AFP, published on Wednesday, April 13, 2022 at 11:23 PM
Faced with record inflation and to lower prices at the pump, US President Joe Biden this week announced the lifting of restrictions on E15, a fuel containing 15% ethanol, as well as investments in biofuels.
But experts who have studied the impact of ethanol on the environment are far from gratifying.
– What is ethanol? †
Ethanol is present in all fuels in different proportions.
The most commonly sold gasoline in the United States today contains approximately 10% ethanol (E10).
There are two types of ethanol: synthetic, derived from petroleum, and organic, bioethanol, made from wheat, sugar beets, or even corn, as is especially the case in the United States.
Cars built from 2001 can use E15, the US government says.
But the E15 is far from widely available. It is only distributed in 30 of the 50 states, through 2,300 stations.
– What did Biden announce? †
Joe Biden announced Tuesday from the rural state of Iowa that the Environmental Protection Agency (EPA) would urgently lift a restriction banning the sale of E15 during the summer (between June 1 and September 15). A restriction initially introduced due to concerns about air pollution, which can be especially problematic in summer.
In 2018, former President Donald Trump also wanted to lift this restriction, to appease farmers amid a trade war with China. But a court decision eventually overturned this measure.
According to the current White House, E15 can save an average of 10 cents per gallon of gasoline (4.5 liters) at current prices.
– Consequences linked to cultures –
In order to assess the environmental impact of bioethanol, it is also necessary to take into account the greenhouse gas emissions associated with the crops needed for its production.
And “ethanol’s carbon footprint compared to gasoline is not as good as initially thought,” Tyler Lark, a scientist at the University of Wisconsin-Madison, told AFP.
In 2005, the Renewable Fuel Standard determined that an increasing amount of biofuel for transportation is being sold in the United States. A law further expanded in 2007.
Result: Between 2008 and 2016, 2.8 million hectares of maize were added, according to a study published in February in the journal PNAS.
But according to Mr. Lark, the lead author, the consequences of converting land to maize cultivation were underestimated at the time.
“This plows your land around that could trap carbon dioxide,” he explains.
In addition, some of the fertilizer used to grow corn emits nitrous oxide (N2O), a very potent greenhouse gas.
For example, the emissions of greenhouse gases related to gasoline or ethanol are ultimately comparable, the study concludes.
Other consequences listed by the experts of the development of these cultures: the pollution of water by fertilizers, or the destruction of wild habitats.
– Consequences in the exhaust pipe –
Once in the tank, bioethanol emits less CO2 per liter than traditional fuels, but more is needed.
In addition, “it produces acetaldehyde and formaldehyde, which are carcinogens, and two of the top five producers of ozone during photochemical fog,” which mainly occurs in the city during the summer, explains AFP Mark Jacobson, a professor at Stanford University.
“And ozone poses a significant health hazard and causes problems in the bronchi, respiratory diseases, asthma,” he sums up. According to him, gasoline and bioethanol are both “terrible”.
Ethanol is “bad for the climate and for air pollution, and spending money on it is detracting from real solutions” such as the electric car, concludes Mark Jacobson.
