European Commissioner for Environment Janez Potocnik said domestic natural gas production among member states is in decline.
"We need to dig more or deeper to get the same amount of energy," he said.
New sources of natural gas from shale reserves seem to provide an attractive substitute for carbon-intensive fuels like coal, he said. Prices have come down for natural gas, however, and markets could see that trend continue if the United States starts to export natural gas from shale by the end of the decade.
Potocnik said, however, that it's more expensive to extract shale in Europe and the environmental laws are different than in the United States.
"The jury is still out as there are large uncertainties about recoverable volumes in the EU," he said. "But most analysts recognize that, even in the most optimistic case, European shale gas development can only compensate for the decline in conventional gas production."
Poland, Ukraine and Lithuania are among the Eastern European countries considering shale exploration. Potocnik said production from some members is expected by 2014. Shale, however, is only part of a longer package of options meant to ensure EU energy security.
"To secure the longer term climate integrity, efforts to explore and exploit shale gas also need to be matched by efforts to promote energy savings, reduce coal and accelerate the uptake of renewables," he said.