Japan is to introduce a trial emissions cap-and-trade scheme from this autumn as part of a major new climate change strategy designed to cut emissions by up to 80 per cent on current levels by 2050.

The strategy was unveiled yesterday by prime minister Yasuo Fukuda in a move designed to bolster the country's green credentials ahead of its hosting of the Group of Eight summit of industrialised nations next month.

Fukuda said the country would aim to cut emissions by between 60 and 80 per cent by the middle of the century and while exact details of the proposed cap-and-trade scheme remained sketchy, he said it would seek to include "as many sectors and companies as possible".

Coming just days after the US Senate blocked proposals for a similar cap-and-trade scheme the move will be seen as a major boost to supporters of carbon trading, who argue it represents the most cost effective means of curbing emissions.

Fukuda said Japan would also aim to raise the proportion of energy it generates from nuclear, solar, wind and hydro power from 40 per cent to over 50 per cent and confirmed that the government would consider imposing a new environmental tax on emissions.

Environmentalists offered a mixed response to the move, welcoming the new targets but criticising the failure to set a formal target for 2020 and the decision to set the base line from the current year as opposed to 1990.

Fukuda countered that an interim target would be set in the future, indicating that Japan could cut emissions by 14 per cent by 2020.

In addition, he confirmed plans for Japan to contribute $1.2bn (£614m) to a multi-lateral climate change designed to fund transfer of clean technologies to developing economies and also supported by the US and the UK.

The moves will significantly strengthen Japan's negotiating position ahead of the G8 meeting next month where it is expected to push for an agreement that member countries will push for a halving of global emissions by 2050.