The environmental campaign group’s analysis, based on figures by the US Energy Information Administration (EIA), found that of the 16 per cent fall in carbon emissions, 40 per cent came from the switch to renewables.
Wind power accounted for 32 per cent of the fall, while only 30 per cent came from the switch to gas, the same as improved energy efficiency.
Greenpeace said this contradicts the long held belief that the shale gas boom has been largely responsible for the fall.
Greenpeace energy analyst Lauri Myllyvirta said: “Our analysis shows that it was the clean tech boom, not the fracking rush, that slashed the bulk of carbon emissions from the US power sector.”
The analysis showed that most of the power vacuum left by coal (56 per cent) was filled by renewables and energy efficiency, with the rest being covered by gas-fired generation.
This comes just a week after a major international study was released showing that rather than a reduction in emissions, the shale boom may actually lead to an increase in emissions of up to 11 per cent by 2050.
Myllyvita added: “The supposed climate benefits of fracking have been a big selling point for the shale lobby, but this myth has now been cut down to size by compelling new evidence.”