北里大学

北里大学農医連携教育研究センター

41号

情報:農と環境と医療41号

2008/8/1
Kitasato University
Newsletter of the President Office
August 1, 2008

Newsletter: Agriculture, Environment, and Medicine No.41
 
The Proceedings of
The Fifth Agromedicine Symposium in Kitasato University
March 25, 2008
 
Global Warming:
Assessing the Impacts on Agriculture, the Environment, and Human Health, and Techniques for Responding and Adapting


 
A Message from the Symposium Organizer Tadayoshi Shiba
Tadayoshi Shiba
President, Kitasato University

I would like to offer a few opening remarks on behalf of the sponsor of this Fifth Kitasato University Agromedicine Symposium.

It has been over two years since Kitasato University first communicated the concept of agromedicine. During that time we created the Agromedicine Committee and had the committee members prepare a document titled "On the Kitasato University Agromedicine Initiative."

To disseminate information we publish Kitasato University Newsletter of the President Office "Newsletter: Agriculture, Environment, and Medicine" each month, and have already reached issue number 36.

In the way of education, we started "lectures and seminars on agromedicine" in the School of Medicine and School of Veterinary Medicine. And this April in the College of Liberal Arts and Sciences we started a course called "Liberal Arts Seminar B: Agromedicine."

In the area of research, we set up "the development of standardization methods for determining the state of heavy metal ingestion and decreasing it," and we are promoting agromedical research that transcends colleges and involves the entire university.

To benefit society, we hold these Kitasato University Agromedicine Symposia in an effort to broaden agromedicine and provide scientific information. Two years have passed since starting these symposia, during which time we have addressed contemporary issues of agriculture and medicine through the environment under the themes "Agriculture, Environment and Healthcare," "Alternative Medicine and Alternative Agriculture," "A Look at Avian Influenza from the Perspective of Agriculture, Environment, and Medicine," and "Effect of Cadmium and Arsenic on Agriculture, the Environment, and Health." We also set up a system under which the results are made into pamphlets available for purchase by anyone.
 This fifth symposium addresses the most relevant issue of our day: "Global Warming: Assessing the Impacts on Agriculture, the Environment, and Human Health, and Techniques for Responding and Adapting."

I would like to explain how we arrived at the main idea for this symposium.

Why is it that we do not give thought to the astonishing crises that humanity and civilization now face? Global warming is triggering extremely harmful phenomena in ecosystems, and Earth's biosphere has already surpassed the limit at which warming can be controlled. What is the reason that people nevertheless cannot understand this? Why is it that the United States backed out of the Kyoto Protocol, that developed and developing countries engage in political tug-of-war, and no progress is made on effective international measures to deal with global warming? Do we still lack an understanding, deep down in our hearts, of the concept that Earth is inhabited by all kinds of organisms, including human beings, from microorganisms on the small end to whales on the large end, and of the concept that these organisms are part of the "living Earth" that envelops an even greater diversity? Why don't people notice that all these crisis-like phenomena arise from our activities to produce a bounty of food and lead convenient and cultural lives? And even if they do notice, why can't they make any improvements?

But happily, in 2007 the Nobel Prize went to former US Vice President Al Gore, who had been working on the global warming issue since the 1970s, and to the Intergovernmental Panel on Climate Change (IPCC). This brought the global warming issue into the consciousness of people around the world.

The negative impacts on human livelihoods by global warming, which has become a crisis, are extremely serious. Food-related problems such as drought, salinization, and soil erosion, as well as medical problems like heatstroke, stronger UV radiation, dengue fever, and malaria all cast a dark shadow over the future of humanity. In any era, global environmental changes are intimately linked to agriculture, which provides us with food, and to medicine, which protects human health and life.

This symposium uses an approach from this perspective, and we invited speakers who have in various ways been active with the IPCC in Japan and other countries. I want to express my sincere gratitude to these speakers for kindly agreeing to appear today.
An Historical Overview of the GAIA Hypothesis and the IPCC Reports, and Global Warming in Japan Katsu Minami
Katsu Minami
Professor,KitasatoUniversity

Introduction

It was 1969 when everything changed. Like seeing oneself reflected in the surface of a river, in that year we first saw ourselves in the photographs of the blue Earth from the Apollo spacecraft. From that time we came to the realization that we cannot detach ourselves from Earth as a whole. And it seems we gained the subconscious awareness that perhaps Earth is one big living organism.
 At the same time, 1969 was a creative year when Lovelock came up with the idea that Earth is the biggest organism in the solar system (the Gaia hypothesis). His hypothesis, announced that year, stated that the biosphere has a self-regulating function with the capacity to maintain our planet's health by regulating the chemical and physical environment. Because the science and technology of the Apollo mission had developed consciously and rationally, we concentrated on seeing Earth as a whole from a bird's-eye view. This led to the formation of the Intergovernmental Panel on Climate Change (IPCC) and the participation of many scientists in climate change research, and this science and technology developed to the point of receiving the Nobel Prize.
 On the other hand, while the Gaia hypothesis is also conscious and rational, one discerns an unconscious and intuitive background to a small degree. This hypothesis has had a major influence on many engineers and scientists in every field for approaching current problems concerning Earth. As a result, physicists, chemists, medical scientists, agriculturists, meteorologists, and many other scholars cooperated in integrating their knowledge. Further, this hypothesis even advanced into fields concerning the brain and spirit, with such names as "Global Brain" (Peter Russell) and "Earthmind" (Paul Devereux). These ways of thinking have made their way far and wide, now even integrating the knowledge of science and religion.
 Therefore, in the historical background of global warming one can find conscious and rational aspects coexisting with unconscious and intuitive aspects. So here I would like to pursue "an historical overview of Gaia" and "an historical overview of the IPCC reports," and as time permits, describe some actual examples from "Global Warming: Impacts on the Festoon Islands of Japan." Further, we shall compile things that we can do right now, and consider what will happen to Japan in the way of global warming and culture.

