Algeria, the world's fourth-largest gas exporter, has decided to develop its shale gas potential as well, but experts fear this could cause severe environmental problems.

Officials say the country's shale gas reserves are 600 trillion cubic feet (17 trillion cubic metres), or around four times greater than its current known gas reserves.

Algeria may be the world's eighth-largest natural gas producer in 2011, according to the BP Statistical Review of Energy, but domestic consumption is surging. Official forecasts say that, from 2019, local demand will eat up all the country's production.

At present, 50 years after it gained independence, the country remains almost totally dependant on hydrocarbons, which account for 90 percent of its exports.

So as long as it fails to diversify its export base, it has no alternative than to develop shale gas, an unconventional fossil fuel, to secure its energy future, experts say.

A new hydrocarbons bill, to be introduced in parliament in the coming weeks, encourages the exploration of unconventional gas and oil resources.

However, the effect on the environment of the production of shale gas is of great concern to ecologists.

Chems Eddine Chitour, director of fossil energy development at Algiers' Ecole Polytechnique, is concerned that the method used for obtaining the fuel trapped in formations of shale rock could be geologically dangerous and also put a strain on the largely desert country's water supplies.

Induced hydraulic "fracturing weakens the ground and the subsoil, making earthquakes more likely," he said.

"It mobilizes vast quantities of water and will permanently destroy the ecosystem of the Sahara. Injecting 15,000 cubic metres (530,000 cubic fee) per well, with a well every 100 metres (yards), is catastrophic for a country with such water scarcity."

Chitour, like many ecologists, also said the chemicals used in the injection risked polluting the water table.

But former Sonatrach CEO Abdelmadjid Attar countered that "conventional hydrocarbon exploitation carries the same environmental risks."

Algiers says safeguards will ensure environmental protection, but Chitour is not convinced.

"The absence of debate on the energy future of the country is a mistake," he said, adding that this would have adverse effects for generations.

There must be a "comprehensive strategy (to ensure) that shale gas will comprise only a very small amount of the energy supply."

The costs of shale gas exploitation are also high, Energy and Mines Minister Youcef Yousfi said, and "exporters and importers will have to share the risk".

And Yousfi's predecessor, Nordine Ait Laoussine, said "there is still much left to do on the conventional side, not only in unexplored areas but also in those already in production."

To develop its shale gas potential, Algeria's hydrocarbons company Sonatrach has signed agreements with the Anglo-Dutch oil group Shell, Italian Eni and Canadian Talisman.

In 2011, Sonatrach drilled its first shale gas wells in the Ahnet basin near Tamanrasset, about 2,000 kilometres (1,250 miles) south of Algiers.

On Thursday, Sonatrach announced a new gas discovery in the southeast, near Illizi, and will also begin offshore exploration in 2014.