning whole trees increases greenhouse gas emissions. 
  The European Environment Agency issued a strong warning about the current carbon accounting error last year.  
  The US state of Massachusetts has already implemented legislation that addresses carbon debt from trees used in power generation.
• Some argue that DECC already has legislation in place that accounts for the emissions from biomass: 
  DECC does have rules in place that account for the greenhouse gas emissions involved with the energy used in the processing and transport of wood.  But those emissions are small. 
  What DECC does not have in place are rules to account for the loss of carbon due to the harvest of the trees.  DECC's bioenergy strategy explicitly states that such carbon should be counted, but DECC's present rules do not do so.
• Others in the industry have taken a different approach: acknowledging the impact of carbon debt but arguing that the UK power stations do not burn trees, only wood waste and forestry residues. 
  However this has been disproven by a new report by the Dogwood alliance, an organisation that works to protect forests in Southern Eastern US, which provides evidence that whole trees are in fact used by US manufactures of wood pellets for export to the UK.  

What has been lost in this hoo-ha is what is actually needed in our battle against climate change: Renewable energy that delivers real climate benefits. Which is why we are asking DECC to stop subsidising the burning of whole trees for power and instead support clean British energy.

You can read our report here.