European shale gas experts say more environmental studies are needed to address public concern about the security of extraction of the fossil fuel.

Rene Peters, chairman of the EU Shale Gas Expert Group, told a conference in Warsaw on Tuesday that data gathered from extensive exploration in the United States does not apply to Europe, where geological and environmental conditions are different. The conference, on the sidelines of U.N. climate talks, concerned shale gas's potential as a bridge between coal and renewable energy.

Concerns about the environment are among the key reasons holding back the development of the shale gas industry in Europe, where some countries have moratoriums on drilling. Only Britain and Poland are exploring their deposits, though a local protest halted exploration in southern Britain in August.