An Historical Overview of Gaia

The concept of Gaia was disseminated widely throughout the world by the British scientist James Lovelock, who graduated from college as a chemist, earned D.Sc. degrees in biophysics, Ph.D. degree in medicine, served as a professor in a medical college, and, as a consultant for NASA's space exploration plan, participated in a project to search for life on Mars. He is also an expert at gas chromatography, and the electron capture detector(ECD) he invented has contributed greatly to environmental analyses.
 Lovelock explained that Silent Spring authorRachel Carson raised questions not as a scientist, but as an advocate, whereas he attempts to demonstrate the concept of Gaia, the living Earth, across a broad spectrum of scientific fields from astronomy to zoology.
 Lovelock has issued many books on Gaia, including Gaia: A New Look at Life on Earth, The Ages of Gaia, Gaia: The Practical Science of Planetary Medicine, The Reveng of Gaia, etc. Last year, at age 89, he published The Revenge of Gaia: Why the Earth Is Fighting Back  ̄ and How We Can Still Save Humanity. In the Japanese-language version this was translated literally as The Revenge of Gaia.
 In 1979, Oxford University Press published his book Gaia: A New Look at Life on Earth. This was published in Japanese translation in 1984. It took five years for the translation to be published.
 In 1988, W. W. Norton published Lovelock's book Ages of Gaia. This appeared in Japanese translation in 1989. We were able to read this in Japanese translation only one year later.
Lovelock's recent work The Revenge of Gaiawas issued in the original English and Japanese translation in 2006, so we were able to get the translation in the same year. The shortening time lag between the original and the translations of these 3 books bespeaks the strong interest that people have in Gaia. Further, the warming of Earth also raises people's interest in the biosphere.
 Twenty-seven years passed between the publication of Gaia: A New Look at Life on Earthand the appearance of The Revenge of Gaia. That is over a quarter century. To sum up Gaia: A New Look at Life on Earthin a few words, it is proof of the hypothesis that Earth's organisms, atmosphere, oceans, and soil make up a complex system that can be seen as a single organic whole, and has the capacity to maintain our Earth as a place suitable for life.
The Ages of Gaiawas totally rewritten on the basis of new scientific knowledge that emerged after Gaia: A New Look at Life on Earthwas written. Nine years elapsed in that time.
 In the introduction, Lovelock emphasizes that he only wants to speak for Gaia because there are far fewer people speaking for Gaia than speaking for humans. In "The Hippocratic Oath," he explains one of this book's purposes by saying that a specialized field called planetary medicine is needed, and that as its foundation it is necessary to create geophysiology.
 Especially notable about this book is this passage, which some time ago forecast an IPCC conclusion: "The health of the Earth is most threatened by major changes in natural ecosystems. Agriculture, forestry, and to a lesser extent fishing are seen as the most serious sources of this kind of damage with the inexorable increase of the green-house gases, carbon dioxide, methane, and several others coming next."
 "There is no way for us to survive without agriculture, but there seems to be a vast difference between good and bad farming. Bad farming is probably the greatest threat to Gaia's health."
 In The Revenge of Gaia, Lovelock explains that Gaia is attempting to eject human beings. He also says that there are too many human beings for Gaia to accept, and he writes that until nuclear fusion and hydrogen energy technologies become viable, the electricity that is the basis for supporting the oversize human population will have to come from nuclear fission, which has the smallest environmental burden.
 Lovelock says the critical point for global warming is a CO2 concentration of 500 ppm. If the amount of Arctic ice that melts increases, he says, the CO2 trapped in the ice will be released and further spur on warming. Here we catch a glimpse of the threshold value issue, which people do not talk about much. One must be aware of the atmospheric CO2 concentration, and the threshold value, which is determined by air temperature. Once this value is exceeded, the result cannot be changed no matter what one does. Earth has reached an unprecedentedly high temperature, and it is too late to go back.
 Tuvalu, in the South Pacific, is faced with the crisis of inundation. Will it be necessary for Japan to build sea walls to prevent the inundation of coastal plains due to expansion of seawater caused by rising air temperature? When Earth rapidly heads toward a new and sweltering state, climate change will doubtless bring chaos to political and business circles.

An Historical Overview of the IPCC Reports

The origin of the IPCC goes back to the start of research on the climate and climate change by WHO and UNEP, occasioned by worldwide extreme weather events such as heavy flooding, drought, and warm winters. As international challenges related to climate change increased, there was a rising need to comprehensively provide scientific information on climate change so that governments would devise effective policies. Against this backdrop, ideas for creating the IPCC were proposed at the 1987 WMO Congress and the UNEP Governing Council meeting. Approval and establishment of the IPCC came in 1988.
 Although the IPCC was originally founded without any connection to the United Nations Framework Convention on Climate Change (UNFCCC), because its First Assessment Report was considered outstanding for compiling and assessing knowledge on climate change, it came to be used widely as a basic reference.
 The First Assessment Report (1990) includes: Scientific Assessment of Climate Change  ̄ Report of Working Group I [WGI] (increases in greenhouse gases and their contributions to global warming are important), Impacts Assessment of Climate Change [WGII], The IPCC Response Strategies [WGIII], Climate Change: The IPCC 1990 and 1992 Assessments, and summaries for policymakers (SPMs).
 The 1994 IPCC Special Report (Climate Change) includes Radiative Forcing of Climate Change and An Evaluation of the IPCC IS92 Emission Scenarios, IPCC Technical Guidelines for Assessing Climate Change Impacts and Adaptations, IPCC Guidelines for National Greenhouse Gas Inventories, and the 1994 Special Report SPM.
 The Second Assessment Report, Climate Change 1995, includes The Science of Climate Change [WGI], Impacts, Adaptations and Mitigation of Climate Change: Scientific-Technical Analyses [WGII] (technologies for greenhouse gas reductions are important), Economic and Social Dimensions of Climate Change [WGIII], IPCC Second Assessment Synthesis of Scientific-Technical Information Relevant to Interpreting Article 2 of the UNFCCC, and Summaries for Policymakers of the three Working Group reports.
 The Third Assessment Report, Climate Change 2001, includes The Scientific Basis [WGI], Impacts, Adaptation & Vulnerability [WGII], Mitigation [WGIII], and the Synthesis Report.
 The Fourth Assessment Report, Climate Change 2007, includes Technologies, Policies, and Measures for Climate Change Mitigation; Description of the Simple Climate Model Used in the IPCC Second Assessment Report; Atmospheric Greenhouse Gases: Physical, Biological, and Socioeconomic Impacts; Impacts of Proposals for Restricting Carbon Dioxide Emissions; and Climate Change and Biodiversity.
 IPCC Special Reports include: The Regional Impacts of Climate Change: An Assessment of Vulnerability (1997), Aviation and the Global Atmosphere (1999), Methodological and Technological Issues in Technology Transfer (2000), Emissions Scenarios (2000), Land Use, Land-Use Change, and Forestry (2000), Guidance Papers on the Cross Cutting Issues of the Third Assessment Report, and Climate Changes the Water Rules: Dialogue on Water and Climate Synthesis Report.

