A recently published study proposes a new decision-making threshold that could indicate when switching to green alternatives like electric vehicles may actually increase overall carbon emissions. This is because electric alternatives aren’t actually green if the electricity to power comes from burning coal and oil.
For electrification (the move from fossil fuel technology to electric power) to actually lower emissions, a region needs to produce its electricity at a rate below approximately 600 tonnes of carbon dioxide equivalent per gigawatt hour (GWh), says Kennedy. This means that for every gigawatt hour of electricity generated (the power needed to run about 100 homes for a year), less than 600 tonnes of greenhouses gases can be emitted.
If a region’s electricity production exceeds this 600-tonne threshold, such as in countries like India, Australia and China, electrification could actually increase carbon emissions and accelerate climate change. According to the study, coal generates around 1,000 tonnes of CO2 equivalent per GWh, natural gas around 600 tonnes, and hydropower and nuclear energy produce nearly zero.
“You could speculate that incorporating electrified technologies such as high speed rail in China may not lower overall emissions,” says Kennedy. “It might even be more carbon friendly to fly.”
Kennedy found that it also matters where you live in a country, citing a study that found using plug-in electric vehicles emitted less carbon when used along the west coast of the United States, but produced the same, if not more, carbon when used in the Midwestern U.S.
According to Kennedy, his new threshold reframes the climate change debate “by encouraging individuals around the world to better understand where their electricity is coming from before they adopt supposedly eco-friendly technologies.” It will also help politicians make smarter energy decisions when developing national and international environmental policies and incentives.