1Editorial: Role of Asia towards a Decarbonized World:
Roadmap of Asian Countries
Toshihiko MASUI*, Yasuko KAMEYAMA and Kiyoshi TAKAHASHINational Institute for Environmental Studies
16-2, Onogawa, Tsukuba-shi, Ibaraki, 305-8506 Japan*E-mail: masui@nies.go.jp

Abstract
Progress is being made in efforts to minimize the impacts of climate change. After the Paris Agreement,adopted in 2015, set the goals of keeping the long-term temperature increase well below 2℃ and of pursuingefforts to limit the temperature rise to within 1.5℃ from the pre-industrial period, the Intergovernmental Panelon Climate Change (IPCC) issued a special report on the 1.5℃ goal in 2018. Since then, the world has come toshare the recognition that we should first aim for a limit of 1.5℃ instead of 2℃. To that end, the total amountof global carbon dioxide (CO2) emissions must be reduced to net zero by 2050, The term “net zero,” in thiscontext, expresses a situation where any emissions are balanced by schemes to offset an equivalent amount ofgreenhouse gases from the atmosphere, such as by planting trees or using technologies like carbon capture andstorage. Carbon neutral and decarbonization are also similar terms. Based on this newly set goal, manycountries have set net zero emissions as a long-term goal. In this special issue, members of the Asia-PacificIntegrated Model (AIM), an international project that has been ongoing for more than 20 years, will introduce
the latest net zero research results in major Asian countries. Asia as a region has had some of the largest
increases in greenhouse gas emissions in the world, and achieving net zero emissions in this region will beessential for achieving the analogous global target.
Key words: climate change, model analysis, net zero, Paris Agreement, social transition

1. BackgroundAn extensive effort is being made to minimize
adverse effect of climate change. When the United
Nations Framework Convention on Climate Change(UNFCCC) was adopted in 1992, people had begun tonurture concern over climate change risks, but insufficientscientific findings had been accumulated to determine
what levels would be dangerous. Article 2 of theUNFCCC states “(T)he ultimate objective of thisConvention and any related legal instruments that theConference of the Parties may adopt is to achieve, inaccordance with the relevant provisions of the Convention,
stabilization of greenhouse gas concentrations in theatmosphere at a level that would prevent dangerous
anthropogenic interference with the climate system. Sucha level should be achieved within a time frame sufficient
to allow ecosystems to adapt naturally to climate change,
to ensure that food production is not threatened and toenable economic development to proceed in a sustainablemanner.” It took many years, however, for the world toGlobal Environmental Research
26/2022 001−003
printed in Japan

determine the “level” specified in Article 2.
Twenty-three years later, finally, the Paris Agreement
clarified the level. It states in Article 2(a) the long-termgoal of “(H)olding the increase in the global averagetemperature to well below 2℃ above pre-industrial levels
and pursuing efforts to limit the temperature increase to1.5℃ above pre-industrial levels, recognizing that thiswould significantly reduce the risks and impacts ofclimate change”. At the time of the Paris Agreement
negotiations, 2℃ was perceived as the uppermost
ambitious target that could be agreeable to all countries,
because greenhouse gas had to be net zero globally by endof this century to reach that goal, and achieving thisemission goal was not an easy task to fulfill. However,some small island countries asserted that they could notpersevere with a goal of 2℃. The world was alreadyabout 1℃ above the pre-industrial level, and the impactsof climate change were already being observed in many
parts of the world. Insertion of the 1.5℃ target wasagreed upon during the last stages of the negotiation
process.
©2022 AIRIES2T. MASUI et al.