Global Warming Impacts on the Festoon Islands of Japan

Here are some impacts of global warming on the festoon islands of Japan: Melting of permafrost (Mt. Fuji and Hokkaido); poor catches of sardines (Sardinops melanostictus) (off coast of Sanriku region); damage to rice crops (Kyushu); sea level rise (western Japan); coral damage (Okinawa); deer winter in mountain (Tochigi, Gunma, and Hokkaido prefectures); decline of alpine plants (beech forests, Callianthemum miyabeanum); reduced apple harvests (Aomori Prefecture); larger methane emissions (rice fields); northward migration of the cicada Cryptotympana facialis (Tokyo); more tropical nights (Tokyo); large outbreaks of Nomura's jellyfish (Nemopilema nomurai) (coastal areas of Japan Sea and Sanriku region); enlargement of Asian skunk cabbage (Lysichiton camtschatcense) (Oze); wetland loss (Kushiro); reduced transparency of lake water (Lake Mashu); threat of extinction for the Okinawa rail (Gallirallus okinawae) (Okinawa); loss of sand dunes and coastal erosion (Shizuoka and Chiba prefectures); major outbreaks of cyanobacteria (Ibaraki Prefecture); unusual changes in urban vegetation due to warm winters (Tokyo); and reduced numbers of the ptarmigan (Lagopus muta)in the Southern Japan Alps.

What We Can Do Right Now?

Why do our thoughts not extend to the extraordinary crises that humanity and civilization now face? Heating due to global warming is bringing about phenomena which are extremely harmful to ecosystems, and has already exceeded the level at which warming could be controlled, yet why can't people understand that?
 What can we do right now? Return carbon and nitrogen to the soil. Devote ourselves body and soul to buying green products. Decrease our desire for material things. Reduce consumption of resources and energy. Reduce pollution and waste across the board in production, distribution, and consumption. Turn our attention not only to CO2, but also to CH4 and N2O. Though we might criticize politicians, the media, and the national structure and system, we need the self-awareness that we ourselves cause global warming. Transition to and lead the way to a negative-growth economy. Cultivate thinking in which the economy is a subset of the environment, and immediately discard thinking in which the environment is a subset of the economy.

Global Warming and Culture

Won't global warming also affect the culture of beautiful Japan? Might we not expect, for example, the loss of beautiful landscapes, the loss of communities in residential areas, qualitative changes in customs, the loss of biodiversity, changes in music and poetry, and a crisis in the mental world, which is not a matter of numerical values shown scientifically? There is little doubt that we too will experience phenomena similar to the tragedy of Bhutan, where glacial lake outburst floods occur soon.
Assessment of Global Warming Impacts on Terrestrial Ecosystems, and Adaptive Techniques Yousay Hayashi
Yousay Hayashi
Pofessor, University ofTukuba Graduate
School of Life and EnvironmentalSciences

People first became aware of the global warming crisis at the 1985 Villach Conference, which adopted a declaration saying that the increase in world temperature in the first half of the 21st century will probably be a substantial one that humanity has never before experienced. Over 20 years have passed since global warming became an internationally critical issue, and now the global ecosystem is partaking of the "reality" predicted in that declaration. In recent years an international framework of the Intergovernmental Panel on Climate Change (IPCC), conferences of the parties (COP) to the United Nations Framework Convention on Climate Change, and other institutions has been established to tackle the problem of global warming, and in 2005 the Kyoto Protocol, which specifies numerical targets for greenhouse gas reductions, came into effect.. As we enter 2008, the year when the Kyoto Protocol's First Commitment Period starts, we shall see what real effect the measures to combat global warming have.
The need to reduce greenhouse gases is substantiated by the impacts of past and projected global warming. To summarize the Working Group I report of the 2007 IPCC Fourth Assessment Report, "The Physical Science Basis," the results of observations made in recent years show: (1) Warming is unequivocal, and there was an increase of 0.74°C in the global average temperature over the 100 years of observations from 1906 to 2005, (2) the average world sea level increased at the annual rate of 1.8 mm from 1961 to 2003, and there is a very real possibility that the melting of the Greenland and Antarctic ice sheets is contributing to this, (3) mountain glaciers and snow cover have dwindled in both the northern and southern hemispheres, (4) the frequency of heavy rain has increased over most land areas, and (5) there are fewer cold days and frosts, while there is a greater frequency of hot days and heat waves. Based on these facts, the report says, "Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations," thereby concluding that the increase in anthropogenic greenhouse gases is the cause of global warming.
On projections for the future, the report offers the results of warming projections based on a number of social scenarios called SRES scenarios. The main predicted changes are as follows: (1) Temperature: Over the next 20 years temperature will rise at a rate of about 0.2°C per decade. Average world temperature at the end of the 21st century will be 1.1-6.4°C higher than the annual average between 1980 and 1999. (2) Oceans: The normal value of the global average sea level from 2090 to 2099 will be 0.18-0.59 m higher than the normal value for 1980 to 1999. At the same time, the increased atmospheric carbon dioxide concentration will cause acidification of the oceans, and at the end of the 21st century the global average pH of ocean surface water will be 0.14-0.35 lower. (3) Precipitation: It is very likely that average annual precipitation will increase in high latitudes. On the other hand, in many subtropical regions average annual precipitation will decline (it is likely that the normal value for 2090-2099 will be a maximum 20% lower than the normal value for 1980-1999). (4) Changes in the polar regions: Major changes are predicted. In spite of differences among greenhouse gas emission scenarios, sea ice will shrink in both the Arctic and Antarctic. In particular, Arctic ice in the late summer will almost totally disappear by the second half of the 21st century.
Temperature and precipitation in East Asia are reported as follows: Average annual temperature is projected to rise in comparison with the normal value for 1961-1990. The normal value for 2010-2039 will be 1.3-1.5°C higher, that for 2040-2069 will be 2.5-3.6°C higher, and that for 2070-2099 will be 3.4-6.1°C higher. Precipitation is likewise projected to increase in comparison with the 1961-1990 normal value. The average value for 2010-2039 in winter (December through February) will be 5%-6% higher, that for 2040-2069 in winter will be 10%-13% higher, and that for 2070-2099 in winter will be 15%-21% higher.


