Could Australia Use Plants To Pull CO2 Out Of The Air And Store It Underground?

CREDIT: Greenfleet Australia

Australia is in dire straits when it comes to climate change. An obstinate government has been tenacious in the quest to perpetuate fossil fuel extraction while sidelining clean energy and climate change efforts. Meanwhile the country is experiencing extreme weather events on a regular basis, including droughts, heat waves, floods, and massive cyclones. With its already hot and dry climate, Australia is projected to be one of the most dramatically affected developed nations from climate change. With this in mind, the Climate Institute, a think tank focused on finding solutions to climate change, set out to determine if a controversial process called bio-energy with carbon capture and storage (BECSS) could help the country mitigate its emissions to meet ambitious climate goals.

BECCS involves burning biomass — trees, plants, crop materials, woodchips — to generate electricity or other forms of energy, then capturing the carbon that is released and pumping it underground in geological reservoirs. The technique, which is unproven at a large scale, was proposed as a possible means of mitigation in the latest Intergovernmental Panel on Climate Change (IPCC) report released over the weekend. The report both warns that avoiding 2 degrees Celsius in temperature increases by 2100 was nearly impossible without carbon-removal technologies and that the costs and risks widespread deployment of carbon dioxide removal technologies are uncertain. Proponents of the technique suggest that the process might be “negative emission” because it could reduce the total amount of carbon dioxide in the atmosphere, while opponents argue that it would require large amounts of land and ecosystem destruction and is based on the risky conclusion that we can indeed find an economic way to bury carbon dioxide in the ground as a large-scale endeavor.

The Climate Institute study, conducted by energy modelling firm Jacobs SKM, found that BECCS could play a significant role in meeting Australia’s climate goals. It determined that by 2050, BECSS has the potential to remove and displace up to 71.5 million tons of CO2 per year, about 1.5 times the current emissions of Australia’s transportation sector. The total from now to 2050 could be 860 million tons. Australia has a large agricultural economy and substantial geological storage areas, and the researchers state that this could be done without devoting any new land to bioenergy production but rather relying on food wastes, sustainable plantation forest biomass and crop residues. The study does not overlook the need for parallel efforts to mitigate emissions, and says that BECSS would be another effort alongside the need for renewable energy sources and gains in energy efficiency.

“Appropriately managed, BECCS has the potential to best remove and store large quantities of our carbon over geological timescales, while providing energy supply,” wrote John Connor, chief executive of The Climate Institute. “The challenge is to develop and deploy these capabilities as a support, not substitute, for urgent action in other renewables, energy efficiency and low carbon technologies:”

“There’s no silver bullet in the climate challenge … A big question remains over whether the level of bio-energy needed could be produced in a socially and ecologically sustainable manner. These risks don’t mean we shouldn’t consider the potential of BECCS or other carbon removal technologies, they mean we need to work out how to do it properly.”

The negative emissions argument goes that when biomass is used for power production, the carbon released back into the atmosphere is part of the natural cycle, making it carbon-neutral. Therefore if that carbon is captured instead and stored permanently underground, there would actually be a net removal of CO2 from the atmosphere. However some see this a being akin to a risky geoengineering techno-fix that when implemented would likely prove far more costly and unpredictable than anticipated.

“To do BECCS on a large scale you need vast areas to grow crops or trees,” Almuth Ernsting from Biofuelwatch told BBC. “What’s become clear with the evidence of biofuels is that such large programs result in massive ecosystem destruction which releases large amounts of carbon and these land conversions have significant impacts on people too.”

While climate change is a global dilemma, each country must pursue the options best suited for their environmental and economic conditions — In Australia, BECCS may fit the bill. And as the new IPCC report goes to great lengths to detail, that bill will only get larger the longer action is postponed, although it remains surprisingly affordable for the time being as ClimateProgress’ Joe Romm recently detailed.