Nuclear power isn't the answer to reducing carbon emissions for electricity generation, new research has found.
Researchers from the UK looked at data from 123 countries over 25 years, and found countries with large nuclear energy generation capabilities don't have significantly lower emissions than those without. In poorer countries, having nuclear power was even linked with higher emissions.
Instead, countries looking to lower their emissions should invest in renewables.
"The evidence clearly points to nuclear being the least effective of the two broad carbon emissions abatement strategies," said Benjamin K Sovacool, professor of energy policy at the University of Sussex, who led the research.
Energy production using nuclear power doesn't emit carbon, but mining the necessary resources can be energy intensive - perhaps creating emissions. The World Nuclear Association - which represents most of the world's nuclear energy firms - says with demand for electricity increasing, it will be essential.
"Concerted international efforts over the past 20 years have increased the amount of electricity generated by wind, solar and other renewable sources, but have failed to displace fossil fuels from the mix," its site reads.
"In order to achieve the deep decarbonisation required to keep the average rise in global temperatures to below 1.5C, combating climate change would be much harder, without an increased role for nuclear."
But the study, using data sourced from the World Bank and International Energy Agency, found nuclear programmes don't mix well with renewables.
"Nuclear and renewables tend to exhibit lock-ins and path dependencies that crowd each other out, identifying a number of ways in which a combined nuclear and renewable energy mix is incompatible," the authors said.
"These include the configuration of electricity transmission and distribution systems where a grid structure optimised for larger-scale centralized power production such as conventional nuclear, will make it more challenging, time-consuming and costly to introduce small-scale distributed renewable power.
"Similarly, finance markets, regulatory institutions and employment practices structured around large-scale, base-load, long-lead time construction projects for centralised thermal generating plants are not well designed to also facilitate a multiplicity of much smaller short-term distributed initiatives."
Dr Sovacol's colleague and co-author Andy Stirling, professor of science and technology policy, said nuclear energy doesn't appear to be the saviour its backers say it is.
"Our findings show not only that nuclear investments around the world tend on balance to be less effective than renewable investments at carbon emissions mitigation, but that tensions between these two strategies can further erode the effectiveness of averting climate disruption."
New Zealand investigated the possibility of nuclear energy in the 1960s and 1970s. At one stage a nuclear reactor was mooted for Northland's Kaipara Harbour, but the discovery of the Maui gas fields put it on ice. A royal commission in the late 1970s suggested we'd need nuclear power by 2005, but New Zealand turned against all things nuclear in the 1980s.
The share of electricity produced by renewables in New Zealand has increased in recent years, from 64 percent in 2008 to 82 percent now. The Government has a goal of 100 percent by 2035.
The total energy burden however still falls largely on fossil fuels - only 40 percent of our total energy production is renewable, mostly thanks to transport.
None of New Zealand's mainstream political parties are proposing New Zealand build nuclear power plants, even though the New Zealand Nuclear Free Zone, Disarmament, and Arms Control Act doesn't actually ban it.
The University of Sussex research was published in journal Nature Energy.