Terrestrial ecosystems have in the past been affected in various ways by rapid changes in environmental conditions, and it is predicted that they will also be affected in the future. The IPCC Fourth Assessment Report (Working Group II) can be summarized as follows:

  • Flora and fauna are migrating toward the polar regions or to higher altitudes. Responses to global warming by various terrestrial species are being manifested as changes in growth stages (phenological changes), especially the earlier occurrence of springtime phenomena and bird migrations, and as lengthened growing seasons. Satellite images taken since the early 1980s show that in many regions vegetation greens earlier in spring, and that because the growing seasons of plants are longer, their net primary productivity has increased. Although there are still few cases, we are seeing the disappearance of endemic species and changes in species composition over the last 20 to 30 years.
  • The impacts of global warming on agriculture and forestry are still limited compared to other fields, but earlier crop growing seasons are clearly observed across broad swaths of the northern hemisphere. In particular, changes in crop management such as earlier planting have appeared in the higher latitudes of the northern hemisphere. In many regions, longer growing seasons are manifested as increased forestry production. Meanwhile, higher temperatures and dry conditions in other areas have combined to cause declining forestry productivity and forest fires. Agriculture and forestry have weak defenses against recent heat waves, drought, and floods.
  • By 2100, ecosystems will be exposed to the highest atmospheric CO2 concentration in the last 650,000 years, and to the highest average global temperature level in the last 740,000 years. Seawater pH will be the lowest in the last 20 million years. The combination of unprecedented changes, such as disturbances related to climate change (floods, droughts, forest fires, insect and disease outbreaks, seawater acidification, etc.) and other global-scale changes (land-use changes, population growth, excessive resource extraction, etc.), is expected to exceed the capacity of many ecosystems to adapt. When environmental conditions exceed a certain threshold of ecosystem restoration capacity, they are likely to trigger changes which cannot be undone.
  • Currently the terrestrial biosphere serves as a carbon sink, but it is thought that its effectiveness will peak and then start declining about mid-century, whereupon it will become a carbon source and aggravate climate change. An example of this is the accelerated emission of methane from the tundra. At the same time, the buffering capacity of the oceans will be saturated. Under such conditions, the concentration and emission of CO2 will be higher than at present. Land-use changes and logging of rainforests are among the factors affecting the global carbon balance.
  • Scientists think that the danger of extinction will increase if the average global temperature exceeds that since the Industrial Revolution by 2-3°C; so far 20%-30% of all species have been evaluated. Compared with conditions in the geological past, the danger of species disappearance is the highest ever.
  • A temperature increase of 2-3°C over that at the time of the Industrial Revolution and the level of atmospheric CO2 concentration underlying that increase would probably induce intrinsic changes in the structures and roles of terrestrial and marine ecosystems.
  • Results of model experiments performed on warming regions found that if the average temperatures of farming regions have moderate increases (1-3°C), then because of the concomitant increase in CO2 concentration and changes in amount of rainfall , grain yields would increase somewhat, thereby having a positive effect. But in low-latitude zones, especially tropical areas with dry seasons, many grains would yield less even at a temperature rise of 1-2°C. That would increase the danger of famine. A further temperature increase would have a negative effect on all regions.
  • Climate change will raise the number of people exposed to the danger of famine, which would in turn substantially hinder socioeconomic development.
  • It is clearly predicted that, in addition to warming occurring as a long-term trend, the increased frequency and intensity of extreme weather events will result in unstable food and forestry productivity. Recent research suggests that frequent heat waves, droughts, and floods will eclipse the impacts of warming and have detrimental impacts on crop yields and livestock production. In other words, there are concerns that negative impacts will be greater and come sooner than impacts under the average situation alone.
  • As temperatures rise, water will be strictly managed. However, for temperature increases in the range below the medium level, it is predicted that appropriate adaptation measures will result in many advantages. The effects of adaptation will be varied, ranging from only slightly alleviating negative impacts to changing negative impacts into positive ones. In grain cultivation systems, for example, adaptation such as changing cultivars or planting times could avoid 10%-15% of predicted yield declines. If converted to a temperature difference in a certain region, this corresponds to a temperature increase of 1-2°C (in equivalent to a decrease of yield) . Changing policies and systems is essential to facilitate adaptation. Adaptive techniques should be implemented in coordination with development tactics, local policies, strategies for eliminating poverty, and other such efforts.
  • Recent re-analysis of FACE(Free Air CO2 Enrichment) experiments found that at a 550 ppm concentration C3 plants realize a 10%-20% yield increase in the absence of other stresses. C4 plants had a 0%-10% increase. Estimates using a crop model under conditions of heightened CO2 concentration provided results that matched these experimental values. Recent FACE experiments found no definite productivity response in grown forest communities, but found that growth was augmented in young trees.


The IPCC reports bring together a variety of assessments on the impacts of global warming on ecosystems, and it is important to consider this matter as an urgent task from the following perspectives: First is that when multiple influences come to bear simultaneously, there are unexpected effects; second, unless one looks at the widest diversity of ecosystems possible, one will not discern the true situation. An example of the first would be the fertilization effect of raised CO2 concentration on grains (a favorable effect) actually is manifested as fertility decline (a negative effect) when it acts at the same time as temperature rise. In an example of the second, while greater insect damage due to global warming is predicted, the effect on a simultaneous increase in predators that feed on those insects could have some impact on the number of insect pests.
It is of the greatest importance to use the situations, future projections, and assessments discussed above in mitigating global warming impacts. In this connection, it is very important to ascertain and assess global warming impacts as risks. This is related to Article 2 of the Framework Convention on Climate Change, which states, "The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system." This article points out the importance of analyzing the threshold at which there is a danger level of warming and impacts, and shows the need to clear up uncertainty and to perceive impacts as risks.
While it is essential that governments abide by the Kyoto Protocol's numerical targets, due to the great inertia on the limiting of atmospheric CO2 emissions, it is thought that for the time being it will be impossible to arrest the global rise in temperature. Therefore, we need very much to provide answers for how to make ecosystems adapt, and what technologies there are for mitigating negative impacts at levels of stress caused by a certain degree of global warming.
Greenhouses Gases in Agricultural Ecosystems:Assessing Emission Rates and Developing Mitigation Technologies Kazuyuki Yagi 
Kazuyuki Yagi
Senior Researcher,
National Institute for Agro- Environmental Sciences (NIAES),
Carbon andNutrientCyclesDivision

1. Introduction

Agriculture is a necessary occupation of humanity which makes the maximum use of an ecosystem's energy and material balances. Whether it is primitive swidden agriculture or mechanized intensive agriculture that applies chemical fertilizers and pesticides, agriculture modifies the various cycles in ecosystems and transitions the energy and material equilibrium that has been maintained for a long time to another balanced state. While this made possible the provision of materials such as food and fiber that are civilization's foundation, it has also caused problems that modern humanity now faces, such as the chemical burden on the environment and changes in the hydrological cycle and energy balance.
One such problem that has been found is the emissions of greenhouse gases from agricultural ecosystems, which is noted to be a cause of current global warming. According to the IPCC Fourth Assessment Report (AR4) 1), which was released last year, the amount of greenhouse gases generated by the world's agricultural ecosystems is 5.1-6.1 Gt CO2 eq (carbon dioxide equivalent), accounting for 13.5% of anthropogenic emissions. The emissions and absorption of CO2, the greatest of these greenhouse gas emissions, are thought to be in balance globally. But because the greenhouse gas emissions from forests, which are calculated separately, include emissions caused by changing land use to farmland, one could say that the impacts of agriculture extend also to the forestry sector. Additionally, agricultural ecosystems account for over half the anthropogenic emissions of two other greenhouse gases, methane (CH4) and nitrous oxide (N2O), and therefore are major sources.

