Committee on Climate Change

Bioenergy refers to combusting solid, liquid or gas fuels made from biomass feedstocks, which may or may not have undergone some form of conversion process. It is a type of renewable energy and can be based on a variety of feedstocks, including food crops (e.g. wheat, maize, soya or sugarcane) wood, straw, and manure.

Bioenergy currently provides a 2% share of total energy consumption in the UK, but according to our review, it will be difficult to meet the overall 2050 emissions target unless bioenergy can account for around 10% of energy by then.

Importance of a sustainable approach to bioenergy

The role of bioenergy in climate change mitigation is controversial and there are significant sustainability concerns associated with its use. These relate to:

• The emissions reductions that can be achieved through using it – It is difficult to account fully for all emissions resulting from the use of bioenergy and often some lifecycle emissions (e.g. relating to indirect land use change) are excluded – so higher emissions than accounted for may be produced.
  
  
• The sustainable supply of bioenergy - Population growth, coupled with increasing wealth, means that in the next decades there will be an increasing need for land to grow food. Growth of bioenergy feedstocks could risk displacing food production. In addition, there are wider environmental and social impacts associated with the use of bioenergy e.g. negative impacts on natural habitats and issues about land rights.

It is therefore important that in deciding how to support the use of bioenergy, the Government fully considers its wider environmental and social impacts.

Bioenergy review

In December 2011, the Committee published a review into bioenergy which assessed the role of bioenergy both globally and in the UK and considered how it might best be applied across the UK economy.The findings of the review will be considered by Government in the development of their new bioenergy strategy.

The review reached four main conclusions: 

1. The need for bioenergy versus its sustainable supply. It will be difficult to meet the overall 2050 emissions target unless bioenergy can account for around 10% of total primary energy (compared to the current 2%). However, it would be unsafe at present to assume any higher levels of bioenergy supply, and even the 10% level may require some trade-offs versus other desirable environmental and social objectives.
    
2. Lifecycle emissions. It is important that the role of bioenergy in low-carbon strategy reflects realistic estimates of total lifecycle emissions for different types of feedstock, including both direct and indirect land use change impacts. EU and UK regulatory approaches need to be strengthened to mitigate these risks.
    
3. Appropriate use of limited sustainable bioenergy supply in the long term. Given limits to the global supply of sustainable bioenergy, it is important that this is used in an optimal fashion. Our analysis shows that the appropriate use depends crucially on whether or not Carbon Capture and Storage (CCS) is an available technology:
   
   a)  If CCS is available, bioenergy should be used in applications with CCS, making it possible to achieve negative emissions. These applications could include power and/or heat generation, the production of hydrogen, and the production of biofuels for use in aviation and shipping.
   
   b) Without CCS, bioenergy use should be skewed towards heat generation in energy intensive industry, and to biofuels in aviation and shipping.
   
   c) The review also considered alternative uses for bioenergy feedstocks and found that using wood in construction should be a high priority, as it is a very efficient form of carbon capture.
    
4. Implications of bioenergy availability for overall carbon strategy. Policy should place a high priority on developing and demonstrating CCS technology. Government should incentivise other (non-bioenergy) decarbonisation options (e.g. energy efficiency, low-carbon power options, electric vehicles) and support research in areas where a potential for breakthroughs exists (e.g. new bioenergy technologies).

The review is supported by four technical papers which provide more detail about our analysis.