Association, Inc.

Issue No. 1, 2007

An "integrated approach" to the reduction of CO2 emissions in Japan

In August 2006 the European Commission published its sixth annual assessment of the voluntary commitments of JAMA, ACEA and KAMA to CO2 reduction.  JAMA has since reaffirmed its determination to reduce CO2 emissions from new passenger cars to an average of 140g/km by 2009 as per its commitment, but would like to emphasise that further significant CO2 reductions in the road transport sector cannot be achieved through the efforts of auto manufacturers alone.  An integrated approach is required instead, one that takes into account vehicle manufacturers, government, and vehicle users.

In Japan such a strategy has already been factored into the government-established 2010 reduction targets for CO2 emissions in the domestic road transport sector.  It is referred to as the "three-in-one approach" because it comprises the three elements of greater fuel efficiency, smoother traffic flow through road infrastructure improvement, and the adoption of eco-driving (including the use of clean-energy vehicles and better driving practices) by vehicle users.

The diagram below illustrates this three-in-one approach which represents the trilateral efforts of industry, government and automobile users in Japan.

Greater fuel efficiency

The Japanese government has targeted a 21 million-ton cut in road transport CO2 emissions by 2010 through greater automotive fuel efficiency.  JAMA member companies are making strenuous efforts to meet this target and have already introduced to the market a wide range of models with improved fuel economy.  They are also developing advanced clean-energy (alternative-fuel) vehicles, including hybrids and vehicles that run on natural gas.

The government, meanwhile, is applying a "green tax" scheme of incentives to promote the more widespread use of vehicles with improved fuel economy and clean-energy vehicles (including hybrids).

The 2010 CO2 reduction target for Japan’s road transport sector will be met, JAMA believes, on the basis of the combined efforts of government and the auto manufacturers together with the cooperation of the driving public.   

Road infrastructure improvement

The Japanese government is seeking a reduction by 2010 of 28.3 million tons of road transport CO2 emissions through improved traffic flow.  Traffic congestion can be alleviated through road infrastructure improvements, including expansion of the road network.  A trial study conducted by the Japan Automobile Research Institute (JARI) has confirmed that improving traffic flow is an effective means of reducing automotive CO2 emissions.


Japan’s government estimates that 1.3 million tons of CO2 can be cut by 2010 through the adoption of sound eco-driving practices by motorists. 

Driving habits have a significant impact on automotive fuel efficiency.  Efforts by drivers to conserve energy will therefore contribute to greater fuel economy and reduced CO2 emissions.  Eco-driving includes such practices as:

JAMA believes that sound eco-driving habits must be further encouraged by the relevant authorities.  For its part, JAMA will continue to develop driver education programmes and implement public awareness campaigns that promote the adoption of eco-driving by vehicle users.