Assessing the environmental and climate crisis in the Japanese context: Shigeto Tsuru revisited

Abstract

This paper examines the political economy of the environment in the era of climate crises. The guiding thread is Japanese political economy of the environment pioneer Shigeto Tsuru’s methodology. Specifically, the guiding threads are “the distinction and unification of the real-physical and value-institutional aspects” and “the socialization of flow.” The paper will consider contemporary features of environmental problems and the climate crisis in conjunction with examining the development of Japan’s political economy of the environment. Tsuru’s theory to Kenichi Miyamoto’s intermediate system theory and environmental damage theory will be explored alongside Japan’s decarbonization policy and problems of “carbon captive structure of political economy.”

Keywords:

• Carbon captive structure of political economy
• climate crisis
• Japan’s decarbonization policy
• Shigeto Tsuru’s methodology

Introduction

This paper considers Japan’s development of the political economy of the environment by examining academic pioneer Shigeto Tsuru’s methodology. In doing so, we will also refer to modern capitalism’s problems and institutional challenges regarding the contemporary climate crisis. Tsuru’s political economy of the environment was systematized before the climate crisis became severe. However, it is still effective in analyzing today’s climate crisis.

Tsuru (1999) summarized his political economy of the environment while his academic life and theoretical characteristics were later introduced by Suzumura (2006). However, despite these, the significance of Tsuru’s political economy of the environment, the development of subsequent discussions, and its organization with regards to the contemporary global and Japanese economic situation have not been fully developed. Also, in non-neoclassical environmental economics there is almost no mention of Tsuru and Japan’s political economy of the environment (e.g., Daly and Farley 2010). Therefore, it is difficult to presume that the political economy of the environment in Japan has been sufficiently introduced globally.

Tsuru and his followers should reaffirm the scope of the political economy of the environment in Japan on an international scale. As such, the contribution of this paper is also in this regard and it begins with explaining the relationship between the climate crisis and modern capitalism.

Climate crisis in modern capitalism

Climate change problems as global pollution

Climate change is a global pollution problem in which human economic activities have resulted in greenhouse gas (GHG) emissions that are destroying the climate system. Regarding this, mitigations are “ex-ante policies” intended to stabilize GHG concentrations in the atmosphere before climate change becomes a severe problem. Whereas, adaptations are “ex-post policies” that take the progression of climate change as a given and implement measures to mitigate its negative effects. In recent decades, natural disasters have been occurring more frequently in Japan, and the increase and worsening of natural disasters, food problems, and health problems are risks brought about by climate change. It is becoming increasingly important to respond to these risks by investing in disaster mitigation and prevention, public health and medical measures, environmental refugee measures, and other adaptation measures.

Challenges of the Paris Agreement

The Paris Agreement adopted at COP21 in 2015 sets a goal of limiting global warming to well below 2 °C with pursuing efforts limiting it to below 1.5 °C. According to the Intergovernmental Panel on Climate Change (IPCC), to keep the temperature and its increase below 1.5 °C, CO₂ emissions must be reduced by about 45% from the 2010 level by 2030 and virtually zero by around 2050. Therefore, the Paris Agreement calls for achieving carbon neutrality (a state where the amount of GHG emissions equals the amount absorbed by forests, etc.). In contrast, the Kyoto Protocol did not set such an environmental goal. Additionally, the effectiveness of the Protocol was questionable because the United States (US) withdrew from it as the country did not want to be obligated to reduce emissions while large emitting developing countries such as China and India were not bound to reduce theirs. Therefore, a major challenge was securing more countries’ participation, especially significant emitters.

The Paris Agreement adopts a mechanism whereby all countries present their “Nationally Determined Contributions” and act toward those targets rather than a reduction obligation assigned to each country. Each country must submit and update its reduction target every five years while verifying those targets and progress every five years. The verification process is called the “Global Stocktake,” and the first round was implemented in November 2021. Other issues on the agenda include the enhancement of adaptation policies, the expansion of support schemes for developing countries, and the use of international market mechanisms. Although the Paris Agreement is an ambitious and essential instrument, it still has challenges as a global cooperation framework, such as the failure to achieve the $100 billion annual aid target for developing countries by 2020.

