A prototype carbon capture and storage facility by Shell, which was designed to eliminate emissions from hydrogen production, actually has the same yearly carbon footprint as 1.2 million cars, according to a report by Global Witness.
Shell says its Quest plant captured close to five million tonnes of CO2 over the course of five years after it was installed at the oil giant's Scotford refinery in Canada in 2015.
But the report by human rights organisation Global Witness found that over the same half-decade, it emitted just over 7.5 million tonnes of greenhouse gases that weren't captured ? the equivalent to emissions from 1.2 million cars every year.
The greenhouse gases emitted include highly potent methane, which in the short term has a more than 80-times higher global warming potential than carbon dioxide.
Above: the plant failed to capture 7.7 million tonnes of greenhouse gases. Top image: a Shell hydrogen fuelling station 
Global Witness argues that this casts doubts on the messaging pushed by the oil and gas industry that, with the help of carbon capture and storage (CCS) technology, hydrogen derived from natural gas can be used as a "low emissions" fuel to help the world reach its net-zero goals.
"Fossil fuel companies see fossil hydrogen as a way of continuing to make profits from extracting and burning fossil gas, whilst greenwashing it at the same time," the report reads.
Making hydrogen from fossil fuels emits 830 million tonnes of CO2 a yea...