[Faced with the task of decarbonizing our electricity supply, it would be foolish to rule nuclear power out of the mix, writes Baroness Worthington, a British environmental campaigner and Labour life peer in the House of Lords, in her reply to Dr. Becky Martin, whose open letter was published in The Ecologist.]

Dear Dr. Martin,

Thanks for your letter. The debate in the Moses Room to which you refer was not about the nature, design or location of a nuclear waste storage facility but about whether or not such a facility constitutes an infrastructure project of national significance. Which clearly it does.

As for the decision making process for nationally significant infrastructure clearly a balance needs to be struck, however, our elected national Government and its Secretaries of State are entrusted with decision making powers on many issues in order to ensure national priorities can be advanced, informed by local considerations.

Climate Change Is My Top Priority

Far from being a superficial concern, as you seem to imply, climate change is for me the pre-eminent threat facing our society and I have dedicated most of my career to seeking to address it. I have changed my position on nuclear power because I have studied it in depth and concluded that much of the opposition to it is not based on science and the economics can and will be improved over time.

It is clear that as is the case with every technology, there are more appropriate and less appropriate ways of using it and I am no apologist for the mistakes that have been made in the nuclear industry. As a proven source of reliable low carbon energy it would, however, be reckless to rule it out in the fight against climate change just as it would be reckless to rule out large scale hydro, solar, biomass, wind and carbon capture and storage.

I'm afraid the evidence you cite in support of the idea that nuclear is not a low carbon energy source is not very persuasive. Firstly, the article to which you refer in The Ecologist misunderstands the nature of the 50g/kwh CCC's proposed target for the carbon intensity of electricity in 2030.

This is proposed as a yearly average for emissions arising from all electricity generation in that year. The carbon budgets from which this figure is derived cover the emissions arising upstream of generation and therefore the LCA of technologies is not relevant and as you yourself point out highly uncertain. To use it in this context is inappropriate and involves double counting.

When considering direct emissions from electricity generation please bear in mind that unabated coal emissions are in the range 850-1200g/kwh not including up-steam emissions from the extraction and transportation process.

Turning to your fears about the potential future cost of uranium it is true that the natural radioactive elements, which sustain life on this planet, will one day cease to produce radiation. But that day is an incredibly long time away.

The process of splitting an atom generates new radioactive elements that can be recycled for use as fuel. This need not be limited to Uranium as the much more abundant element Thorium can also be kick-started in this way to provide a virtually limitless source of energy.

The lack of progress in advanced forms of nuclear is lamentable but it is because of politics and the structure of the existing industry not physics and engineering. You appear confident that no new nuclear technology will emerge any time soon, however, having spoken to many of the people working on new reactor designs around the world I'm afraid I do not agree.

Time will tell which of us is right but in any case this question has little if any bearing on the question of how Government deals with current nuclear waste.

I find it curious that you fear support is currently being diverted away from renewables, when the only projects currently receiving direct support are renewables. I believe the best way to achieve secure, affordable, low-carbon energy supplies is by encouraging a diversified mix of generating technologies, especially as many renewable and energy storage technologies are still developing.

Nuclear Power Has an Important Role in Our Energy Mix

Nuclear projects may also be granted the same support in the form of contracts for difference but that will not be to the exclusion of renewables. The task of decarbonising our energy system, still dominated by unabated fossil fuels, is large enough to accommodate all forms of low carbon technology. And I disagree that these long-term contracts will "guarantee fuel poverty" since they will insulate against higher future carbon prices.

When it comes to our use of energy there is very little beyond photosynthesis for growing for food that is truly 'natural.' I believe we need an informed debate about the different risks associated with our energy use now and in the future.

It is clear that to sustain the world's population and lift millions from poverty we now need to harness a huge amount of resources to generate clean power. All technologies involve the conversion of ores, manufacturing and distribution processes, all have a foot print on land or sea and all compete with the preservation of natural landscapes and biodiversity.

Nuclear power is the most concentrated source of power available today with the smallest footprint. It is not without its challenges but these are not insurmountable. I urge you on moral, ethical, scientific and environmental grounds to rethink your opposition to it.

Yours sincerely, Bryony.