The IPCC’s Sixth Assessment Report, the Working Group I Report, which addresses the physical science basis of climate change, was released in August 2021.¹ It clearly states that human activities are causing the warming of the atmosphere, oceans, and land, and that the changes in the climate system in recent years are on a scale never seen in the past few hundred or thousand years. Without significant reductions in GHG emissions, the range of global temperature increases since the Industrial Revolution period will exceed 1.5 °C or 2 °C by the end of this century. The larger the temperature increase, the more serious the risks associated with climate change, such as extreme weather events and ecological and agricultural damages. Furthermore, there are increasing warnings that many irreversible changes will befall Earth’s ecosystems. To cope with these worsening climate crises, the Paris Agreement alone is not enough, but requires constant updating alongside each country’s efforts.

Climate change and modern capitalism

Modern capitalism is in an era in which “Disposal Constraints” on the natural environment have become apparent. Disposal constraints refer to the technological and social difficulties in production, consumption, and living in the community that make it difficult to dispose of material.² We are entering a stage where we are forced to face disposal constraints and design our economy based on these constraints. From this perspective, the most serious and global problem is climate change; in terms of disposal constraints, the problems are associated with the intensification of the greenhouse effect and the resulting changes in the climate due to a large amount of GHG being disposed of in the atmosphere. Significant reductions in GHG emissions are needed to meet the disposal constraints required by global environmental capacity. The international framework for the prevention of global warming is still being discussed at the Conference of the Parties to the United Nations Framework Convention on Climate Change, which can also be considered a negotiation over allocating GHG emission rights under disposal constraint (Ueta 2013, 101–102).

Climate change problems also threaten to overturn the assumptions of the energy system as social capital. The premise is that the continued use of fossil fuel-based energy is likely to become unsustainable, not because fossil fuels will be depleted and no longer mined, but because fossil fuels that emit GHG can no longer be burned.

Let us review Herman Daly’s (1990) three principles of sustainability. (1) The rate of sustainable use of renewable resources must not exceed the rate of their regeneration; (2) the sustainable use of nonrenewable resources should be, at most, the rate at which they can be substituted using renewable resources at a sustainable rate; and (3) the sustainable rate of emissions of pollutants must not exceed the ability of the environment to circulate, absorb, and detoxify such substances. If the energy system is designed according to the sustainability principles, then in the long term, renewable energy must become the core energy system. In the short to medium term, one of the criteria for judging the adequacy of energy policies will be whether or not an energy system is moving in a direction that better meets the sustainability principles. Daly’s sustainability principles are a discipline that binds human society’s energy resource use behavior from the perspective of the nature-human relationship (Ueta 2013, 89).³

Political economy of the environment in Japan

Shigeto Tsuru’s methodology

A central concept in Tsuru’s (1912–2006) political economy of pollution and environmental problems is the analytical approach of distinguishing and unifying the real-physical and value-institutional aspects.⁴

The “real-physical aspect” here is a transhistorical one that can be objectively described independently of the regime. Conversely, the “value-institutional aspect” is a historical concept that includes the market, state, and economic system, which are social mechanisms that change with history. Although the environment is inseparable from the material aspects, it is systemically fragmented and improperly managed. Tsuru believes that this duality of material and systemic aspects gives rise to environmental problems.

Citing milk consumption, Tsuru explains it as follows. First, from a material standpoint, milk consumption has five stages: (1) milk production, (2) container production, (3) distribution process, (4) consumer purchase, and (5) container processing, and their interconnectedness is inseparable. Therefore, there is potential to manage all five stages unified. In a capitalist society, however, each stage is carried out by a different economic entity and is divided into further stages. This is the effect of the systemic aspect, or political and economic system, such as establishing private property rights and the rule of decentralized decision-making by separating producers and consumers. This leads to the principle of profit maximization by corporations in (1, 2), and (3), and the principle of satisfaction maximization in the household in (4). If disposable containers are generally adopted, a waste disposal problem will arise in (5). In the container processing, consumers will sort and discharge waste, but local governments will collect and dispose of it as no consideration will be given to this issue.

More generally, the activities of a market economy internalize the interconnected real aspect by the demands of value in exchange (the value-institutional aspect). In contrast, the market releases what is no longer needed internally to the outside world. The value in use (the real-physical aspect) is a resource whose intrinsic value is not fully evaluated. It is not priced according to the “internal” logic of institutional aspects and is often not subject to exclusive property rights. While the market economy tries to incorporate mass production and science and technology into its internal, it fractures the unity of the real-physical aspect. It ignores as much as possible the negative effects on the external.

