The Cabinet approved a bill Tuesday to revise the energy-saving law, aiming to cut at least 5 million more tons of carbon dioxide emissions by toughening rules on the commercial sector, including office buildings and convenience stores. The revision is the government's latest effort to meet Japan's Kyoto Protocol target of slashing greenhouse gas emissions an average of 6 percent from 1990 levels between 2008 and 2012, officials said. The government is seeking to put the revised law into effect in April 2009. Compared with the industrial sector, energy consumption in the commercial and transportation sectors has increased rapidly. But the two sectors have been slow to reduce carbon dioxide emissions. If the law on the rational use of energy is revised, about 50 percent of operators in the commercial sector that are using energy equivalent to more than 1,500 kiloliters of crude oil annually will be required to report carbon dioxide emissions to the government, up from the current 10 percent, the officials said. The current law mainly requires factories to calculate and report their emission levels, but not, for example, corporate head offices, operators of convenience stores, hotels and hospitals. In contrast, about 90 percent of energy used in the industrial sector is already covered by the law, according to the officials. The government hopes to stem greenhouse gas emissions in the commercial and residential sector, they said.