2. Greenhouse Gas Emissions and Mitigation Technologies

CO2Emissions from Farmland
Whether farmland is a carbon sink or source is determined by the balance between the absorption of atmospheric carbon dioxide by crop photosynthesis on the one hand and emissions by crop respiration and the decomposition of soil organic matter and crop residues on the other. Tilling farmland accelerates the decomposition of organic matter in the soil, and carbon is often taken out of the system as the harvest. Thus, soil organic matter, which had accumulated in a state of equilibrium when the land was forest or grassland, declines when the land is tilled, and tends to be emitted as carbon dioxide. However, inputs of organic matter such as compost and livestock waste slow that decline, and the accumulation as soil organic matter increases. In other words, sometimes there is a carbon storage effect.
In addition to the application of organic matter such as compost and livestock waste, other agricultural technologies that are effective ways of storing carbon are no-till and reduced tillage, crop rotation, and cover cropping. Worldwide, it is also important to curb the conversion of forests and wetlands to farmland. According to IPCC AR4 1), there are considerable expectations for the ability of farmland soil to store carbon. It is estimated that there is a mitigation potential of 3870 Mt CO2 eq by 2030 at carbon prices of up to 100 US$ per t CO2-eq, which corresponds to about 8% of the anthropogenic greenhouse gases emitted in 2004.

CH4from Rice Fields2)
Flooding of rice fields by irrigation creates an anaerobic environment in which the activity of a group of obligate anaerobic archaebacteria called methanogens synthesizes methane as an end product of organic matter decomposition. This is released into the atmosphere. Global annual methane emissions from rice fields are estimated to be 20-100 Tg, accounting for 5%-30% of anthropogenic emissions. On-site measurements of rice field methane emissions have been carried out since the 1980s, and currently results from over 100 locations, primarily in Asia, have been released. The results have been compiled, and the 2006 IPCC Guidelines3)call for a baseline emission factor (130 mg m-2day-1), and a scaling factors for increased emissions due to water mangement and organic soil amendments. In the early 1990s, a nationwide study performed on Japan's rice fields estimated annual methane emissions to be 330,000 t.
Suggested techniques to reduce rice field methane emissions include water management by using midsummer drainage and intermittent irrigation, organic matter management by which rice straw is composted and decomposition is encouraged when rice fields are not flooded, use of fertilizer or agricultural supplies, and soil amendments. Many of these are proved to be effective. Under a program of the Ministry of Agriculture, Forestry and Fisheries starting in 2008, the ministry is planning the nationwide demonstration and promotion of techniques to reduce methane emissions by means of water management for the purpose of helping Japan meet its greenhouse gas emission reductions for the First Commitment Period under the Kyoto Protocol.

N2O Emissions from Fertilizer Nitrogen4)
The nitrogen needed for crop production that is applied to farmland as chemical fertilizers or organic material changes form in the soil due to the action of microorganisms, so that NH4-N becomes NO3-N (nitrification) and NO3-N becomes N2(denitrification). N2O is formed as a byproduct in the soil in the processes of nitrification and denitrification, and is released into the atmosphere. The amount of N2O emitted from farmland generally increases with the amount of nitrogen applied, and an emission factor, which is the proportion of N2O-N formed per amount of nitrogen applied, is used to estimate the amount of N2O emitted. The 2006 IPCC Guidelines3)suggest 1.0% as the standard emission factor (default value). However, data from observations in Japan in many cases have an emission factor that is lower, while in a few cases such as tea field soil, extremely high emissions have been observed. Based on these research results, annual N2O-N emissions from Japan's agricultural land are estimated to be 4420 t N eq. The N2O emission processes are observed to be direct emission into the atmosphere from farmland, as well as indirect emissions in which nitrogen applied in farming areas runs off into groundwater and rivers, after which N2O is released by degassing.
As N2O emissions from farmland soil have much in common with another environmental problem, that of nitrate nitrogen leaching into groundwater, it is effective to develop mitigation techniques which emphasize, for example, making crops use nitrogen more efficiently, and suppressing nitrification and denitrification. Some conceivable techniques for this are improvements in fertilizer application methods, such as application of optimum amounts of nitrogen, and split or localized application; using new types of fertilizer such as slow-release fertilizer, nitrification inhibitors, and urease inhibitors; and the appropriate application of organic matter. It requires effort to use these techniques and to offer and widely disseminate nitrogen application systems appropriate to each geographical region to maintain high yields without exceeding the soil's environmental capacity; however, it is necessary in order to harmonize food production and environmental conservation.

CH4and N2O Emissions from the Livestock Industry5)
Methane from ruminant livestock, and methane and N2O from livestock waste are major sources of agricultural greenhouse gases. Global annual methane emissions from ruminants are estimated to be 80-90 Tg, which corresponds to about 25% of anthropogenic emissions and is believed to be the largest source of methane emissions. Meanwhile, although there is great uncertainty in the estimated emissions from livestock wastes, they are without a doubt a major source. Like rice fields and fertilized soil, these two sources arise from the activity of microorganisms, and generate methane and N2O by the same mechanisms.
In the first stomach (rumen) of cattle, goats, sheep, and other ruminants, methane is constantly generated from feed carbohydrates, and its amount usually corresponds to 2%-12% of ingested energy. Because emitting methane represents an energy loss for livestock, research into mitigating emissions is also being carried out from the pint of view of using feed more efficiently. But because methane synthesis also functions to eliminate metabolic hydrogen, which is harmful to the proliferation of microorganisms in the rumen, appropriate control is needed. With this in mind, one recognized effective way of both improving livestock productivity and diminishing methane emissions is administering preparations (such as copper sulfate, ionophores, antibiotics, and unsaturated fatty acids) that control the activities of protozoa and microorganisms in the rumen. It is also effective to reduce high-fiber feed (roughage) and increase the proportion of concentrates, which have high nutritive value. As a more practical applicable technique, developing countries have confirmed the effectiveness of adding food manufacturing byproducts such as rice bran and brewer's grain.
There is a variety of conceivable ways to hold down emissions from livestock waste; these involve feed, waste disposal (composting), applying waste to farmland, and the like. But for composting and application to farmland such measures are complicated because of the frequent tradeoff arising with methane generated under reductive conditions, and N2O generated due to more oxic conditions. Recently it has been observed that adding essential amino acids could improve the efficiency of feed use and reduce the amount of livestock waste generated per head or per unit product, raising expectations for this as a way to mitigate greenhouse gas emissions.