Tsuru emphasizes the relationship between the market economy and environment in this way and argues that policy considerations that give an advantage to the real aspect are necessary. This differs from Pigouvian policy prescriptions that attempt to internalize the natural environment into the market by evaluating it as market prices. Rather, it is an argument that maintaining certain qualitative levels of the natural environment should be prioritized to value in exchange. For example, the 1.5 °C target in the IPCC is precisely the policy that gives priority to the qualitative level of the natural environment over value in exchange. To prioritize the use in value situation of the climate level, institutional mechanisms on the exchange in value side (pricing in the market and subsidy schemes by the public sector) become important. In this sense, Tsuru’s methodology of distinguishing and integrating the material and institutional aspects is perfectly appropriate in the era of the climate crisis.

Succession and development of Tsuru’s methodology

Kenichi Miyamoto (1930–) follows and develops Tsuru’s “real-physical and value-institutional aspects” approach.

Miyamoto specifically analyzes an “intermediate system,” which is a general term for the integrated economic and political–social systems that govern the occurrence of environmental problems and environmental policy responses. Mentioned explicitly as economic systems are (1) the structure of capital formation (accumulation), (2) industrial structure, (3) regional structure, (4) transportation systems, (5) lifestyle, and (6) waste and material circulation. It is understood that political and social systems control pollution and environmental problems that arise from these economic systems or, conversely, may be exacerbated.

As political and social systems, the items enumerated include (7) the manner of public intervention by the state (a. the nature of fundamental human rights, b. the state of democracy and freedom), (8) the nature of civil society, and (9) the nature of globalization.⁵

In the political economy of contemporary pollution and environmental problems, the challenge is to elucidate the background of the formation of these “intermediate systems” (i.e., determining the capitalist system, the socialist system, the stage of development of the productive forces of each country, and the historical and social character of each system) and analyze their interconnected structure. We must also note that the systems are not closed within a single country. Therefore, further analyzing globalization as an element that significantly impacts contemporary environmental problems and policies is necessary. This applies, for example, to the study of decarbonizing the world economy under the Paris Agreement.

Miyamoto’s analysis attempts to concretize and enrich the content of “institutional aspects” in Tsuru’s “real-physical and value-institutional aspects” approach by focusing on the economic system, the state, civil society, globalization, and other political and social systems and the nexus among these systems.

For the analysis of contemporary environmental problems and policies, it is important to pay attention to so-called “market failure” and “government failure” caused by bureaucracy and collusion between the public and private sectors, and “institutional failure” caused by the existence of transaction costs and other factors that prevent rules on the environment and resource use from functioning. It is critically important to focus on these “triple failures.”⁶

Environmental problems are mainly caused by capitalist production relations, in which companies cut costs on environmental protection and safety to pursue profits. Conversely, governments fail to implement policies to prevent pollution or to make adequate expenditures for environmental protection. In the postwar Japanese experience with pollution and the severe accident at the Fukushima Daiichi Nuclear Power Plant, the environmental damage caused by government failure is as great as or greater than the damage caused by market failure, and it is impossible to ignore.⁷

Environmental costs are those environmental damages that can be captured in monetary terms. A typical contemporary example of negative environmental costs is the costs associated with nuclear power plants. Costs associated with the Fukushima Daiichi nuclear accident continue to mount. According to Tokyo Electric Power Company Holdings, Inc. (TEPCO) and the government, of the 21.4 trillion yen estimated costs, 1.5 trillion yen has been spent on decommissioning, 7 trillion yen on compensation, and 4.8 trillion yen on decontamination. This means that nearly 20% of the estimated cost has been spent on decommissioning with more than 80% on compensation and decontamination. Of these costs, TEPCO will pay for the decommissioning out of its profits. Government bonds and other funds will cover compensation and decontamination costs, and the power companies, including TEPCO, will pay approximately 200 billion yen per year into the national treasury. Taxes added to electricity rates will also be used to repay the debt. There is also a plan to raise decontamination costs by selling TEPCO shares. Calculations indicate that paying off the debt will take about 30 years. However, there is no guarantee that the treatment costs will be met in the projected time frame. The decommissioning of the reactors is planned to be completed within 30 years, but the most difficult process of removing molten nuclear fuel (debris) has not yet begun. There is concern that the project will be protracted. The Japan Federation of Bar Associations also points out that the potential amount of compensation may exceed the estimated amount (7.9 trillion yen) because some disaster victims have not yet filed for compensation. As a lesson learned from the pollution, monetary expenditures will not cover such damage; it is usual for the extent of environmental damage to exceed the compensation provided. This is evident in the “absolute loss” of pollution, such as Kumamoto Minamata disease, including the unrecognized problem of pollution victims. The government is also primarily responsible for the neglect of safety costs by TEPCO and the same applies to the issue of cost-sharing for victim relief, restoration costs, and compensation for environmental damage. This all shows that pollution is not over in the 21st century.⁸

Along with this, we find that the Tsuru–Miyamoto approach to political economy, which distinguishes and integrates the material and regime aspects, is effective.

