A study by the Center for Atmospheric and Oceanic Sciences in the Indian Institute of Science has revealed that reducing fossil fuel emissions might have greater climate benefits than afforestation.
The study, “A comparison of the climate and carbon cycle effects of carbon removal by afforestation and an equivalent reduction in fossil fuel emissions” was conducted by Koramanghat Unnikrishnan Jayakrishnan and Govindasamy Bala at the Centre for Atmospheric and Oceanic Sciences.
The duo in this paper compared the climate and carbon cycle consequences of carbon removal by afforestation, and an equivalent fossil fuel emission reduction using simulations from an intermediate complexity Earth system model.
“We performed two major sets of idealised simulations in which fossil fuel emissions follow extended Shared Socioeconomic Pathway (SSP) scenarios (SSP2-4.5, 3-7.0, and 5-8.5), and equal amounts of carbon are removed by afforestation in one set and by a reduction in fossil fuel emissions in another set,” states the abstract paper of the study.
How systems compare
It added that their simulations show that the climate is cooler by 0.36, 0.47, and 0.42 ∘C in the long term (2471 to 2500) in the case of reduced fossil fuel emissions compared to the case with afforestation when the emissions follow the SSP2-4.5, SSP3-7.0, and SSP5-8.5 scenarios, respectively.
“This disparity arises because afforestation, while effective at carbon removal, also introduces biophysical changes on the Earth’s surface, such as decreased reflectivity for sunlight and increased evapotranspiration, which together partly offset the cooling effect from carbon removal. In contrast, reducing fossil fuel emissions alone focuses on just preventing carbon dioxide release from fossil fuels, thereby reducing greenhouse gas concentrations without directly altering the land cover or vegetation,” IISc said.
The study further states that in terms of climate benefits, reducing fossil fuel emissions could be relatively more beneficial than afforestation for the same amount of carbon removed from the atmosphere. “However, a robust understanding of the processes that govern the biophysical effects of afforestation should be improved before considering our results for climate policy,” it said.