3. Possibilities for Reducing Greenhouse Gas Emissions from Agricultural Ecosystems

As seen above, various sources in agricultural ecosystems emit the three major greenhouse gases CO2, CH4, and N2O. Quantitative assessments of local and global emissions contain uncertainties owing to the diversity of agricultural ecosystems, and although there is room to reduce those uncertainties, it is clear that there is significant global warming impact. Many techniques have been proposed to mitigate emissions from farmland and livestock, and on-site tests and other procedures have confirmed the considerable reductions achieved by many of these techniques, such as water management (in rice fields), organic matter management, and fertilizer management for farmland, and feeding and waste disposal management for livestock. However, at this time there are very few instances in which these techniques have been implemented in actual farming operations to reduce greenhouse gas emissions. Under the Kyoto Protocol, only Canada and three other countries have chosen farmland as carbon sinks. And although some countries are planning CH4and N2O reductions, it seems there are still no cases of actual implementation.
One reason that techniques for reducing greenhouse gas emissions from agricultural ecosystems have yet to be put into practice is the insufficient assessment of the economic benefit conferred by cutting emissions. Taking into account cost and labor, since many farming operations are family-run, there is hardly any possibility for wide adoption of a technique unless it improves overall earnings and makes work easier. This makes it necessary to conduct detailed assessments of each technique's economic effect in various regions, and to show the possibility of it being accepted by farmers. Also needed is policy support to promote such techniques.
Additionally, although emission-mitigating techniques have been assessed for farmland and livestock themselves, further efforts will be needed to counter the insufficiency of assessments covering whole agricultural ecosystems and entire geographical regions. Dealing with this problem will require the introduction of lifecycle assessment (LCA) of the new techniques that look at the balances of whole systems and include such factors as additional inputs of energy and agricultural supplies or the production and use of feed. Take for example livestock wastes, which have the potential to release greenhouse gases at various times during their handling. It is necessary to comprehensively assess area-wide collaboration between livestock farmers and crop farmers and find the solution which best satisfies both productivity and farming economy, while at the same time having the smallest greenhouse gas emissions and not increasing other environmental burdens. For biofuels, whose production is growing in recent years, researchers should also assess their effectiveness in reducing fossil fuel use, and the possibility that their cultivation will increase greenhouse gas emissions.
Another issue is that the proportion of greenhouse gas emissions from the agriculture sector in developed countries is relatively low, putting most of the reduction potential in developing countries. In Japan, agriculture accounts for a mere 2% of the greenhouse gas emissions inventory, while in tropical Asia, whose agricultural system is also based on wet rice cultivation as in Japan, agriculture accounts for a very high proportion of emissions, such as 28% in India and 35% in Thailand. Especially in countries with vast areas of farmland and many domestic animals, measures to reduce emissions by implementing agricultural techniques could make a large contribution. It is predicted that in such countries, attuning the implementation of these techniques with sustainable development policies would further advance the possibilities for reductions. It is possible that the clean development mechanism (CDM) provided for by the Kyoto Protocol could be used as a new development assistance tool.
IPCC AR41)shows clearly that, in terms of cost, greenhouse gas emission reduction measures in the agricultural sector can compete with those in the energy, transport, forestry, and other non-agricultural sectors. An advantage cited is that one can expect long-term effectiveness, and that overall a major contribution could be made. Developing new techniques in the agricultural sector is not only a promising way to reduce greenhouse gas emissions, but also coincides with the orientation toward sustainable or environmental friendly agriculture, which is the desirable future form of agriculture. Certainly now when we are pressed to act on global warming, we perhaps have a good opportunity to press forward with international negotiations to make appropriate land use possible, and to blueprint the desirable form of future agriculture that is in harmony with nature.

Citations

  1. IPCC (2007): IPCC Fourth Assessment Report (AR4): Climate Change 2007, Cambridge University Press. http://www.ipcc.ch/
  2. Yagi, Kazuyuki (2004). Atmospheric Methane Dynamics and Methane Emissions from Rice Fields. "Agro-Environmental Research Series, No. 15, Carbon and Nitrogen Cycles in Agricultural Ecosystems," pp. 23-50, National Institute for Agro-Environmental Sciences.
  3. IPCC (2006): IPCC Guidelines for National Greenhouse Gas Inventories.
  4. Yagi, Kazuyuki (2006). "Greenhouse Gas Emissions and Their Assessment." Fertilizer Encyclopedia, pp. 358-365, Asakura Shoten.
  5. Japan Livestock Technology Association (2002). Controlling Livestock Greenhouse Gas Emissions (Compendium).
Health Impacts, Mainly Infectious Diseases, Due to Climate Change Hitoshi Oshitan
Hitosh Oshitani
Professor, Tohoku University
Graduate School of Medicine

In 2003, international organizations (WHO, WMO, and UNEP) issued a report on the health impacts that might occur in conjunction with climate change, titled Climate Change and Human Health-Risks and Responses; in 2005, WHO also issued Using Climate to Predict Infectious Disease Epidemicsabout the impacts that climate change might have on infectious diseases. As stated in those documents, it is difficult to accurately predict the impacts of climate change on health. Infectious diseases and other health damage occur because of complexly interrelated factors including sanitary conditions, state of nutrition, host immunity, pathogenicity of pathogens, and routes of transmission. Therefore normally it is hard to predict how climate change that is only one of the parameters impacts will be manifested.
Climate Change and Human Health-Risks and Responsessummarizes the health impacts of climate change as shown in the diagram below.

no41_gazo01.jpg

Conceivable first of all are direct health impacts that occur as a direct result of climate change, such as the harm caused by heat waves and extreme weather events. Next is indirect harm such as changes in the patterns of infectious disease epidemics caused by, for example, environmental changes due to changes in temperature and precipitation and changes in transmission routes. A third possibility is health damage that occurs in a more indirect manner, such as impacts on agriculture and depletion of water resources owing to changes in temperature and precipitation, and impacts on the socioeconomic system. Regarding the health impacts of climate change, direct harm such as heat waves and increased infectious diseases are often addressed, but it is possible that the third mechanism will have the largest impacts over the long term.
 There are also a number of conceivable mechanisms by which climate change affects infectious diseases. Some of these are: (1) The occurrence of infectious diseases due to extreme weather events, (2) increase in infectious diseases from water and food because of water and food shortages, (3) increase in infectious diseases whose vectors are animals or insects, in conjunction with increases or changes in the distributions of vectors, such as mosquitoes, that transmit infectious diseases, (4) increase in infectious diseases owing to ocean changes such as rises in sea level and in seawater temperature, (5) changes in the seasonality of infectious diseases that are seasonal, such as influenza.
 Many infectious diseases are given as those which might possibly be affected by climate change, but only a limited number of these have been linked on scientific grounds to climate change. One of these diseases is dengue fever, for which it is thought that the expanded habitat of the vector mosquito due to global warming might lead to a larger geographical range for the disease. Cholera is always present in brackish waters, and it has been proved that cholera is more active when seawater becomes warmer. It is known that larger populations of the mosquito vector for Rift Valley fever, a serious infectious disease found in Africa, directly increase the number of human victims. Influenza and other seasonal infectious diseases might be considerably affected by climate change, but it is unknown what kind of impact there will actually be. It is also hard to predict accurately how many other infectious diseases will be affected by climate change.