Trends in Japan’s decarbonization policy

In Japan, the “Green Growth Strategy for Carbon Neutrality in 2050” was released in December 2020. In this strategy, the path toward carbon neutrality requires the expansion of decarbonized electricity in the power sector and the decarbonization of fuel and heat use in the nonpower sectors of industries, consumers, and transportation through electrification with decarbonized electricity, hydrogen, methanation, synthetic fuels, etc. Even with this shift in power sources and fuels, CO₂ emissions will still need to be reduced to virtually zero through afforestation and direct air carbon capture and storage.

Let us consider the Japanese government’s 2050 carbon neutrality vision. The energy mix in the 2030 mix is planned to reduce CO₂ emissions from non-electric and electric power generation by 25% from the 2018 level, and the energy mix is expected to be about 56% thermal power, 20%–22% nuclear power, and 22%–24% renewable energy. However, this level of renewable energy has almost been achieved, therefore a revised Basic Energy Plan in 2019 raised renewable energy from 22%–24% to 36%–38%. This increase was introduced because the Japanese government had formulated only a very modest plan, which was at odds with the country’s reality.

The 2050 target calls for carbon neutrality in terms of emissions plus absorption. The goal is to achieve carbon neutrality through the use of carbon fixation by science and technology and forest sinks. Additionally, technologies that have not yet been commercialized, such as thermal power, Carbon Capture, Utilization, and Storage (CCUS), carbon recycling, and hydrogen and ammonia power generation as decarbonized power sources, are clearly positioned. As a result, there is a clear focus on preserving carbon emission structures and symptomatic measures by maintaining or returning to fossil fuels and nuclear power (restarting nuclear power plants and revising rules for their extension) and relying on uncertain technologies rather than promoting renewable energy, which is currently a definite decarbonizing energy source.

The Green Transformation (GX) Promotion Law is a policy that was enacted in May 2023 intended to monetarily support these problematic plans. The GX mechanism, as described by the Japanese government, is as follows. First, the government raises and disburses about 20 trillion yen in GX Economic Transition Bonds, intended to attract private investment. As a result, the government will invest in decarbonizing the automobile industry and expanding the introduction of renewable energy, ultimately realizing the 150-trillion-yen investment expected to achieve CN by 2050. For this to be realized, financing must proceed smoothly. However, some of the investment projects envisioned by the government are based on the continued use of fossil fuels. Others are related to nuclear power generation, and it is unclear whether the investments can be financed considering international standards for decarbonization financing.

Carbon pricing (CP) is envisioned as the source of funds to redeem the GX Economic Transition Bonds, and the plan is to complete the redemption by 2050. In general, CP is a policy scheme to reduce emissions through a market mechanism by estimating the cost of GHG emissions, like damages to agricultural products, and adding the cost to the market price of gasoline and other products. In other words, the policy goal is to achieve “internalization of externalities.” According to the World Bank (2023), 73 countries and regions have decided to introduce CP schemes consisting of carbon taxes and emissions trading schemes in 2022, and 23% of global GHG emissions are now covered by the CP schemes currently in operation.

Japan’s GX Promotion Law uses two methods of CP (emissions trading and charges). The former will begin in earnest in 2026 and will first adopt a system based on the basement credit method, in which companies set targets based on government guidelines. Third-party organizations are expected to check these targets. However, this system is expected to be less effective in reducing GHG emissions than the cap-and-trade system that the EU and other countries have already introduced.

The latter will be introduced as a “charges on carbon” system targeting fossil fuel importers from 2028. Many CP countries worldwide, including Europe, have introduced carbon taxes, and Japan has also introduced a global warming tax, with a tax burden of 289 yen per ton of CO₂ emissions. Although this tax revenue is higher than carbon taxes in other countries, the tax rate is much lower than in countries such as Sweden. The details of the levy system currently being contemplated, including the tax rate, have not yet been disclosed. Still, if the same low tax rate as the current global warming tax is adopted continuously, it must be considered an inadequate CP system.