At the time of the Paris Agreement negotiations,however, there was little scientific knowledge as to what
needed to be done to reach the 1.5℃ goal instead of 2℃.
The IPCC was requested to work on an assessment of the1.5℃ goal, and it published a special report on this theme
in 2018 (IPCC, 2018). The report revealed a distinct
difference between the two goals, 2℃ and 1.5℃, both interms of climate change impacts and emission mitigation
efforts required to achieve these goals. According to thereport, the frequency and severity of adverse impacts ofclimate change such as extreme temperatures and weather
events would be minimized if the temperature increase
was limited to 1.5℃ instead of 2℃. With this message
from the report, more people started seeing 1.5℃ as theprimary goal. After the United Kingdom officially set anet zero goal by 2050 within its climate change law inJune 2019 (Government of United Kingdom, 2019), many
countries followed suit.
On 22 September 2020, during his speech to the UN
General Assembly, Chinese President Xi Jinping
announced that China would aim to have CO2 emissions
peak before 2030 and achieve carbon neutrality before
2060. In Japan, then Prime Minister Yoshihide Suga alsoannounced that Japan would aim for carbon neutrality by
2050. Early in 2021, the newly elected US President Joe
Biden announced the United States’ new goal of net zeroby 2050. By the autumn of 2021, more than 70 countries,
including the biggest polluters-China, the United States
and the European Union-had set net-zero targets, covering
about 76% of global emissions (United Nations Net ZeroCoalition, 2022).
The 26th Conference of the Parties to the UNFCCC(COP26) was held in Glasgow, United Kingdom, in theautumn of 2021. As the host, the United Kingdom’s
government wanted to see countries revise their emission
reduction targets for the year 2030, set long-term goals fornet zero, and confirm emission pathways towards 1.5℃.
The cover decision called “the Glasgow Climate Pact”
states that it ”(R)eaffirms the Paris Agreement
temperature goal of holding the increase in the global
average temperature to well below 2°C above
pre-industrial levels and pursuing efforts to limit thetemperature increase to 1.5°C above pre-industrial levels”
and “recognizes that the impacts of climate change will bemuch lower at a temperature increase of 1.5℃ comparedwith 2°C and resolves to pursue efforts to limit thetemperature increase to 1.5°C” (UNFCCC, 2021).
Pledging a net zero emission goal is a significant step
forward towards a safe climate. Meanwhile, to reach thelong-term goals, mid-term emission targets should also beambitious. Although many countries have revised theiremission targets for the year 2030, the total amount ofemission targets still overwhelms emission pathways forreaching the 1.5℃ goal.

2. Asia’s Important Role in Reaching 1.5℃
Asia accounts for a great share of the world in manyways. It represents about 60% of the global population insize (Worldometers, 2022). About half of global
greenhouse gases are emitted from Asia (UNEP, 2022).
Asia covers major emitters, including China, India,Indonesia, Japan and Korea. Therefore, Asia’scommitment to 1.5°C is a prerequisite for the world toreach that goal. Asia is already taking various actions toreduce emissions. As of August 2022, 39 out of 49
countries in the Asia-Pacific region have made carbon
neutrality and net-zero pledges, and have started
developing
enabling
frameworkstosupport
implementation of their commitments (United Nations etal., 2022). However, very few of these pledges aresupported by updated, ambitious mid-term emissioncommitments that will scale down greenhouse gas
emissions to keep global warming within the 1.5°C
pathway. This means that, once countries set long-termemission goals, it becomes important for them to set
ambitious mid-term emission reduction targets, andimplement sufficient policies to reach those targets (IPCC,2022).
The Asia-Pacific Integrated Model (AIM) is alarge-scale computer simulation model developed by theNational Institute for Environmental Studies (NIES) ofJapan, in collaboration with Kyoto University, Mizuho
Information & Research Institute and several research
institutes in the Asia-Pacific region. AIM assesses policy
options for stabilizing the global climate, particularly in
the Asia-Pacific region, with the objectives of reducing
greenhouse gas emissions and avoiding the impacts ofclimate change. An AIM team was established in 1990,
and has been networking with the team members in other
Asian countries. The AIM core team in Japan has long
been supporting the Japanese government in conducting
comprehensive assessment of emission reduction targets
whenever Japan needed to determine its emission
reduction targets. Today, Japan’s emission reduction target
for the year 2030 is “a 46 % reduction from the level ofthe year 2013 by 2030,” while further aiming at a 50%
reduction. The AIM team has been contributing by
developing options for reducing Japan’s greenhouse gas
emissions to achieve its emission targets for 2030, as wellas its net zero goal for 2050. Similar consultations arebeing made in other Asian countries by other AIM teammembers.
With the most recent modeling activities for the years
between 2020 and 2022 regarding emission pathways to
net zero goals, this special issue aims at bringing together
AIM team members from Asian countries. Each chapter
reveals today’s circumstances in an Asian country, andhow the country may be able to reach its net zeroemission goal. This special issue will contribute toenhancing the understanding of how Asia could arrive at

Editorial: Role of Asia towards a Decarbonized World

its net zero goals in the long-term while maintaining thewellbeing of its people and natural environment.

