Image caption Fracking has been blamed for minor earthquakes

UK shale gas exploration would have a "similar" carbon footprint to other fossil fuels, according to a new study.

A report for the Department of Environment and Climate Change (Decc) estimates that greenhouse gas emissions would be similar to home-grown gas but lower than imported gas or coal.

Shale gas could benefit the UK, through energy security and jobs, Secretary of State Ed Davey told the Royal Society.

Greenpeace said low carbon renewables were a better way to meet energy needs.

The new report, by Decc chief scientific advisor Prof David MacKay and Dr Timothy Stone, senior advisor to the Secretary of State, looked at the potential greenhouse gas emissions from the production of shale gas in the UK.

It concluded that the net effect would be "relatively small".

Carbon footprints Carbon footprint for UK shale gas extraction is in the range of 200-253 g CO2e per kWh of chemical energy

This compares with 199-207g for gas extracted from conventional sources (home-grown gas) and 233-270g for gas imported from outside the EU

When shale gas is used for electricity generation, its carbon footprint is in the range 423-535g

The carbon footprint for coal is 837-1130g

Prof MacKay told BBC News: "The emissions from shale gas in the UK will be similar to those of liquefied natural gas.

"And secondly, as with any fossil fuel reserve if you put extra fossil fuel into play, if you don't also have global climate policies then we think it's credible that global cumulative emissions could increase.

"So we think it's essential that shale gas use should be accompanied by continued global climate policy action."

In a speech to the Royal Society, Ed Davey responded to the findings.

The solution to our energy problems is still a roll-out of high-tech low carbon renewables which would be incentivised by supporting the clean energy target in the Energy Bill, but Davey is currently blocking it Leila Deen, Greenpeace

He said: "Gas, as the cleanest fossil fuel, is part of the answer to climate change, as a bridge in our transition to a green future, especially in our move away from coal.

"We have to face it: North Sea gas production is falling and we are become increasingly reliant on gas imports. So UK shale gas could increase our energy security by cutting those imports.

"Home-grown gas, just like home-grown renewables and new nuclear, also provides jobs for our people and tax revenues for our society."

He added that regulation to protect the local environment must be followed "to the letter".

However, Leila Deen, energy campaigner at Greenpeace, said Mr Davey was "endorsing the use of a fuel that remains highly polluting, damages our countryside and scientists say must be largely left underground".

"The solution to our energy problems is still a roll-out of high-tech low carbon renewables which would be incentivised by supporting the clean energy target in the Energy Bill, but Davey is currently blocking it."

Concerns over extraction of natural gas from shale have centred on the risk of small earthquakes and the potential impact on water supplies.

There has also been debate about the impact of the technology on meeting greenhouse gas targets.