The Netherlands has banned fracking until 2020. Over the past several years, a number of other European countries declared a ban on exploiting new natural gas deposits. So, is the apparent European shale gas boom over?
One more country has decided to put a halt on exploiting shale gas reservoirs.
The Dutch government last week placed a five-year ban on commercial fracking. A final decision on the future of fracking in Holland is expected at the end of this year.
Hydraulic fracturing - commonly known as "fracking" - is used to get natural gas out of mineral deposits like coal beds or shale.
Fracking uses water pressure to crack underground rocks. The technology of fracking isn't new - it's been around for decades. New are the sources that companies want to exploit.
Fracking is going through a boom in the United States, where mining companies say high energy prices are forcing them to look for more unconventional deposits of gas.
About five years ago, a shale gas boom started in Europe, with countries looking into the potential of this new fossil fuel source. Natural gas from fracking was initially advertised as "green" and "environmentally-friendly" energy.
Many countries, particularly in Eastern Europe, hoped that shale gas would make them energy-independent from Russia.
Nowadays, these high expectations have more or less faded in most parts of Europe.
When shale gas is being "fracked," high-pressure water is injected into the rock at depths of 1,000 to 5,000 meters below the earth's surface. Sand is then sent down to fill up the cracks and make sure they stay open. Later, natural gas passes through the sand to reach the surface.
Because sand and water do not mix well, drilling companies have to add chemicals to turn this into a homogenous, viscous fluid.
Other chemicals are to break up the water-sand mixture again, stop rocks from clogging things up, and to stop bacteria and yeast from contaminating the fluid.
Activists fear that this "chemical cocktail" could contaminate the groundwater. And if not the chemicals, then the natural gas itself could cause pollution: In 2010, a documentary about fracking in the US claimed that methane water had polluted waterso heavily through the process that it was possible to set fire to the water.
Another fear is that fracking may cause earthquakes. In the US and northern Germany, some earthquakes over past years are suspected to be linked with natural gas drilling. Activists fear that fracking for shale gas might cause even more tremors.
Environmentalists and concerned citizens in many European countries went on the defensive when it became known that companies were eyeing potential new shale gas deposits.
France is apparently one of the countries with the highest potential for developing such unconventional hydrocarbons. However, a fracking moratorium has been in place since 2011.
Bulgaria, the Czech Republic and others followed France's example when environmental concerns became overwhelming.
Even in those nations where the technique isn't banned, such as the United Kingdom and Spain, regions of these countries - like Scotland and Wales in the UK, or Catalonia in Spain - still decided to ban fracking regionally.
Germany continues its moratorium on exploiting shale gas deposits. A new law in Germany - which will probably be decided on after the summer - is not likely to impose an outright ban on fracking, but will restrict it heavily. It will only allow scientific test-drilling under strict conditions while assessing the risks and environmental impact.
Not worth the effort
In Eastern European countries, many boreholes have been drilled.
Particularly Poland looked to be the frontrunner of the European shale gas boom. But things have turned out differently.
Test wells have not performed as expected, foreign investors have pulled out and sustained environmental protests have hampered drilling plans.
The same thing happened in Romania: Poor exploration results and prolonged protests by environmentalists caused US energy giant Chevron to pull out of Romania.
Other countries have decided that fracking wasn't worth the effort from the beginning. Norway and Sweden found that exploiting their shale gas resources wasn't economically viable.
A fracking-free Europe might in the end become a reality - due to a simple cost-benefit calculation.