The authors of the research, scientists from the University of Wisconsin-Madison, Kansas State University, the University of Kentucky and the University of California, assessed the environmental impact of a programme on introducing the standards of renewable fuel (Renewable Fuel Standard – RFS), in effect in the United States since 2006.
The programme provides annual norms for obligatory use of different types of biofuel, including from cellulose and biomass. In 2006, that norm stood at 4 million gallons, while in 2022, it increased to 36 million gallons. By way of comparison: consumption of petrol in the United States in 2022 is to total 138 million gallons, according to the Energy Information Administration (EIA) of the U.S. Department of Energy.
While conducting the research, the scientists analysed not only CO2 emissions from burning bioethanol (one of the types of renewable fuel), but also emissions observed throughout the value-added chain, including the harvest of plant crops. According to the outcome, as a result of the RFS programme, the price of corn in the United States rose by 30 % in the period from 2008-2016 and the price of various grains by 20 %. The planting area for corn crops rose by 8.7 %, while the increase for grain crops overall was 2.4 %.
There was an increase in the use of fertiliser (ranging from 3 % to 8 %, depending on the type of grain) and of other products which negatively affected water quality (from 3 % to 5%). Other increases in emissions directly attributable to agriculture were also noted.
As a result, according to the researchers’ calculations, the production cycle of bioethanol contained 24 % more unit emissions than was the case for standard petrol.
The transition to the production of biofuels is becoming more popular among oil and gas companies. Spain’s Repsol, in presenting a new long-term strategy last year, announced its intention to boost capacities in producing biofuels from the current 0.7 million tonnes to 1.3 million tonnes in 2025 and more than 2 million tonnes in 2030. ExxonMobil plans to proceed with production of renewable diesel through its Canadian affiliate, Imperial Oil.
The share of the transport sector in world-wide CO2 emissions totalled 19 % in 2019 – three-quarters of that was attributable to cars and light trucks, according to calculations published by McKinsey. The share of agriculture did not exceed 1 %.
