Japan's greenhouse gas emissions rose to a record high in the year to March, putting the world's fifth-largest carbon dioxide producer at risk of an embarrassing failure to achieve its Kyoto target over the next four years.

The increase of 2.3 per cent last year, largely due to the closure of Japan's biggest nuclear power plant after an earthquake, will ratchet up the pressure for it to give up its efforts to control emissions through voluntary measures and adopt tougher limits on industry like the EU and Australia.

With developing countries already questioning Tokyo's political will to rein in emissions and top CO2 polluters China, the US and India free from Kyoto's 2008-2012 targets, Japan's actions will be seen as a milestone as governments struggle to agree on a successor to the protocol next year.

Emissions rose to 1.371 billion metric tons of CO2 equivalent in the Japanese fiscal year through March, after a 1.3 per cent decline the previous year, Ministry of the Environment data showed yesterday.

Analysts said immediate action was called for if Japan was to cut emissions by the estimated 13.5 per cent needed to hit its 2008-2012 target under Kyoto of just under 1.2 billion tons, down six per cent from 1990 levels.

"We immediately need a set of effective policies to drive a change towards a more climate-friendly society," said Tetsunari Iida, executive director of Tokyo's Institute for Sustainable Energy Policies (ISEP), an environment policy NGO.

Unlike the EU, Japan has been reluctant to set a mandatory cap or a carbon tax on companies' emissions. Steelmakers and other manufacturers resist such caps, saying they would hurt their products' worldwide competitiveness.

The task of cutting emissions may grow even harder with the world tilting toward what may be its worst recession in decades, one that may divert governments' focus away from climate change and the trillions of investment dollars required to stem it.

Although Japan is set to review next year its current measures, based on voluntary pledges on emission cuts across major industries, that could be too late, analysts said.

A rise was widely expected after the world's biggest nuclear plant, run by Tokyo Electric Power Co (TEPCO), had to suspend operations following a July last year earthquake, forcing utilities to meet demand by burning more coal, oil and natural gas, all of which emit far more greenhouse gases.

The plant is expected to remain shut until beyond next March.

While Japan's utilities have stepped up their buying of UN carbon offsets, yesterday's data suggests they may have to buy more if Japan is to meet its global pledge, potentially driving up global carbon credit prices.