On 30 April, the Ministry of the Environment (MoE) announced the final data regarding the amount of emissions of greenhouse gases (GHG) in the 2007 fiscal year. According to MoE, the amount of GHG emissions in the 2007 fiscal year was approximately 1.37 billion tons (CO2 equivalent), exceeding the amount of GHG emissions in the 1990 base year by 9.0 percent and exceeding the amount of those in the 2006 fiscal year by 2.4 percent. This was the worst result for Japan in terms of GHG emissions.
It was reported that such a surprisingly high increase in GHG emissions was significantly affected by the suspension of operation of the Kashiwazaki-Kariwa nuclear power plant operated by Tokyo Electric Power Company (TEPCO) in the Niigata prefecture as most of CO2 emissions in Japan are energy-origin CO2 emissions.
The Kashiwazaki-Kariwa nuclear power plant has seven units, generating a total electrical output of 8,212 MW, making it the largest nuclear plant in the world by net electrical power rating. Though Japan heavily depended on the nuclear plant, it had to stop the operation because of the Niigata Chuetsu earthquake in July 2007 because the Kashiwazaki municipal government ordered TEPCO not to start the operation of the plan until its safety was confirmed and the Ministry of Economy, Trade and Industry (METI) gave TEPCO a similarly order. Consequently, thermal power stations, emitting more GHG, had to operate more, resulting in increase in CO2 emissions.
Thus, in order to reduce CO2 emissions and avoid electricity shortage in the summer season, the Japanese Government and TEPCO have strongly wanted to restart the operation of the plant. Then, on 7 May, Hirohiko Izumida, the Governor of the Niigata prefecture, announced that he acknowledged a request from TEPCO to restart its operation. Though TEPCO consequently started the trial operation of Unit 7 of the plant on 9 May, problems were found in its reactor core isolation cooling system in its trial operation. As a result, though it was expected that the plant was going to start its operation in the end of June, it became unclear whether the plant was able to do so.
If the operation is delayed, Japan again would need to heavily depend on thermal power stations in this summer and CO2 emissions would increase compared to the condition in which the nuclear plan could operate. However, it may be apparent that the safety of the nuclear plant has not been confirmed. As well as problems of the plant found in the trial operation, it has been still questionable whether the plant is really earthquake resistant. Indeed, constructing nuclear plants in Japan, where a huge number of earthquakes happen, seems really scary. As Japan seems most unsuitable for constructing nuclear plants considering earthquakes, Japan may be one of the countries that should immediately increase renewable energy production in order to reduce CO2 emissions and simultaneously avoid electricity shortage.