biomass use and air quality

Biomass use and air quality in California; a balancing act - A blog by Jack Bailey-Bale

Climate change and air quality are certainly not matters to be sniffed at. They are major environmental issues we face as a global community – and California is no exception. This has been reflected in the agreement of international conventions, down to state level legislation, of which California has led the pack.

As we look to reduce greenhouse gas emissions from the energy sector, agriculture, industry, transport, building sector and other land use changes, it is critical to avoid unintentional degradation of already concerning air quality. Rapid uptake of renewable energy sources, such as biomass, is certainly an essential step for the future of the planet and life as we know it – but it is not completely clean. Biomass combustion releases greenhouse gases, as well as criteria pollutants that are damaging to human health. Criteria pollutants include the likes of: carbon monoxide, nitrogen dioxide and particulate matter, which are globally responsible for premature deaths and increases in asthma attacks. It is therefore crucial that policy surrounding the production and use of biomass considers climate and criteria pollution, in order to achieve improvements for both.

With the aim of informing policy on the best use of California’s biomass to meet air quality and climate goals, Peter Freer-Smith and Gail Taylor are leading a project with the California Air Resources Board (CARB). CARB was formed in 1967 as a merger of the Bureau of Air Sanitation and the California Motor Vehicle Pollution Control Board. That same year California was granted the ability to set its own, firmer, air quality standards due to the enactment of the Federal Air Quality Act. CARB is now responsible for producing a scoping plan detailing the state’s strategies to reduce criteria pollutant and greenhouse gas emissions.

The estimated biomass resource figures for California are substantial. The California Biomass Collaborative Project in 2007 assessed the available sustainable biomass to be 32 million bone dry tons per year. This was projected to rise to an available 40 million bone dry tons per year by 2020. The main sources of biomass originate from forestry, agriculture and municipal waste. Additionally, we shall also be taking into account food processing residues and waste water. Of course, the cultivation of biomass is not the sole producer of harmful criteria and climate pollutants – it is coupled with the use of the biomass. Depending on the source of biomass, there are multiple utilisation pathways. For this study, we will be considering the following uses:


To accurately evaluate the impact of biomass pathways on California’s air quality, we shall synthesise Californian relevant literature linking biomass feedstocks and utilisation pathways to air quality. To ensure a thorough search of the research field, a systematic approach will be employed, combining key search terms to maximise capture. An initial screening phase will be followed by full text appraisal, leaving only literature that is informative to the posed research question.

As governments and research institutions are declaring a climate emergency, there is growing concern surrounding the quality of the air we breathe. The importance to reduce greenhouse gas emissions is only compounded by the fact that climate change is linked with increased frequency of extreme climatic events, which can vastly reduce air quality. California only has to think back to November 2018 to recall the tragic forest fires that decimated communities and habitats, as well as harming thousands of people’s health due to prevailing winds distributing criteria pollutants.

Developing insightful policy with criteria and climate pollution goals as priorities for the best use of biomass in California will be integral for a cleaner, healthier and sustainable future.


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