no41_gazo02.jpg

Figure 2. Impact of climate change on infectious diseases
  1. Climate change
  2. Extreme weather events
  3. Changes in amounts and patterns of precipitation
  4. Higher temperatures
  5. Insufficient safe water and food
  6. More animal and insect vectors for infectious diseases
  7. Sea level rise and other environmental changes
  8. Outbreaks of infectious diseases because of typhoons and other natural disasters
  9. More infectious diseases whose vectors are water and food
    Examples: Diarrhea, food poisoning
  10. More infectious diseases whose vectors are animals and insects
    Examples: Malaria, dengue
  11. More infectious diseases because of environmental changes
    Example: Cholera
  12. Changes in patterns of seasonal infectious diseases
    Example: Influenza
The IPCC Now:-Walking the Fine Line between Neutrality and Policy Prescriptiveness-  Anne McDonald
Anne McDonald
Associate Professor,
The International Center of MiyagiUniversity

Twenty years have passed since the establishment of the Inter-governmental Panel for Climate Change (IPCC). Set up by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP), the IPCC was formed as a policy neutral scientific body with a mandate to provide decision-makers with scientific technical and socio-economic information about climate change.1
This paper is not concerned with an analysis of the actual findings of the IPCC reports, but rather will look at how the role(s) of the IPCC have evolved, specifically IPCC's role as a major source of information for global climate change related negotiations and as a voice in influencing climate change related policies both globally and regionally.
Of central interest is the role of IPCC's most recent report, the 4th Assessment Report, in Post-Kyoto negotiations. With increased scientific certainty of climate science, it may be argued that the voice of IPCC has incrementally strengthened; the co-awarding of the 2007 Nobel Peace Prize to IPCC attests to this.
Along with this elevated recognition and status, however, comes the question of whether the IPCC has been able maintain its policy neutrality or has it crossed the line over to being a policy prescriptive negotiating force.
While investigating the fine line between scientific neutrality and policy prescriptive inclinations, this paper will attempt to identify the potential roles for IPCC's forthcoming 5th Assessment Report, including roles to be played by Japan within the IPCC.

1 IPCC mandate is "to assess scientific, technical and socio-economic research relevant to understanding the risk of human-induced climate change, its observed and projected impacts, adaptation and mitigation options available to policy makers".
Climate Change Impacts, Adaptation, and Mitigation Measures:Findings of the Synthesis Report Hideo Harasawa
Hideo Harasawa
Director,
Social and Environmental System Division,
NationalInstitute for Environmental Studies

1. Introduction

2007 was an important year for considering how to deal with global warming. The IPCC Fourth Assessment Report's Working Group I Report (The Physical Science Basis), released on February 2, 2007, showed scientifically that global warming is evident from the global temperature upswing and other observations, and that it is quite likely the cause is carbon dioxide and other greenhouse gases emitted by human activities. The Working Group III Report (Mitigation of Climate Change) released in April showed that holding the extent of global warming down to about 2°C requires greenhouse gas emissions to peak in the next 10-20 years, and a cut of at least 50% in 2050, and that cutting emissions is possible by mobilizing current reduction technologies and by using economic incentives such as pricing carbon.
In November, at the 27th Session of the IPCC (November 12-17, 2007, Valencia, Spain), the Synthesis Report summarizing the three working group reports was adopted. UN Secretary-General Ban Ki-moon also attended, a press conference was held, and the report was released worldwide. This report was used at COP13, which was held on Bali, as basic material for discussion on the framework for 2013 and beyond. In Japan, the government announced the Strategy for an Environmental Nation in the 21st Century, under which Japan will halve its greenhouse gas emissions in 2050, and also announced Blue Planet 50, showing the world Japan's basic approach for its long-term strategy to combat global warming.
On October 12, before the IPCC session, the decision was made to jointly award the IPCC and former US Vice President Al Gore the Nobel Peace Prize. The reason given was that they had accumulated and disseminated scientific knowledge on anthropogenic climate change and laid the foundation for addressing climate change. Global warming has now developed into a problem so serious as to jeopardize world peace. All countries, both developed and developing, must draw on the IPCC's global warming prescription. While keeping an eye fixed on the long-term future, they must in the short term attain their reduction commitments for the Kyoto Protocol's First Commitment Period, and then they must develop plans for the more rigorous emission reductions to come, and build truly low-carbon societies.
Below I describe the IPCC Fourth Assessment Report (especially the Synthesis Report), which is especially important as the scientific basis for considering how to deal with global warming.

2. IPCC Fourth Assessment Report and the Synthesis Report

The Fourth Assessment Report comprises reports by the three working groups and a comprehensive Synthesis Report prepared on the basis of those three reports. Based on the scientific knowledge gained after the Third Assessment Report (2001) was released, the Synthesis Report summarizes in a crosscutting and comprehensive manner the scientific knowledge brought together in the working group reports. This knowledge includes the phenomenon of climate change, its causes, predictions, impacts, adaptation, and mitigation. The Synthesis Report consists of the full text and the Summary for Policymakers (SPM). The Synthesis Report's SPM was prepared to provide the world's people and especially policymakers and politicians with the latest scientific knowledge in a brief form. The Synthesis Report is based on the full text and SPM of each working group report; it uses many tables and graphs, and is easy to read and understand.
The Synthesis Report encompasses the following six topics.

  1. Observed changes in climate and their effects
  2. Causes of change
  3. Projected climate change and its impacts
  4. Adaptation and mitigation options
  5. The long-term perspective
  6. Robust findings, key uncertainties

The sixth is contained only in the full text. The full text and SPM are available in the originals and Japanese translation (IPCC [2007], Ministry of Education, Culture, Sports, Science and Technology [2007]).

Topic 1. Observed changes in climate and their effects
 This section presents the observed climate changes and their impacts on humanity and natural systems.
  • Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.
  • Many natural systems are being affected by regional climate changes.

Topic 2. Causes of change
Presents the observed causes of change.
  • Global GHG concentrations are much higher than the level of pre-industrial times due to human activities.
  • Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the increase in anthropogenic GHG concentrations.

