Yesterday it was revealed that Gordon Brown and Nicolas Sarkozy will sign an agreement this week to export nuclear technology around the world. Brown hopes Britain can create a skilled labour force working in partnership with France to sell reactors around the globe, supposedly to help combat climate change. But the two leaders will be opening a Pandora's box, which is more likely to damage the solutions to global warming.

Only last Wednesday, the prime minister warned us about rogue states obtaining nuclear weapons and terrorist groups unleashing "dirty bombs". Promoting nuclear power as a global solution to climate change is rather a schizophrenic thing to be doing days later.

Nuclear power and weapons are like Siamese twins. The Nuclear Nonproliferation Treaty (NPT) already embodies an inherent contradiction - seeking to promote "peaceful" nuclear power while trying to restrict the spread of nuclear weapons. Yet, since the treaty was signed, Israel, India, Pakistan and North Korea have all obtained nuclear weapons.

Spreading reactors around the globe will create new terror targets. Most reactors use uranium as a fuel and produce plutonium. A small-scale plutonium separation plant can be built in four to six months, so any country with an ordinary reactor can produce nuclear weapons.

Brown and Sarkozy are promoting this Faustian technology as a solution to climate change. Yet nuclear's contribution can only ever be really small. The danger is that by trying to revive this moribund industry we may in fact kill off the real solutions. A replacement UK programme will only reduce carbon emissions by 4% by around 2024 - too little, too late. Globally, for nuclear power to play a role, by 2050, comparable to coal today about 2500 reactors would have to be built - that is one new reactor every six days. Such a massive programme would require a new nuclear waste dump every few years and two or three uranium enrichment plants every year.

Ministers are putting more effort into encouraging nuclear power than they have devoted to the entire field of renewables over the last 10 years. The worry is that finances and resources will get diverted from the real solutions to climate change.

The question is, not whether there will be a global renewable energy boom, but whether Scotland and the UK will be part of it. While Westminster has conceded no new nuclear power stations will be built in Scotland in the near future, if a substantial expansion of nuclear power takes place in England, it is likely to limit the Scottish government's plans to build a renewable energy manufacturing base. And to reduce carbon emissions by 80% by 2050 Scotland needs to be bringing around 60,000 houses up to a decent standard of insulation every year and installing Low Carbon Technologies, such as solar panels. But we will need Westminster's support to pull it off.

With eight old people dying every hour in the UK from cold-related illnesses in winter, such a massive energy efficiency programme would help Gordon Brown meet his commitment to eliminate fuel poverty, too.

We can't afford to wait until 2025 to see if a new reactor programme is successful, or whether it turns out to be, to paraphrase what the old Scottish Office said about Torness, a £30 billion mistake.

Peter Roche is an Edinburgh-based energy and environment consultant and editor of the website: www.no2nuclearpower.org.uk