Rapid industrialization in the East Asian countries has helped in achieving
economic growth. Along with industrialization, primary energy consumption
has also rapidly increased in East Asia. In 2002, total primary energy
consumption in East Asia was 2.5 billion tons (oil equivalent). The major
energy source in East Asia is coal, accounting for 38% of the total in
2002. Oil and natural gas follow at a rate of 33% and 8.7% respectively.
The combustion of these fossil fuels is the main source of air pollutants
such as sulfur dioxide and nitrogen oxides released into the atmosphere.
East Asia’s total primary energy consumption in 2030 is estimated to be
4.7 billion tons (oil equivalent), twice large than in 2002 (international
Energy Agency (IEA), World Energy Outlook 2004). If there is no efficient
control, the emission of air pollutants will also increase.
Sulfur and nitric acids are recognized as major causes of atmospheric acidification.
Sulfur dioxide and nitrogen oxides emitted from the burning of coal and
oil react in the atmosphere to form sulfuric acid and nitric acid that
are deposited on the earth. Sulfuric acid is one of the most important
components used to evaluate acid deposition. In some major cities in East
Asia the annual deposition of sulfate amounts to more that 100 kg/ha. Sulfuric
acid is not only deposited with precipitation in the cities but also transported
together with sulfur dioxide and sulfate as well as other acids to surrounding
areas and may affect our natural ecosystems.
Acid deposition can cause various effects on the ecosystems through acidification
of soil and waters as well as damage to buildings and cultural heritage
through corrosion of metals, concrete and stone. In order to assess the
adverse effects on the ecosystem, it is necessary to identify dose-effect
relationship of acid and eutrophic substances in environment. It is also
important to quantify the effects on ecosystems, estimate the necessary
amount of reduction of emission, and consider the most cost-effective policy
options. Determination of emission reduction target may require the identification
of the threshold level of acidic and eutrophic substances that do not cause
any adverse effect on ecosystems.
Acid deposition is not limited by national boundaries and therefore cooperation
at the regional and international level is required to effectively address
this problem. In Europe, it was successfully achieved through the activities
under the Convention on Long-Range Transboundary Air Pollution (CLRTAP).
As pointed out in Agenda 21 adopted by the United Nations Conference on
Environment and Development in June 1992, "the programs (in Europe
and North America) need to be continued and enhanced, and their experience
needs to be shared with other regions of the world". The Acid Deposition
Monitoring Network in East Asia (EANET) was established as a regional cooperative
initiative to promote efforts for environmental sustainability and protection
of human health in the East Asian region.