The government has named this CP mechanism as “growth-oriented carbon pricing” and seems to reflect the government’s desire to achieve reimbursement for the expected growth in the industry’s size through decarbonization-related investments and its desire to dodge the business community’s reaction, which has criticized strict CP as a drain on profits. In economic terms, however, the true meaning of CP is the internalization of externalities and the consequent greening of capital. If this is not realized, it will likely become a mere burden increase. Suppose Japan’s decarbonization progresses slowly leading up to 2033 when full-fledged emissions trading is expected to begin. In that case, it will create a critical time of irreversibility for climate change and the Japanese economy as major territories such as the EU and the US begin to invest in decarbonization in earnest.⁹

Tsuru’s argument is also a reference point for how to evaluate such CP. Tsuru has argued that, as a strategy for regime transition in advanced capitalist countries, a gradual transition through the socialization of surplus products generated as economic flows rather than the socialization of stocks (public ownership of means of production) has become extremely important.¹⁰

Such “socialization of flows” is a policy vision that seeks to “socialize” the net income of capital generated during economic activity without taking the means of production away from private capital and publicly owning it. For example, taxation systems are concrete means to this end. Using these means, a portion of profits is acquired by the planning authorities and used for public purposes such as the development of civilian infrastructure and social security. Tsuru believed that the “socialization of flows” strategy required a progressive political party. Alternatively, even before relying on a progressive party, Tsuru believed that it would not be impossible for local governments to navigate toward the “socialization of flows” by voluntarily reforming the current unfair tax system which favors large corporations and wealthy individuals. Rather, he saw such grassroots efforts as a steady step toward regime change. He also pointed out that even if the “socialization of flows” through tax collection is insufficient, there could be a “Central Investment Council” to regulate or guide investment flows by private enterprises. This would be aimed at guiding investment flows away from declining industries and toward promising growth industries.

Such a policy vision centered on the “socialization of flows” has new implications for evaluating CP policies, especially environmental taxes. From Tsuru’s vision, however, it can be positioned as a policy to change the structure of capital stock and profit to a level where material problems do not arise through the “socialization of flows.” However, the “growth-oriented carbon pricing” proposed by the Japanese government has not even reached the level of Pigou-like internalization of externalities.

Japanese capitalism and decarbonization

Promoting the “greening of capital” in all sectors is necessary to transition to a decarbonizing economy. In Japan there is an urgent need for green energy-related capital, a significant source of GHG emissions. In the power generation sector, the need to shift away from large scale, centralized power generation based on fossil fuels is becoming increasingly crucial for regional energy autonomy and the establishment of new basic industries.

Generally, renewable energy is characterized by a “bidirectional” energy supply in a decentralized manner by small-scale entities rather than the traditional “unidirectional” energy supply from centralized energy sources to meet demand. While small-scale, decentralized, bidirectional renewable energy initiatives that take advantage of local characteristics have emerged in Japan, the beneficiaries of feed-in tariff to promote renewable energy are urban capital and existing power-related capital. For example, many of Japan’s mega solar power plants use land in rural areas for power generation but are operated by large Tokyo-based corporations. Woody biomass power generation is also being carried out on a large scale, mainly using palm shells imported from Southeast Asia.¹¹

Behind this is the low target for the introduction of renewable energy and various related institutional factors (restrictions on renewable energy generation capacity, refusal to purchase renewable energy, refusal to connect, etc.), which have also contributed to Japan’s high cost of generating renewable energy.

The greening of capital refers to the environmentally friendly recombination of capital itself, including private and social capital. For example, even if emissions are “greened” (decarbonized) through the introduction of CCUS and other measures, this is insufficient for a second-generation environmental policy that prioritizes the precautionary principle and the implementation of environmental considerations, and the resulting greening of capital. And the Green New Deal is a specific arena for the “greening of capital.” In the case of Japan, the image of the Basic Energy Plan, which emphasizes the use of hydrogen and ammonia and assumes the use of nuclear and coal-fired power as existing power sources, is strongly reflected in the current energy system. Under such public policies, the greening of social infrastructure, like energy systems, will proceed only inadequately and will consequently put the brakes on the greening of private capital.

Compared to countries such as Poland and some US states, decarbonization and coal-free Japan do not “directly” threaten domestic industry and employment. Nevertheless, why has Japan’s shift to renewable energy progressed slowly? This is an important question for Japanese capitalism in relation to environmental and energy policy. Yoshihiro and Yamakawa (2023) examine the hypothesis that Japan’s political and economic structure, designed to procure cheap imported fuels based on the geographic location of existing energy-related infrastructure, influences the location of wood biomass power plants. This political-economic structure is called the “Carbon Captive Structure of Political Economy” (CCSPE).

