Ecological and political fears cloud Poland's shale gas hopes

Over the past ten years, the US success in extracting gas from shale rock deep underground has transformed its energy landscape. Several countries in Europe, including France and Poland, are believed to have huge reserves too. American geologists initially said Poland could be sitting on enough gas to supply domestic need for 300 years, sparking a "gas rush". But only six wells have been hydraulically fractured so far and geologists fear their initial calculations may have been too optimistic.