The inquiry into fracking being undertaken by the Parliamentary Commissioner for the Environment is extremely welcome. The technique, under which high-pressure blasts of water, sand and chemicals are used to fracture rock to release gas and oil, has generated a lot of emotion but far too little light. On one side, the Greens have called for a moratorium on fracking despite the lack of conclusive evidence about its ill-effects. On the other, there has been the usual accusation that those opposed to such new practices are Luddites, and the Energy and Resources Minister's unhelpful statement that "the Greens want a moratorium on everything". Both sides of the argument stand to gain much from a science-based investigation.

Opponents of fracking claim it can contaminate groundwater, release harmful gases into the atmosphere, and trigger earthquakes. Yet the technique has been used in Taranaki for the past 20 years, with 41 exploration wells employing it over the past decade. A report last year by the Taranaki District Council concluded it was unlikely that contaminants from the practice would reach overlying freshwater aquifers in the region, but that this was "not impossible".

Such inconclusive findings increase the significance of the inquiry by the parliamentary commissioner, Jan Wright. It is important that she has seized the initiative because the prospect that exploration companies will also use fracking on the East Coast and in Canterbury has heightened community concerns. Marise Lant, a spokeswoman for East Coast iwi Ngariki Kaiputahi, summed up the predicament when she noted that "at this point there's a lot of information we could be getting".

Dr Wright's inquiry will canvas only the environmental risks, but the iwi should also be looking at how the employment of fracking could boost regional prosperity and the national economy. Overseas, it has transformed the natural gas industry. Ten years ago, almost all of the United States' production came from traditional wells reached by vertical drills. But in a remarkably short period, the use of fracking to break up shale formations and release gas has become both cost-effective and widely practised. In 2009, about 14 per cent of America's natural gas came from shale. By 2035, that is projected to rise to 46 per cent.

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In an energy-hungry world, there is a clear case for the practice if it embodies no environmental threat, or risks that can be comfortably contained. Much of the evidence overseas points to this not having been the case when regulation of the exploration industry was weak and fracking was done incorrectly. This is the area where Dr Wright's investigation should shed most light.

According to former Environment Minister Nick Smith, issues have arisen when fracking has been used in quite shallow shales. This may considerably increase the risk of groundwater contamination and the release of dangerous gases. Dr Wright will also examine reports of swarms of earth tremors after fracking. In Oklahoma, a 20-fold jump in the number of earthquakes in the past two years has been linked to a surge in use of the technique. A similar, if less serious, phenomenon has been recorded in Blackpool, England, where the many tremors were of a non-destructive magnitude.

Such alarms have caused some countries to place a moratorium on fracking. They remain to be convinced that the rewards from the practice are sufficient to outweigh the risks. Their response enhances the importance of Dr Wright's findings, which are due by the end of the year. They should provide a science-based foundation for the future conduct of oil and gas exploration in this country.