The CCSPE and its power act as direct and indirect barriers to the transition to decarbonization, and even the introduction of renewable energy itself is only “complementary” to carbon-intensive power sources. Why is Japan so slow to introduce renewable energy and is strongly attached to nuclear power? When analyzing the CCSPE, it is necessary to examine Japan’s heavy and chemical industries and their power to produce nuclear and coal-fired power plants. The clarification of this CCSPE is a political economy analysis of how (or not) Japanese capitalism (which has relied on foreign resources and energy supplies, neglected the use of domestic natural resources, and promoted industrialization and large scale power generation) will change in the face of the global trend toward decarbonization.

Japan’s GX policy is proceeding in a path-dependent manner under precisely this CCSPE while maintaining existing carbon-intensive industries and capital equipment. Led by large corporations and electric utilities, nuclear power plants are being restarted, coal-fired power generation is being maintained, and hydrogen and ammonia utilization and CCUS are being promoted based on the premise of a carbon-enhancing structure. The result is a decarbonization policy that preserves the 20th-century industrial and regional structure. The “growth-oriented CP” discussed above would also assist this structure.

It is as if GX has both a gas pedal (the energy transition) and a brake (the continued use of carbon-based new technologies). The baseline for decarbonization is to prioritize the use of technologies already commercialized and marketed rather than expecting too much from highly uncertain new technologies. Among these, the maximum use of renewable energies, especially solar, wind, and geothermal energies, should be the mainstream of decarbonization.

Conclusion

The political economy of the environment in Japan started with the analysis of pollution problems, and research on the damage theory of environmental destruction has accumulated. The full-fledged development of a political economy of the natural environment and sustainability is an issue for the future. In doing so, the real-physical aspect of the natural environment tells us that attention must be paid to the “value in use” of the natural environment.

However, we are not emphasizing that value in exchange and in use should be compared or that value in use should be given priority. Furthermore, these two values can exist in their entanglement. A policy priority is necessary. In this sense, the perspective pioneered by Tsuru has not lost its luster. And suppose we are to develop a more realistic environmental economics rather than an abstract theory. In that case, it is important to start by identifying concrete environmental damage and distinguishing and integrating the monetary and material/real terms. This will confirm the importance of natural scientific findings in solving environmental problems, and it will be essential to emphasize objective environmental indicators (air pollution concentrations, water quality, etc.) as policy goals and to combine market and planning instruments to achieve these goals. Naturally, capitalism has severe problems for environmental destruction. However, simply denouncing capitalism is not a policy theory. We would like to close this paper by quoting Tsuru, who pointed out the need for a political economy of the environment as a policy theory:

“In a capitalist society, private enterprises are limited as private capital. Demanding that private capital goes beyond its limitations is nothing less than asking for the sublation of capitalism. Capitalist society contains contradictions characteristic of it, which inevitably lead to systemic change. However, we cannot expect private capital itself to be the bearer of this change. Individual private capitals know no other way to sustain themselves than by acting by their inherent laws of motion. In other words, the original responsibility for pollution phenomena in capitalist societies often lies with capitalism itself, a fundamental point we must not lose sight of. Yet, by simply repeating that the responsibility for pollution lies with private capital, we are virtually saying that there can be no pollution control measures other than the transformation of capitalism, which is not a practical prescription for everyday practice.” (Tsuru 1968, 152–153)

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 Subsequently, the Working Group II Report, which covers the impacts, adaptation, and vulnerability related to climate change, was released in February 2022. The Working Group III Report, discussing mitigation measures for climate change, was released in April 2022. The Synthesis Report, a comprehensive overview based on the three reports, was released in March 2023.

2 See Ueta (2013).

3 See also Yamakawa (2021).

4 The description is based on Tsuru (1972). Also, For Tsuru’s methodology, see Ehara and Yamakawa (2023), section 3.

5 See Miyamoto (1989, 2007). Also, For Miyamoto’s methodology, see Ehara and Yamakawa (2023), section 4.

6 See Oshima et al. (eds.) (2021).

7 For environmental damage, see Teranishi (2007).

8 See Yamakawa (2023a).

9 See Yamakawa (2023b).

10 See Tsuru (1983).

11 See Yoshihiro and Yamakawa (2023).