Concern about global warming and increased prices for fossil fuels and a potential energy gap have combined to change the political climate on nuclear energy at Westminster, but brought a new stand-off with Holyrood. The Labour government's green light for a third generation of nuclear power stations nevertheless leaves some serious long-term issues unresolved. In Scotland, the SNP government's refusal to allow any new nuclear power stations, although previously welcoming a five-year extension of Hunterston B to 2016, leaves a potential gap when Torness reaches the end of its lifespsan in 2023.

The boldest part of the government announcement is the requirement for the energy companies to meet the entire cost of the new stations from developing and building to eventual decommissioning and waste management. According to John Hutton, the Business Secretary, that means the taxpayer will not be liable for any costs except in the unlikely event of a nuclear emergency; since no nuclear power stations have been built in recent times without government subsidy, that will be met by scepticism by a wider group than environmental campaigners. As far as the taxpayer is concerned, however, the cost of decommissioning the current reactors must be factored into the cost of electricity bills, even in Scotland, as John Swinney pointed out. The stand of the SNP-Green alliance against new nuclear power stations will be welcomed as a victory by anti-nuclear environmentalists, but risks rejection by expert opinion which now sees new-generation nuclear as providing an acceptable low-carbon solution to provide a constant base load that cannot be supplied by the fluctuating nature of generation from renewables.

The disposal of waste remains the outstanding problem associated with nuclear power generation. One argument in favour of building the new generation of nuclear reactors is that they produce far less radioactive waste than those currently nearing the end of their lives, but it is a flaw in the government's proposals that the problem of the waste we already have, even before we generate any more, must await a white paper later this year. The simultaneous publication of an Energy Bill providing for increased generation from renewable sources, investment in offshore gas storage and carbon capture and storage is an important and welcome indication of a step towards a low-carbon, mixed-fuel economy. It is also good news for Scotland, whether or not the stance against building new nuclear power stations is continued, because clean coal technology and carbon capture and storage command support. We must also support wave and tide technology: an island nation that does not include incentives for developing these natural resources in the 21st century has a hole at the heart of its energy policy.

The key to success for the nuclear option will be a strengthening of the EU's carbon emissions trading scheme, which has the potential to make nuclear generation commercially viable. Whether the first new nuclear station is built, as the government hopes, before 2020, will depend on it being a reasonable business proposition. Whether by that time they remain "unwanted and unnecessary" in Scotland also remains to be seen.