'Greener' alternatives may be harmful too

Transitioning from fossil fuels to electric-powered technology is widely believed to be the best way to lower carbon emissions.

But is that the real solution? Certainly not, especially in India and China, warns a new study.

"Knowing where the electricity comes from to power those 'eco-alternatives' is critical," said researcher Chris Kennedy of the University of Toronto.

"If that electricity comes from burning oil and coal, it might mean that green alternatives aren't that green after all," he added.

Although regions may welcome 'green' technology like electric vehicles, high-speed rail and geothermal heating, they aren't green if the electricity to power them creates even more carbon emissions than their oil-driven counterparts, the researcher said.

Kennedy's study proposes a new decision-making threshold for when to move from fossil fuel technology to electric power.

It says that a region needs to produce its electricity at a rate below the threshold - approximately 600 tonnes of carbon dioxide equivalent per gigawatt hour (GWh).

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 greenhouse gases (measured as 'CO2 equivalent') 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, the study warned.

"Countries such as these generate much of their electricity using coal, which produces about 1,000 tonnes of CO2 equivalent per GWh - nearly double the suggested threshold," the researcher said.

Natural gas, on the other hand, produces 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. It might even be more carbon friendly to fly," Kennedy said.

The study was published in the journal Nature Climate Change.