The findings of a study undertaken by the University of Limerick, Bangor University, and Feedback Global demonstrates use of biogas should be carefully constrained to undertake more effective climate solutions such as solar energy generation, waste prevention, and afforestation. This is to meet the challenging greenhouse gas emission target of ‘net zero’ set for 2050.
Earlier studies for the use of biogas have placed standard of environmental performance of anaerobic digestion against current leading technologies, stated the co-author of the study. The widely promoted green technology for biogas requires a more solid evidence-base for strategic sustainable investment, both today and in future contexts. This is because green technologies are likely to predominate the path toward net zero greenhouse gas emissions.
While biogas is currently a much cleaner transport fuel than diesel or petrol, rapid electrification of transport and development of green hydrogen fuel offers greater emission savings and could nullify the benefit of using biogas as a transport fuel in the coming decades.
Meanwhile, combustion of biogas on a large scale for generation of electrical energy or industrial heat generation could be its best use for GHG alleviation in future if bioenergy carbon capture and storage is deployed. The study provides a prototype of a potential ‘sustainable niche’ for anaerobic digestion in a context where food waste as well as dairy and meat consumption are halved, with anaerobic digestion facilities processing the remaining unpreventable food waste and manures. The sustainable niche prevents inefficient use of purpose-grown crops, and is based on ambitious policy action to prioritize food waste prevention.
The climate advantages of anaerobic digestion will decline as cleaner technologies predominate in the transition toward target of net zero greenhouse gas emissions.