## Figure 1-4 Greenhouse Gas Emissions (Other than $ CO_{2} $ Emissions Resulting from Energy Use)

# 2 Conservation of the Global Environment, the Atmospheric Environment, the Water Environment, the Soil Environment, and the Ground Environment

## (1) Current status of the earth’s environment

## A Depletion of the ozone layer

CFCs, HCFCs, halons, methyl bromide and some other substances have been found to be depleting the ozone layer. There is concern that the depletion of the ozone layer may increase the amount of harmful ultraviolet radiation (UV-B) reaching the earth, leading to increased damage to human health such as skin cancer and cataracts, as well as hindering the growth of plants and plankton. Many of these ozone-depleting substances are also powerful greenhouse gases and promote global warming.

Ozone-depleting substances have been regulated by the Montreal Protocol on Substances that Deplete the Ozone Layer (hereinafter referred to as the "Montreal Protocol") since 1989. As a result, the atmospheric (troposphere) concentrations of CFC-12 which is a main ozone-depleting substance, has nearly leveled off in the mid-latitude Northern Hemisphere since the second half of 1990s, and the total concentrations of ozone-depleting substances within the stratosphere have tended to decline.

However, ozone in the atmosphere has massively decreased from 1980s to the first half of 1990s, and it is still showing a decreasing trend.

The area of the ozone hole over Antarctica in 2007 was found to be the third smallest scale after 2002 and 2004 over the past decade (since 1998) (Figure2-1). At present, no downward trend in the size of the ozone hole area can be observed. The ozone layer over Antarctica is still in critical condition. According to the Scientific Assessment Panel of the Montreal Protocol on Substances that Deplete the Ozone Layer (2006), ozone hole is considered to be regenerated for the next several decades, and the ozone layer over Antarctica is expected to return to the level of before 1980 by around the mid-21st century.

In addition, the atmospheric concentrations of HCFCs, that are replacing CFCs internationally, and HFCs, which gases have a high greenhouse effect although not depleting the ozone layer, have tended to increase.

Figure2-1 Changes in the Size of Ozone Hole over Antarctica

## B Acid deposition and dust and sandstorms

## (a) Acid deposition

Impacts on fish and others due to acidification of lakes, reservoirs and rivers brought about by acid deposition, and impacts on forests, buildings and cultural assets due to acidification of soils are of concern. A characteristic of acid deposition is that it can affect areas located several thousand km from the source of the causing substances, and is a transboundary wide range phenomena.

In Japan, long-term acid deposition monitoring and research on its effects has been carried out since FY1983. A brief summary of the most recent monitoring results of the recent five years (FY2003 to FY2007) compiled in 2009, is as follows:

1. Acid deposition has still been observed nationwide (Mean value of pH4.68).

2. Inflow of air pollutants from continents to the area facing the Japan Sea and western Japan were indicated and nationwide impacts by transboundary ozone pollution and dust and sandstorms (DSS) were indicated.

3. Regarding the impacts on the ecosystem, ecological damage such as declining trees, due to acid deposition and acidification of lakes and reservoirs were not confirmed.

4. In soil surrounding areas of lake Ijira in Gifu Prefecture where acidification has been recognized, acidification of soil and mountain streams were