By Jonathan Head
BBC News, Tokyo
As the country which hosted the 1997 Kyoto conference on climate change, Japan has always been one of its strongest advocates, ratifying the treaty in June 2002.
The international climate treaty was negotiated in Kyoto, Japan, in 1997
Like other industrialized countries, Japan has committed itself to reducing its carbon emissions substantially by the year 2010 - in Japan's case to 6% less than 1990 levels.
But despite its good intentions, Japan's performance has been embarrassingly weak - carbon emissions have actually increased by nearly 8%.
At this rate it has little chance of meeting the obligations it signed up to, sending a dispiriting signal to other Asian countries which are likely to become some of the biggest greenhouse gas producers over the next decade.
One of Japan's difficulties is that it was already very energy-efficient at the time of the Kyoto treaty. The country has few natural energy sources of its own, making its vital manufacturing industries highly dependent on imported fuel.
So when the two oil shocks of the 1970s pushed up prices, Japan set about using its technological ingenuity to cut down on its fuel consumption.
There was a huge investment in nuclear power stations; Japan relies on nuclear power for one third of its electricity production.
Household appliances have continued to become more and more efficient, and the government has drawn up a law that would require manufacturers of air-conditioners, the heaviest drain on household electricity, to design units that consume 20% less power by 2010.
Prime Minister Junichiro Koizumi ordered air-conditioning in government offices to be set at a sweltering 28 degrees
Solar panels are more widely used in Japan than anywhere else; households equipped with them can sell back their surplus electricity to the national grid.
And Japanese manufacturers, from steel, to cars, to electronics, are some of the most energy-efficient in the world.
Which means making further cuts in emissions will cost Japan a lot more money per tonne of carbon than it will cost the USA or EU.
No surprise then that Japan has shown great interest in Kyoto treaty components such as the Clean Development Mechanism (CDM) and Joint Implementation, which allow businesses in industrialised countries to buy carbon credits from countries which will exceed their Kyoto targets or are not bound by them, or to earn credits by investing in carbon-reducing projects in countries where it is easier and cheaper to achieve new efficiencies.
For example, the Tokyo-based power company Tepco is investing in a cassava-processing plant in Thailand, installing furnaces to burn the methane, a greenhouse gas, produced by the plant for power generation.
More than forty such CDM projects by Japanese companies have been approved by the Japanese government since 2002.
It is now drawing up legislation to ensure this carbon trading is properly accounted, and a Dutch company is planning to establish the country's first "carbon exchange", where carbon credits can be traded.
The culture of energy-efficiency is impressively deep-rooted here. Last summer Prime Minister Junichiro Koizumi initiated a fashion known as "cool-biz", when he ordered air-conditioning in government offices to be set at a sweltering 28 degrees, and told officials and members of parliament to abandon their jackets and ties.
The reverse has happened this winter; some town councils have adopted a "warm-biz" theme, turning off the heat and working at their desks in blankets and overcoats.
Japan already makes some of the world's most energy-efficient cars, and is adept at persuading American drivers, the world's greatest gas-guzzlers, to buy them.
Its manufacturers are ahead of everyone else in developing revolutionary fuel-cell engines, which produce no emissions, although they are still far too expensive for mass-production.
Even with all this, and the system of carbon credits, there is every likelihood Japan will fail to meet its Kyoto commitments.
But it will not be for want of trying.