Figure 1-2-6 Trends in the World's Energy Supply (By Region)

Source: Created by the Ministry of the Environment, based on information from the IEA’s “Energy Balances of OECD Countries 2010” and “Energy Balances of Non-OECD Countries 2010”

Figure 1-2-7 Trends in Concentrations of CO₂ in the Atmosphere and CO₂ Emissions from Energy Sources

Sources: $ CO_{2} $ concentration: NOAA/ESRL and the US's Oak Ridge National Laboratory

$ CO_{2} $ emissions from energy sources: IEA 2010 ( $ CO_{2} $ Emissions from Fuel Combustion 2010)

It is believed that this increase in $ CO_{2} $ concentration is a factor of the increase in world temperature. Over the long term the world's annual average temperature has risen by a ratio of approximately 0.68 degrees centigrade per 100 years, and temperatures were high particularly in the late 1990s. In 2010, the world's temperature anomalies of the annual terrestrial and aquatic average surface temperatures, in other words, the average temperature minus the 30-year average from 1971 to 2000, was +0.34 degrees centigrade. This was the second highest value since observation started in 1891. Further, the average temperature in Japan in the summer of 2010 was the highest in the 113 years since observation started in 1898. We think this was caused not only by high atmospheric pressure and a cold air mass from the Sea of Okhotsk during that summer, the powerful high pressure from the Pacific Ocean which covered Japan after the rainy season, and effects from the El Niño phenomenon, but also by effects of global warming due to the increase of greenhouse gases such as carbon dioxide.

In this way, population increase and economic growth will lead to an increase of energy consumption in society and the economy, and the increase of carbon dioxide concentration caused by increase of energy consumption is a factor that places an environmental impact on the Earth in the form of global warming.

## (2) Consumption of Biomass Energy and Loss of Forest Resources

Since long ago, forest resources have supported people’s daily lives. They served as energy in the form of fuel wood, as well as timber for commercial logging.

In recent years attention has been focused on the use of biomass resources as alternative energies to replace oil and other non-renewable resources. Around the world, there has been an introduction of such resources, mostly bio-fuels obtained by refining plant-derived oil such as that from grains with high ratios of sugar and palm oil.

As for consumption of fuel wood and coal, a total of 3.4 billion $ m^{3} $ of forest are cut down annually in the world, and approximately half of that is consumed as fuel wood. This logging amount is approximately the same as Japan's entire natural growing stock of forests of 1.8 billion $ m^{3} $ , and it places a significant impact on forest resources on a global scale. In particular, the ratio of use as fuel wood is high in Africa, Asia, and South America, where it makes up approximately 50 to 90 percent, as compared with Europe and North and Central America, where it makes up approximately 10 to 20 percent (Figure 1-2-10). Especially in Africa, due to poverty, forests are cut down excessively for fuel wood and to develop agricultural land.

As for the world’s bio-ethanol production, 74 billion liters were produced in 2009, mainly in Brazil and the US, mainly from corn or sugarcane. As for bio-diesel, 15 billion liters are produced annually mainly in the EU, mostly from rapeseed. Production of oil palm, which is drawing attention as a source for bio-diesel, is increasing mainly in Malaysia and Indonesia. The land area for producing the palm trees that are used to manufacture palm oil has increased from 3.26 million ha in 1970 to 14.62 million ha in 2008, through conversion of tropical forests (Figure 1-2-11).

Additionally, with growing demand for food in recent years there is a trend of agricultural land area expanding and forest land area decreasing, primarily in tropical