Topic 3. Projected climate change and its impacts
Presents short- and long-term climate change and its impacts based on various suppositions about the future (emission scenarios). 
  • It is projected that if current policies are continued, global GHG emissions will continue to grow over the next few decades, and global warming in the 21st century will exceed that observed in the 20th century.
  • It is predicted that many changes will be brought about in Earth's climate system. Predictions include impacts by sector and when they appear, impacts anticipated for certain regions, and extreme phenomena (such as extreme weather events).

Topic 4. Adaptation and mitigation options
Arresting global warming requires reducing emissions of greenhouse gases, which are the cause. Ways to reduce greenhouse gas emissions are called mitigation. The impacts of global warming are already evident around the world, and it is predicted that if warming continues, its impacts will appear in various sectors, and in both the developed and developing countries. This topic discusses adaptation and mitigation, and describes the relationship with sustainable development on global and regional levels.

・Reducing vulnerability to climate change necessitates stronger adaptation strategies than at present. The report gives examples of specific adaptive measures for different sectors.
・Implementing appropriate mitigation measures could offset and reduce the increase in global greenhouse gas emissions over the next several decades.
・In the report's estimation, the UN Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol have built the foundation for future efforts at mitigation as an international framework for encouraging mitigation

Topic 5. The long-term perspective
As a long-term perspective, and especially in accordance with the ultimate goals and provisions of the UNFCCC, this section presents the scientific and socioeconomic aspects of adaptation and mitigation in connection with sustainable development.

・The following five "reasons for concern" in relation to climate change, which the Third Assessment Report identified, are even stronger.
1.Increased risks to unique and threatened systems, such as polar and high-mountain communities and ecosystems.
2.Increased risks of extreme weather events such as droughts, heat waves, and floods.
3.Major impacts and vulnerabilities affect those who are regionally and socially in weak positions.
4.The benefits of global warming will peak at lower temperatures. As warming proceeds, the damage will worsen, and the costs of global warming will increase with time.
5.There will be increased risks of major change, such as accelerated sea level rise and ice sheet loss.
・It is possible that neither adaptation nor mitigation measures alone will be enough, but they can complement each other and together can considerably lower the risks of climate change.
・Stabilization of greenhouse gas concentrations is possible with existing technologies and those that will become available in coming decades. The key is the mitigation effort and investment made in the next 20-30 years.

Topic 6 appears only in the full text. It is a discussion on robust scientific findings and uncertainties. This topic was deleted from the SPM.

3. The Significance of the Fourth Assessment Report (Center for Global Environmental Research, 2007)

Preparation of the Fourth Assessment Report concluded with the release of the Synthesis Report; however, future IPCC sessions are planned to evaluate the Fourth Assessment Report and IPCC activities. The significance of the Fourth Assessment Report will probably be discussed, but the significance at this point in time can be summed up as follows.

(1)Warming of the climate system is unequivocal.
 Climate change observations and elucidation of phenomena have made progress. Warming of the climate system is assessed as very likely, and it is nearly conclusive that the causes of global warming are greenhouse gas emissions and other human activities. For such reasons the certainty of scientific knowledge on climate change improved substantially.

(2) The impacts of global warming are now apparent.
 On all continents and in almost all oceans, it is now clear that the natural environment, such as snow, ice, and ecosystems, as well as human activities, are affected.

(3) Global warming has impacts on various sectors and regions.
 It is predicted that at the end of the 21st century the average global temperature will be 1.1-5.8°C higher, and sea level will be 18-59 cm higher, than in the 1990s, with impacts appearing in various sectors and regions. A rise of 2-3°C in temperature over that of the 1980s and 1990s would temporarily bring favorable effects (for example, warming in cold regions would make grain cultivation possible), but harmful impacts would prevail with greater temperature increases.

(4) Climate change must be addressed quickly.
 To arrest global warming, it is necessary to achieve a downward curve in greenhouse gas emissions during the next 20 to 30 years so that emissions are substantially reduced in 2050. The report identified the relationships between long-term stabilized concentrations and remedial measures, which will aid consideration of the post-Kyoto framework.

(5) Mitigation is cheaper than the damage
 In the way of mitigation measures, greenhouse gas emissions can be sufficiently reduced with current technologies, economic measures, and changes in lifestyle and consumption patterns. And if one takes the cobenefits into consideration, the economic costs are lower than the cost of global warming damage.

(6) Both mitigation and adaptation are necessary
 Mitigation to prevent global warming and adaptation to alleviate the impacts of global warming are both needed. Combining them well makes it possible to reduce the risks of global warming with limited funds. But there are still various constraints on implementing both.

4. Future Developments and Japan's Contribution

The Fourth Assessment Report has been completed, but already activities for the Fifth Assessment Report have begun. The fifth report is expected to be released around 2013, and because the writing will take about three years, various activities will probably start this year. It is important to pursue work in the following areas for Japan's contribution to the fifth report in terms of research.
・Release of peer reviewed English-language papers: Because the IPCC uses peer reviewed papers as an information source, it is important as always to release papers. Japanese-language reviewed papers are also used for the assessment if they have English-language abstracts. It is also effective to send papers to the IPCC and to the report's writers and other well-known researchers.
・Participation as writers: Now that the Fourth Assessment Report is finished, over the next one or two years there will be scoping meetings and other meetings to set up next system (election of chairperson and bureau). These meetings will discuss the issues to be addressed by the next report and decide the draft table of contents. After this, the writers are chosen. Thirty Japanese researchers contributed to the Fourth Assessment Report, and we hope that even more will contribute as writers to the fifth report. 
・Review of Japan's global warming research: It would also be effective to conduct a review of papers on global warming to summarize the achievements and findings of Japanese research and publish the review as an English-language report or book.
・Active participation in IPCC workshops and other meetings: From now on the IPCC is expected to hold frequent workshops on various issues. It is important to actively participate in such workshops and present Japanese research.
・Support for global warming research in Asian developing countries: APN(Asia-Pacific Network for Global Change Research) and other organizations lend support (such as support for research on impacts in developing countries), but currently there is too little support by Japanese researchers, which makes pursuing research extremely difficult. It is important for Japan to provide cooperation and support for global warming research conducted by Asia-Pacific countries.

References

1)Center for Global Environmental Research (2007).
Highlights of the IPCC Fourth Assessment Report, 12 pp.
2)Ministry of Education, Culture, Sports, Science and Technology; Ministry of Economy, Trade and Industry, Meteorology Agency; Ministry of the Environment (2007).
On the Release of the ss kit.
3)IPCC (2007) Summary for Policymakers of the Synthesis Report of the IPCC Fourth Assessment Report. 23 pp.
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発行日 2008年8月1日