Can we achieve net-zero burning wood biomass?

 

It sounds crazy but, until about a week ago, I had no idea the European Union and the UK Government classes the burning of wood as a low carbon energy source. This logic is based on the fact the carbon released into the atmosphere when burning wood biomass was absorbed out of the atmosphere as the trees grew and, newly planted replacement saplings will repeat the carbon absorption cycle again. In 2020, 12.6% of the UK's electricity production came from burning biomass contributing towards reducing coal burning for power generation to just 1.8% in 2020 from 28.2% in 2010. That is an astonishing achievement in a decade. Something which isn't celebrated enough.

 

At the same time, we must remember how far we still have to go to decarbonise. Biomass is a bit of a double edged sword as well. Although it is ultimately renewable, there is a time lag we must remember to appreciate. If you burn a tree today, all that carbon goes into the atmosphere today. However, for replanted replacement trees to reabsorb that carbon out of the atmosphere back into more biomass takes over 100 years. Over a century! We don't have that much time.

The UK Government's commitment to reach net-zero by 2050 is not an arbitrary target date. The Glasgow Pact of COP26 set out the World's commitment to take actions to achieve the Paris Agreement's goal of maintaining greenhouse gas emissions below 2% of pre-industrial levels, preferably staying below 1.5%. Fulfilling this pledge limits the likelihood of experiencing climate change severe enough to trigger agricultural collapse and the end of humanity as we know it. 

The problem is, greenhouse gas emissions already sit at approximately 1.1% above pre-industrial levels. This means the UK's net-zero by 2050 target is cutting it close to the wire. The World only has a matter of years rather than even decades to significantly curb our emissions. Burning wood now in anticipation of that carbon getting reabsorbed over the next century just isn't going to cut it. A grim truth.

 

Thankfully, there is aknowledgement of this issue, contrary to what some would have you believe. The UK Government, in 2021, wrote the preliminary Biomass Policy Statement, which explains the need to use and incentivise the adoption of technologies to capture and store carbon produced from the burning of biomass. This practice possesses the less than catchy acronym of BECCS, Bioenergy with Carbon Capture and Storage. By capturing and storing carbon from biomass burning you can create carbon negative power generation. Trees absorb carbon from the atmosphere as they grow; the resulting carbon is captured as the wood biomass is burned to produce power; that stable captured carbon is stored in the soil or underground; newly planted trees absorb carbon from the atmosphere again; a maintainable carbon negative system of power generation is achieved.

Worryingly, such carbon capture technologies are still in their infancy. To date, there are only six carbon capture systems in operation in the World... The ones that do exist are expensive making them economically unviable. The UK Government is working to change this. Between August and October of this year (2022), they held a consultation to propose "a business model to incentivise deployment of power bioenergy and carbon capture (BECCS) within the UK". In their Net Zero Strategy, the Government has gone as far as stating an ambition for this country to deploy technologies to capture at least five million tonnes of carbon per year by 2030.

I will follow the results of this consultation with great interest and hopeful optimism.