KEY POINTS:
On the climate change issue the business community divides into three groups: the deniers, the resigned adapters and the opportunists.
The first group, exemplified by the Business Roundtable and Federated Farmers, think it is all nonsense and will be the ruin of us.
They wonder why something that has always been free, like the gaseous emissions from burning fuels or belching cattle, should now incur a cost.
There's still a lot of uncertainty about the science, they say. Shouldn't we take our lead from the Americans and the Australians? They haven't signed up to Kyoto, have they?
But that point of view is less and less tenable.
The scientists' warnings, as reflected in the periodic reports of the Intergovernmental Panel on Climate Change, are increasingly emphatic.
The best way we know of avoiding a tragedy of the commons is to establish limits, create property rights and set up markets, which is what Kyoto is about.
The eight most powerful industrialised countries have just committed to taking "strong and early"action to tackle climate change.
The European Union, Japan and Canada have adopted the goal of at least halving their emissions by 2050.
Even the two recalcitrants among developed country leaders, George W. Bush and John Howard, have recently been driven to positions which, if viewed from a distance and with a generous spirit, might even be called progressive.
So the skirts of "our trading partners" no longer provide much of a hiding place.
There is a commercial danger in doing little or nothing. It lies in the tension between having a national brand of being clean and green on the one hand, but per capita emissions that are not much below US levels on the other.
The concept of food miles is dodgy - why pick on food, of all the goods transported, and what about the emissions-intensity of producing it in the first place?
But the customer is never wrong and you can't take a supermarket chain to a World Trade Organisation disputes panel.
The second group recognises all this.
They may not like it but they can see the way the world is going: one way or another there will be a price on carbon emissions.
So they need to think about, and if possible quantify, the emissions involved in their own operations and their supply chain, and start factoring some range of carbon prices into their decisions.
Large energy- and emissions-intensive firms already have a sophisticated understanding of their exposure and how they might manage it.
Peter Neilson of the Business Council for Sustainable Development is confident most smaller and less carbon-intensive firms will find that the kinds of emissions reductions and carbon prices (in the US$20 to US$50 per tonne range) are "doable", provided they do not have to replace their capital stock prematurely and most of their competitors are in the same boat.
Most is not all, of course, and the provisos are important.
But the international evidence, he says, is that most producers could achieve a 40 to 60 per cent reduction in their emissions intensity (emissions per unit of output).
That leaves much the smallest group, firms that can see a business opportunity in the response to climate change - or are willing to look for one.
To a large extent the response to climate change is about replacing the technologies, for the most part inherited from the century before last, which we use to generate electricity, propel vehicles and deliver comfortable temperatures to live and work in. These are not little niche markets.
The replacements will need to be designed, manufactured, bought and sold, installed, maintained, financed, insured and so on.
Up to a point one man's cost is another man's livelihood. The trick is to be the other man.
That is not to say the transition will be without cost. The resources devoted to this will not be available for other things.
And beyond that opportunity cost is the deadweight cost that always arises when public policy interferes in the choices people make.
But we don't need Sir Nicholas Stern to explain that the costs of doing nothing to mitigate global warming will be higher, even in the narrow terms of gross domestic product.
Treasury research on what factors throw the New Zealand business cycle around most found that climate has been second only to world commodity prices in influencing how the economy fares, and a much bigger factor than tax rates or monetary policy, for example.
There are farmers in Hawke's Bay right now grappling with the kind of drought that the climate models predict will become more common in a warming world.
And there are lot more of them across the Tasman.