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Japan steps up adaptation measures to deal with global warming

Last modified January 31, 2008 12:05

With global warming intensifying, a broad range of impacts has been reported around the world, and Japan has been no exception. Humanity must take two types of measures to reduce the impacts of global warming: mitigation and adaptation.


With global warming intensifying, a broad range of impacts has been reported around the world, and Japan has been no exception. Humanity must take two types of measures to reduce the impacts of global warming: mitigation and adaptation.

Mitigation measures aim to slow the pace of global warming by reducing the emissions of greenhouse gases, the main cause of global warming, in order to prevent further increases in the concentration of greenhouse gases in the atmosphere. Such measures are essential, of course, but there is a time lag before their effects appear.

Meanwhile, adaptation measures aim to reduce the impacts of global warming by adapting society and the economy to a warmer climate, based on the recognition that a certain amount of global warming will be inevitable. Those measures could be described as "treating the symptoms" --symptoms like rising temperatures and sea levels.

The examples of realistic and effective adaptation measures include designing and constructing buildings with future warming in mind, for example, by including balconies, sun shades and natural ventilation systems. As well, in anticipation of decreases in available water resources due to drought and other impacts of global warming, precautionary measures can be taken against water shortages by introducing water-saving devices and water-loss control systems.

In the past, many people had the view that only mitigation measures should be considered, because consideration of adaptation measures cause people to abandon efforts to fight global warming. Today, however, the impacts of climate change are already being observed, so there is a growing awareness that while humanity should still take steps to fight global warming, it should also adapt itself to global warming.

The impacts of global warming are already evident all over Japan and elsewhere. For example, since the 1980s, the number of days with maximum daytime temperatures over 35 degrees Celsius has increased over the last 30 years, as has the number of torrential rainfall events. Cherry trees bloom 4.2 days earlier (national average) than they did 50 years ago. In 2000, the leaves of maple trees changed colors in autumn about two weeks later than in 1953. These signs of the changing of seasons have shifted so much that even non-experts notice that something strange is occurring.

There have been reports about the impacts on various ecosystems in Japan as well. For example, spiders native to tropical and subtropical areas can now be found in Japan. Butterflies that were once found only in southern Japan can now be spotted in the Kinki area (mid-western Japan), suggesting that their habitat is moving toward the north. In the sea, the area of coral colonies has been decreasing due to large-scale coral bleaching caused by sea water warming.

Signs of increasing impacts on agriculture are also evident. With average temperatures higher than before, there has been a drop in the quality of rice, staple food for the Japanese, due to the failure to ripen properly, damage from insect pests, and so on. Particularly in the Kyushu Island, which lies south of Honshu, the main island of Japan, the top-grade rice has dropped from 72 percent of harvests in 2001 to 30 percent recently. Among 47 prefectures in Japan, 39 have reported a deterioration of rice quality.

According to the survey by the National Institute of Fruit Tree Science, all prefectures in Japan have identified at least one impact of global warming on fruit trees, and that vegetables and flowering plants are being affected by global warming.

Besides these actual impacts, experts are concerned that various negative impacts will occur in the future. On January 8, 2008, the Ministry of the Environment announced its prediction that Japan's average annual temperature would increase by up to 4.7 degrees Celsius at the end of this century compared to the one hundred years earlier. The National Institute for Environmental Studies predicts that precipitation will increase in almost all regions of Japan. The number of days with maximum daytime temperatures of 30 degrees Celsius or higher as well as the number of days with precipitation over 100 millimeters per day are also expected to rise.

If sea levels rise by one meter due to global warming, Japan will lose much of its tidal wetlands, in addition to 90 percent of its sandy beach area. Not only that, the industrial and urban areas in coastal regions will feel large impacts, as it is predicted that in Osaka (Japan's second largest city), an area from the city's northwest section down to Sakai city will be submerged, and the same would happen to four wards of Tokyo (Koto, Sumida, Edogawa and Katsushika) .

Negative impacts on public health are also expected as the habitat of mosquitoes that transmit dengue fever would spread as far north as Hokkaido, the northern island in Japan, by the end of this century.

Huge impacts will be felt by Japan's agriculture as well. The rising average temperatures will boost evaporation from rice paddies and rice plants by about 20 percent, so farmers in the northern and central part of Kyushu Island are likely to experience water shortages. Areas suitable for the production of apples and mandarin oranges are likely to change. Tomatoes, green peppers and cabbages, are also predicted to exhibit negative impacts, including lower yields, sunlight-caused discoloration and spoilage, and cabbage may not grow properly.

Meanwhile, it is predicted that blights triggered by high temperatures will occur more frequently throughout Japan or break out further north than normal. For example, there is a concern that the areas vulnerable to rice blast disease could shift to the north. With the earth's climate getting warmer, the number of agricultural pests and their frequency of occurrence will also increase, and more pests are likely to survive the winter. Warmer winters are also expected to adversely affect vegetable and fruit production; for example, an increasing number of fungus and bacteria causing rust disease on Welsh onions will be able to survive the winter.

Higher temperatures of coastal waters in winter could reduce Alaska pollock fish catches. Global warming may lead to the loss of the current fishing and spawning grounds for other marine species as well.

Although the Japanese government was until now focusing almost solely on measures to mitigate global warming, it is now beginning to acknowledge the importance of studies and actual measures to adapt to global warming already under way.

It has given particular attention to adaptation in the agricultural sector, through studies on plant breeding, cultivation methods, and so on. The Japanese Ministry of Agriculture, Forestry and Fisheries announced a comprehensive anti-global-warming strategy on June 21, 2007, stating that it will proactively promote global warming adaptation measures. The ministry announced its short-term adaptation measures and future tasks, considered on the basis of the latest research and development findings for 13 categories of farm products, including rice and soy beans.

Adaptive Measures Involving 13 Agricultural Products Announced to Combat Global Warming

In October 2007, the Ministry of the Environment also established an ad hoc committee to begin studying the country's possible global warming adaptation measures. Within the committee, task forces are to be set up in seven areas--food, ecological systems, disaster prevention, water resources, health, urban life, and aid to developing countries. Each group will discuss measures and studies to promote, considering conditions expected around the years 2020 to 2030. Until now, studies regarding adaptation measures were fragmentary, but by promoting better information sharing, the ministry aims to establish more effective adaptation measures.

Adaptation will not necessarily help society cope with all of the projected effects of climate change. However, given the fact that global warming is already upon us, it is essential to step up such measures in order to sustain our society and economy in warmer climates. For instance, when designing new buildings, it is important for us to take into consideration the higher temperatures and other foreseeable impacts of global warming. There is no doubt that the need and demand for adaptation measures will grow, as the impacts of global warming become increasingly apparent.

When considering these matters, it soon becomes clear that adaptation measures will be expensive, as in the case of raising the height of coastal dikes, for example. It is all the more important, therefore, to strike a balance between adaptation and mitigation. Humanity must carefully allocate its resources--measured in terms of money, human resources, public attention, and so on--not only into the obvious solutions but also into greater efforts to cut greenhouse gas emissions, as those are the ultimate steps needed to mitigate global warming.

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