Nova Scotia's Liberal government is being urged to revisit its ban on hydraulic fracturing following the release of a new Energy Department analysis that found onshore natural gas resources in the province are worth between $20 billion and $60 billion.

Most of it — up to 4.3-trillion cubic feet — is in shale gas, which would require hydraulic fracturing to recover. The Liberals passed legislation in 2014 banning the practice, also known as fracking.

Ray Ritcey, CEO of the Maritimes Energy Association, said he hopes the report will prompt the government to revisit its opposition. "I think that's too large of an opportunity to dismiss outright," he said.

The onshore petroleum atlas has been in the works since 2013. The report was released this week because of a freedom-of-information filing by the business website AllNovaScotia.com.

Energy Minister Geoff MacLellan said the government has no intention of lifting the fracking moratorium. (Robert Doublett/CBC)

Energy Minister Geoff MacLellan called the untapped potential "enormous," but said Tuesday the Liberal government has no intention of lifting the fracking moratorium.

"No change in policy at this point, but looking forward to the discussion," MacLellan told CBC News. "We made this decision clearly a number of years ago based on Nova Scotians' wishes. If they've changed, we'll certainly have that discussion with the people who put us here. But at this point the ban on fracking will remain."

The analysis concludes the Windsor and Cumberland sub-basins hold the most hydrocarbon potential, based on available geological data.

In addition to shale gas, the study estimates there may be be another 1.4-trillion cubic feet of coalbed methane gas.

When conventional natural gas is included, the report says the province is sitting on seven-trillion cubic feet of hydrocarbons — the equivalent of three Sable Offshore Energy Projects.

"That represented 20 years of work for members of my association," said Ritcey.

The Exxon-Mobil project near Sable Island was Canada's first offshore natural gas development. Gas started flowing at the end of 1999 but it is being decommissioned, as is Nova Scotia's other offshore natural gas project, Encana's Deep Panuke.

Environmentalists say keep the ban

Not surprisingly, environmentalists are pushing back against the suggestion that Nova Scotia should revisit its ban on fracking.

Robbin Tress, of the Council of Canadians, said there's been no change since extensive public consultations earlier in the decade that led up to the ban.

"It is still a dangerous industry that threatens our health, our water and our ability to address climate change. None of those things have changed since 2014," said Tress. "I think the province has a responsibility to maintain their ban on fracking."

Environmentalists are taking comfort in the September 2017 mandate letter from Premier Stephen McNeil to his new environment minister, Iain Rankin.

It said Rankin is expected to "continue to enforce the moratorium on fracking for onshore natural gas."

On Tuesday, Stephen Thomas, of the Halifax-based Ecology Action Centre, welcomed the province's commitment to maintain the ban and dismissed the atlas.

"It is a waste of time, money and expertise to create and promote an atlas for something we've decided, as a province, to prohibit," he said.