Sustainability is the current term favoured by politicians to signal their credibility. In an age facing the challenge of climate change, the environmental sense of the word has become dominant. It should not be forgotten, however, that it can equally be applied to argument, and proposals that are not sustainable turn to political posturing. Scotland's new waste policy, outlined by Environment Secretary Richard Lochhead, makes much of sustainability as the concept underpinning the strategy to increase recycling and reduce landfill. This means that by 2020 we should be recycling or composting 60% of waste, rising to 70% by 2025 and, by then, only 5% should going to landfill.

This is moving in the right direction, but targets are meaningful only when there is a prospect of achieving them, and the reality behind these figures is that Scotland dumps 70% of waste in landfill. To change that to 70% recycling will require a U-turn in mindset.

The evidence from other countries is that nearly all household waste can be recycled. The Dutch, for example, send only 2% of waste to landfill, but the rubbish accumulating in our own backyard is a warning of the gap between aspiration and reality. The latest figures show waste from the average household in Scotland increased by 2% between 2004 and 2006, despite improved recycling rates at some councils. This illustrates the essential problem: we are failing to reduce the amount of overall waste produced, mainly in packaging.

It is that stumbling block, combined with the prospect of fines for failure to meet European regulations on dumping of waste in landfill by 2013, which has prompted several local authorities to consider building incinerators. The pros (a reduction in landfill) and cons (pollution and less emphasis on reduction) of incineration are the new environmental battleground in Scotland. The trade-off for those who accept both points of view is that incinerators can generate energy as a by-product. The most efficient tend to be those used for local combined heat and power schemes. The strategy announced by Mr Lochhead is an attempt at consensus: inefficient incinerators will not be allowed and no more than 25% of municipal waste can be used to generate energy by 2025. The clampdown will cause problems for councils, such as those in the Lothians and Lanarkshire, which were planning to incinerate up to 40% of waste, and they will have to produce practical alternatives quickly.

The compromise has failed to satisfy the Greens, whose two MSPs are keen to exert influence on the environmental policies of the SNP minority government. Mr Lochhead now speaks of a zero waste society, but to achieve that the new Cosla working group and zero waste think tank must achieve zero waste on its time and £150m budget.