The potential of climate plantations is overestimated
Climate plantations are seen as an important factor in achieving the goals of the Paris Agreement. Particularly fast-growing plants, which draw CO2 from the atmosphere, are burnt in bio-power stations, and in the process "Bioenergy with Carbon Capture and Storage" the greenhouse gas is captured and then stored. But the potential of this process is limited said researchers from Mercator Research Institute on Global Commons and Climate Change (MCC) in February 2021.
One in two scientific scenarios about the future that take into account the temperature targets of the Paris world climate agreement, contain one glaring element: they point out that in 2100, at least six million square kilometres will be covered with climate plantations, equivalent to two-thirds of the territory of the USA. According to the researchers this scale is unrealistic and misleading.
Land use for growing bioenergy crops should not be increased at all
"Under the current circumstances, the area of land used for growing bioenergy crops, about 500,000 square kilometres worldwide, should not be increased at all”, says Felix Creutzig, head of the MCC working group Land Use, Infrastructure and Transport. As Coordinating Lead Author, he is in charge of the chapter on demand, services and social aspects of climate mitigation in the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), expected in 2021 or 2022.
For their analyses the researchers evaluated the database of the Integrated Assessment Modeling Consortium (IAMC) of the International Institute for Applied Systems Analysis (IIASA) research institute, and found that only a fraction of the scientific climate scenarios use no more than the current land area for bioenergy crops: in all, only six out of the total of 132 “Integrated Assessment Models" that derive a future consistent with the Paris Agreement and explicitly present land use.
Climate protection of this kind could be even worse for nature than no climate protection at all
To justify that additional climate plantations would not really make the world more sustainable, the scientist highlight two IPCC special reports (the report on the 1.5-degree target in 2018 and the one on land use in 2019) and numerous other scientific studies.
Scaling up bioenergy with carbon capture and storage would firstly endanger biodiversity, the researchers warn, emphasising that climate protection of this kind would be even worse for nature than no climate protection at all. They explain that the populations of mammals, amphibians, reptiles and fish worldwide have already declined during the last centuries. This aspect should be given greater consideration in the IPCC, as should, secondly, risks to the livelihoods of indigenous peoples. Thirdly, the scenario models pay too little attention to the problem of tipping points: for example, if the world keeps on emitting CO2, causing temperatures to rise and relying on large-scale carbon capture in the second half of the century, methane might escape from thawed permafrost in Siberia, and exacerbate the climate crisis.
"The fact that the bioenergy method in reality does not have much potential does not spell disaster for climate change mitigation," emphasises MCC researcher Creutzig. "After all, there are forms of carbon removal which are much less land-intensive, such as direct air capture with air filter systems. Above all, the most important thing is to reduce emissions immediately. That means decarbonising the economy, even reducing energy consumption where possible, and incentivising climate-friendly behavioural changes, for example in nutrition."
Read more at MCC website
Creutzig, F., Erb, K., Haberl, H., Hof, C., Hunsberger, C., Roe, S., 2021, Considering sustainability thresholds for BECCS in IPCC and biodiversity assessments, Global Change Biology Bioenergy