THE consultation period for the government's Energy White Paper ends on 14 April. To put the current debate in context, the UK government is committed to the idea put out by the Royal Commission on Environmental Pollution, that the world's governments should take action to limit global average temperature rises to 2C by 2050.

Many environmentalists would argue that in terms of climate impact, while it might not sound like much, even a 2C rise in average global temperatures is likely to have serious effects.

However, the fact is that global temperatures are rising and carbon emissions are playing a significant part in that rise. To slow or halt rising global temperatures, we have to cut carbon emissions and targets have to be set.

As any reading of the government's White Paper shows, it is going to take dramatic action to cut carbon emissions enough to hold the rise to just 2 per cent.

According to the Intergovernmental Panel on Climate Change (IPCC), the world's surface temperature increased by an average of 0.6C in the 20th century. That was enough to cause sea levels to rise by four to eight inches, claims IPCC's website.

In its 2003 Energy White Paper, the government set energy efficiency at the heart of UK energy policy. The White Paper announced the government's long-term goal to reduce the UK's carbon emissions by some 60 per cent by 2050, with significant progress goals set for 2020. The follow-up paper, Energy Efficiency: The Government's Plan for Action, appeared in April 2004 and set out how the energy efficiency strategy in the White Paper would be delivered. The aim was to reduce annual carbon emissions by more than 12 million tonnes by 2010.

British Nuclear Fuel (BNFL) argues that on the basis of the current energy policies in the UK, UK emissions in 2020 will be between 144 and 148 million tonnes of carbon (MtC) - about 30MtC more than where the UK government wanted to be by 2020.

There are various problems with the government's energy policy, BNFL says. These problems make it difficult to imagine how the UK could get private investment to back a resurgence of the UK nuclear power industry if the politicians and the public decide that nuclear power does have, after all, a place in a "balanced UK energy policy".

But first, why should the UK even think about reinvigorating a nuclear industry it has been intent on closing down since the 1960s? The simple answer is that nuclear power is carbon-free. When facing a catastrophic climate event, arguments over the optimal way of disposing of spent fuel rods seem moot. Once people register this fact they tend to stop worrying about nuclear power as a threat and start to see it as part of the solution.

To stay with this point, BNFL points out that there has been a significant change of heart on the part of the general public in the UK. A spokesperson for BNFL says that the Nuclear Industry Association commissioned MORI (Market & Opinion Research International) to research UK attitudes to nuclear power each year for the last five years.

In 2001, asked if they support or oppose the introduction of new nuclear power stations as the old ones close, 60 per cent of respondents said they were opposed to the building of new stations, while just 20 per cent were in favour. Asked the same question in 2006, the opposition to new-builds dropped from 60 per cent to 28 per cent, while the number of those supporting the idea more than doubled, from 20 per cent to 41 per cent.

"This is a huge shift of opinion on a topic that most people would once have thought of as unequivocally settled," the spokesperson said.

Analysing why this shift has come about takes us into more complex reasons for the change in sentiment regarding nuclear. In addition to the fear over global warming, there is public concern over security of supply as far as energy is concerned as the UK moves over to becoming a net importer of gas. There is also mounting concern over the cost of gas and gas-generated electricity, as gas prices spiral upwards.

All of this has created the kind of climate in which the government can start to at least hint that it would like to think of nuclear as an option in the UK's energy mix. However, its current thinking - insofar as it is prepared to admit that it is considering nuclear at all - is that any new stations will have to be built with private investment, not public money. This is where the systemic problems in the UK's current energy scenario come into play.The industry considers the absence of any policy at all on nuclear waste is a total stumbling block to private investment.

The most likely scenario is underground disposal, which what the Finns have done and the route the Swedes and the US say they prefer. But, even here there are arguments about whether the waste should be sealed forever below the surface under concrete, or whether access should be left in case future technologies are developed that render it either useful or less dangerous.

Aside from the waste issue, there is the problem that the EU's carbon emissions trading scheme runs out in 2012 and there is as yet no framework to replace it. Anyone investing in a nuclear power station now will, in all likelihood, not have produced a kilowatt of electricity before this scheme finishes. Clearly, if investment is to happen, then the government is going to have to not just agree to nuclear - which it still seems unsure about - but it will also need to create a stable carbon emissions trading scheme that favours nuclear.

Industry insiders believe that if the government came up with a long-term regime that encourages investment in nuclear power to come forward, it would also benefit other low carbon, high capital projects like the Severn Tidal Barrage.

Of course, the UK's current renewables regime is not the same thing at all. The renewables regime encourages onshore wind power because wind is what works at the moment. The renewables scheme has been designed to be technology-neutral and to leave it to the market. But by definition, a short-term deregulated solution that just leaves everything to the market will just create more of what the market finds most profitable at the moment, which is on-shore wind. The government will need to think this through more carefully.

If the government did decide to give the green light to nuclear, it has several options. It could decide to replace existing stations. That route would do nothing to help the UK cut carbon emissions. Nuclear power already produces 20 per cent of the UK's energy, and replacing old with new leaves the carbon equation unchanged.

For nuclear to really play a role in helping the government to achieve its 2050 targets, it will have to double current capacity. That seems a big step for a country that is still predominately anti- nuclear, but who knows what change of attitude another two years of rocketing gas prices will bring about? We may not yet have an agreed permanent solution to nuclear waste, but the odds against that stopping the nuclear card from being played seem to have fallen markedly over the last 18 months.