The government is entitled to be heartened by the results of a Herald-DigiPoll survey this week showing that a majority of New Zealanders back its plan to increase exploration for oil, gas and minerals. But it should not get carried away. The public approval it is entitled to infer is heavily circumscribed.

The poll, conducted late last month, showed that 27 per cent supported the idea and 40 per cent cautiously supported it. So a significant portion of the support is qualified, and it is not hard to imagine that those who offered "cautious support" were giving voice to at least mild misgiving.

When the qualified support is combined with the implacable opposition, seven of 10 of us are not enthusiastic. And the question was about finding out what mineral wealth might be available to us; it is a long way from saying we should dig it up.

The significant difference from the proposal floated in September 2009 - and scuttled nine months later - by Energy and Resources Minister Gerry Brownlee is that mining areas of the conservation estate is now off the political agenda. After unsuccessfully fudging the matter in Parliament, Brownlee himself finally conceded that there was "a huge public outcry".


But at the same time, he referred to the danger that controversy over allowing mining on a small area of the conservation estate would undermine an industry with "enormous potential". The key here is the word "potential". There is ample dispute as to what the value might be to the economy of large-scale mining. Critics argue that few jobs are created for people other than specialist technical staff, many of whom have to be imported, and that the mining industry overstates the positive impact it might have on the many small communities ravaged by unemployment. The experience in Western Australia, where plenty of low-skilled New Zealanders are finding work, would appear to argue against that, but the mineral reserves there occur in quantities beyond even Brownlee's most fevered imaginings.

Likewise, there is some hard calculation to be done about what we might lose - by way of species habitat, recreational utility value and international image - if we move into large-scale mining.

But those are arguments for another day. Conservationist groups who argue against prospecting do their cause no good.

Even they should accept we need to find out what's there first.

Then we can do the maths and have the discussion.

Our economy is in no shape to allow us the luxury of ignoring the potential riches beneath our feet.

It might not be possible, or desirable, to get them all out, but surely we can benefit from some of the bounty bestowed on us.