Trying to tackle climate change by importing more nuclear power from the mainland is the wrong approach, green groups say. The carbon emissions reduction target the government proposed for the city yesterday is also too lax compared to standards set by the United Nations for developed countries. 'The ... defective fuel rod at the Daya Bay nuclear plant earlier this year has highlighted that there is little transparency in contingency plans of the plant if there is any possible case of radioactive leakage,' William Yu Yuen-ping, head of WWF Hong Kong's climate programme, said. Nuclear power was hardly a green energy source, he said, given that the processing of raw materials and building power stations consumed a vast amount of fossil fuels. Dealing with radioactive waste has also been a big problem worldwide. Officials proposed in the consultation document to raise the share of imported nuclear power in the city's fuel mix from the current 23 per cent to 50 per cent by 2020. Assuming the cost of nuclear per unit is HK$6, and with a 2 per cent annual consumption increase in Hong Kong, the cost of achieving the target by 2020 would be HK$16.8 billion per year, he said. An earlier study by WWF and engineering firm Ove Arup showed the city could meet the government's reduction target by raising the share of natural gas from 23 to 75 per cent by 2020 - rather than 40 per cent as officials now suggest - and through means such as tightening building energy efficiency standards and offering incentives to save energy. Even with such a drastic change in the fuel mix, officials have set a loose target for the city, Hahn Chu Hon-keung, environmental affairs manager of Friends of the Earth (HK), said. The UN Intergovernmental Panel on Climate Change proposed developed nations cut carbon emissions by at least a quarter from the 1990 level by 2020 - which means Hong Kong should lower its total emissions to 26.5 million tonnes by that year. But officials now expect that, with all the measures in place, Hong Kong will still be emitting not less than 28 million tonnes that year - 1.5 million tonnes short of the UN target. 'Hong Kong, as an international city with a very mature economy, is able to fulfill the duty to meet the UN target,' Chu said. 'The government has failed to say whether it is willing to shoulder some of the financial costs borne by the measures to cut emissions. I'm worried the costs will end up coming out of citizens' pockets.' Dr Man Chi-sum, of Green Power and a member of the energy advisory committee, said: 'The government's mentality is to just pay for nuclear imports and that's it. The document doesn't tell people the disadvantages of nuclear ... It doesn't either bother to throw out suggestions such as giving citizens incentives to cut energy consumption. Nor does it assess whether - with all the energy-saving measures in buildings and district cooling - we will still be needing so much more nuclear.' Man said the government was likely to source nuclear power from an upcoming plant near Daya. Alexis Lau Kai-hon, of the University of Science and Technology, said nuclear energy is an option for the city as it has less room for renewable energy development. 'But by investing in a mainland power plant, Hong Kong should take the opportunity to raise transparency in plant management and monitoring.' Greenpeace called the strategy 'the most irresponsible and dangerous path' to tackle climate change, urging officials to look into research on renewable energy in the region.