By Gerard Wynn
LONDON, Sept 19 (Reuters) - Developed countries are increasingly bold in planning to reduce nuclear power but hesitant in announcing clear plans to cut greenhouse gas emissions, leaving themselves wriggle room to replace low carbon nuclear generation with fossil fuel gas.
It is particularly tempting to be vague about timetables for cutting carbon dioxide (CO2) emissions as countries have failed to explain how lost nuclear capacity could be matched by a ramp-up in carbon capture and storage (CCS), which remains untested on gas and coal-fired power.
The temptation to delay decisions - and development of CCS - is especially strong as the consequences of phasing out nuclear will be felt mostly after 2020 as ageing plants are retired.
Several developed countries have announced plans for shifting away from or phasing out nuclear power, including Germany, Japan, Belgium, France, Italy and Switzerland, but none have formal, binding CO2 targets after 2020.
The most probable outcome is that interim CO2 targets will continue to be weak or to be broken, as unabated gas and coal power generation is used to replace lost nuclear capacity.
The European Commission said last December that all fossil fuel power plants should be fitted with expensive CCS from around 2030, if the European Union is to slash emissions by the middle of the century.
"CCS contributes significantly towards decarbonisation in most scenarios, with the highest penetration in case with nuclear constraints," it said in its "Energy Roadmap 2050".
CCS is meant to trap carbon emissions from fossil fuel flue gases and pipe them underground, but is still untested at a commercial scale on power plants partly because it adds at least $1.5 billion to the upfront capital cost per gigawatt of electricity generating capacity.
The alternatives are either to eliminate fossil fuels except as back-up for renewable energy, or else to relax medium-term carbon emissions targets, most of which are only aspirational and therefore politically feasible to downgrade.
The impact on unabated gas-fired power of ambitious carbon emissions targets is being debated in earnest only in Britain, which is alone in having legally binding CO2 targets beyond 2020.
Other countries are content to announce firmer plans for nuclear power in the 2020s and beyond, but not for carbon.
Coal-dependent Poland in June even voted against allowing the European Commission to propose a 2030 carbon emissions target, alone against the EU's other 26 member states.
The Commission will now prepare a discussion paper which has no timeline yet, although Energy Commissioner Guenther Oettinger suggested last December that a decision should be made by 2014 on 2030 goals.
CARBON TARGET FOR 2030
French President Francois Hollande last Friday called for deeper cuts in European Union CO2 emissions as he confirmed plans to scale back nuclear power to half of the country's power generation, by 2025, from three-quarters now.
Hollande recommended a target for a 40 percent cut in European Union carbon dioxide (CO2) emissions by 2030, but did not specify a French national target.
That echoed a European Commission impact assessment, attached to the energy roadmap last December, which suggested energy-related carbon emissions cuts of 38-41 percent by 2030, below 1990 levels.
Japan's government has backed a withdrawal from nuclear, if not a complete exit, by applying a 40-year limit on the lifetime of reactors, which means most would shut down by the 2030s.
Tokyo also last week suggested a goal to cut greenhouse gas emissions by 20 percent by 2030 compared with 1990 levels.
That is less ambitious than Japan's present target to cut emissions by 25 percent a decade earlier, by 2020, which was conditional on a global climate deal that is now out of sight.
Unlike European countries, therefore, Japan may be happy to acknowledge that reducing or phasing out nuclear will come at the expense of climate targets.
Germany was the first country to react to Japan's Fukushima crisis, deciding completely to abandon nuclear power in a step-by-step process that is to culminate in 2022.
Berlin has voluntary targets to cut carbon emissions by 55 percent by 2030 over 1990 levels.
NUCLEAR VERSUS CARBON CAPTURE
Both the European Commission and the International Energy Agency have made it clear that most fossil fuel power generation would have to apply CCS from around 2030 to meet ambitious greenhouse gas cuts, especially in a scenario with less nuclear power.
But the EU is way off the target to deploy 10-12 commercial-scale CCS power plants by 2015, as originally envisaged, with none under construction yet and plans announced in July for just two to three using a fund raised from auctioning emissions permits.
In the "low nuclear case" set out in its World Energy Outlook late last year, the International Energy Agency modelled an arbitrary scenario where the world's nuclear capacity was barely half that expected under present policies.
It found that staying on track to meet ambitious targets for reducing carbon emissions would still be possible, but only where CCS was "very widely deployed by 2035".
Britain will provide a first test of these energy choices, in a country that has encouraged new nuclear power, with the government promising a gas strategy before year-end.
Its climate advisory panel, the Committee on Climate Change, has proposed emissions cuts of 60 percent by 2030, plus an almost zero carbon grid, and gas-fired power limited to operations which cut carbon using CCS or as back-up to renewable energy.
The Committee last week wrote to Liberal Democrat climate and energy minister, Edward Davey, saying: "Extensive use of unabated gas-fired capacity ... without carbon capture and storage technology (CCS) in 2030 and beyond would be incompatible with meeting legislated carbon budgets."
Davey replied: "After 2030 we expect that gas will increasingly be used only as back up, or fitted with Carbon Capture and Storage technology," not quite meeting the Committee's expectations.
Meanwhile, Conservative finance minister George Osborne appears much less keen, announcing gas investment tax cuts in July, and adding: "The government is signalling its long-term commitment to the role it (gas) can play in delivering a stable, secure and lower-carbon energy mix."
The signs therefore are of a fudge, where the government will avoid fixing a date to mandate CCS with gas-fired power, or a target for grid carbon intensity in 2030.
That would be consistent with global trends where such decisions are avoided for a decade or more, implying more gas and coal, and therefore more carbon dioxide.