The Intergovernmental Panel on Climate Change (IPCC), a U.N. organization of international researchers and scientists, conducts tests and assesses possible impacts on the environment, compiling a report every five years since 1990.
The report compiled by one of its working groups in February concluded that it was very likely that man-made greenhouse gas emissions are responsible for the global rise in temperature since the mid-20th century.
It is now believed that such emissions could be adversely impacting the warming of the ocean, rises of average land temperatures and escalating wind patterns, among other changes.
Using scientific data on the past, the IPCC is studying a number of scenarios to examine how such changes could impact society, in an effort to find appropriate measures to minimize the risk.
In 1972, the U.N. Conference on the Human Environment was held in Stockholm under the motto of "Only One Earth." In the years following the conference, the U.N. Environment Program was launched, while the Ramsar Convention and Washington Convention were implemented, in addition to the Vienna Convention for the Protection of the Ozone Layer.
The 1990s saw more active movements to tackle climate change, most prominently with the adoption of the Kyoto Protocol to the U.N. Framework Convention on Climate Change.
The administration of U.S. President George W. Bush, however, has not ratified this treaty. But following Russia's ratification, the pact was brought into force in 2005.
There have been twists and turns surrounding the pact due to national interests and economic issues. But if we look at the drive in the three decades since 1972, it is unmistakable that a movement to tackle global warming, climate change and various other environmental issues has been gathering pace.
Under the protocol, Japan pledged to cut its greenhouse gas emissions by 6 percent from its 1990 level by 2010. We now know this is a hard goal to achieve because the nation's level of gas emissions has been increasing instead.
Under such circumstances, both the public and private sectors are reviewing measures. The level of emissions from the industrial sector has stopped growing since 1990, while, on the other hand, figures from the transportation sector and households have greatly increased.
How we are going to deal with such increases is an important aspect to be discussed. The government has plans to meet the goal with detailed targets and currently is reviewing them one by one to examine what is feasible and what is not.
For example, for the industrial sector, the number of energy-saving products to be manufactured can be clearly specified. For the household category, however, the government cannot force consumers to replace vehicles, air conditioners and other home electrical appliances with new energy-saving products. Therefore, how the government proceeds in this respect will be the key to the future.
Regarding international cooperation, the protocol proposed three mechanisms with which developed countries, such as Japan, can try to meet their emission targets, such as by introducing technologies to cut carbon dioxide and greenhouse gas emissions in other countries.
As for the post-Kyoto Protocol period, scientists have made various proposals. Actions to protect the environment should be taken at the global level. But unfortunately, the United States has not ratified the protocol, while developing nations have not set numerical targets for greenhouse gas emissions.