3. Structure of This Special Issue
This issue starts from assessment of potentials for useof renewable energy in Asia. This is mostly because
maximum use of renewable energy is indispensable to all
options for Asia to reach its net zero goals. Electricity canbe transferred across borders, so regional assessments for
Asia as a whole will be important for seeing how
renewable energy could be utilized in the most efficient
way in the region.
The following articles look into countries andeconomies in Asia: Japan, China, Indonesia, Thailand,Vietnam, Malaysia, Nepal, Laos and Taiwan. Eachcountry has its own national circumstances. Because net
zero goals need to be reached while the people are able tomaintain healthy daily lives, any emission reduction
policies must take into account non-climatesocio-economic issues in each country. A country-level
analysis is thus needed to merge emission reduction
policies with other policies.
Although countries face different issues at thedomestic level, all the countries covered in this issue havea firm determination to aim for net zero in the future.
Their national determination is supported by privatecompanies that invest in emission reduction projects.
Public-private partnerships will be effective towardrealization of a net zero society in Asia.

3Poverty. World Meteorological Organization.
IPCC (2022) Summary for Policymakers. In: Climate Change
2022: Mitigation of Climate Change, Contribution of Working
Group II to the Fifth Assessment Report of the Intergovernmental
Panel on Climate Change. Cambridge University Press.
United Nations (UN), the Economic and Social Commission for
Asia and the Pacific (ESCAP), United Nations Environment
Programme (UNEP) and United Nations Children’s Fund(UNICEF) (2022) 2022 Review of Climate Ambition in Asia andthe Pacific: Raising NDC Targets with Enhanced Nature-basedSolutions.
United Nations Environment Programme (UNEP) (2022)
Emission Gap Report 2022. Retrieved from https://www.unep.
org/resources/emissions-gap-report-2022 (accessed 28December 2022)
United Nations Framework Convention on Climate Change(UNFCCC) (2021) Decision 1/CMA.3 Glasgow Climate Pact,
FCCC/PA/CMA/2021/10/Add.1. Retrieved from https://unfccc.int/sites/default/files/resource/cma2021_10_add1_adv.pdf(accessed 28 December 2022)
United Nations Net Zero Coalition (2021) For a livable climate:Net-zero commitments must be backed by credible action.
Retrieved from https://www.un.org/en/climatechange/net-zero-coalition (accessed 28 December 2022)
Worldometers (2022) Population in Asia. Retrieved fromhttps://www.worldometers.info/world-population/asia-population/

Acknowledgments

Toshihiko MASUI

We would like to thank NIES “Decarbonized andSustainable Society Research Program” and Projects
1-2202 (JPMEERF20221002), 2-2002 (JPMEERF20202002) and 2-2102 (JPMEERF20212002) of theEnvironmental Restoration and Conservation Agency ofJapan (ERCA) for their research funding.

Toshihiko Masui is Director of Social Systems
Division at National Institute for Environmental
Studies (NIES), Japan. He has worked for thedevelopment and applications of the Asia-PacificIntegrated Model (AIM) especially focusing onclimate mitigation policy analysis modules formore than 25 years.

References
Borrell, J. (2020) China carbon neutrality in 2060: A possible
game changer for climate, European Union External Action,
Retrieved from https://www.eeas.europa.eu/eeas/china-carbon-neutrality-2060-possible-game-changer-climate_en (accessed 28December 2022)
Government of the United Kingdom (2019) UK becomes firstmajor economy to pass net zero emissions law, 27 June 2019.
Retrieved from https://www.gov.uk/government/news/uk-becom
es-first-major-economy-to-pass-net-zero-emissions-law(accessed 28 December 2022)
IPCC (2018) Summary for Policymakers. In: Global Warming of
1.5°C. An IPCC Special Report on the Impacts of Global
Warming of 1.5°C above Pre-industrial Levels and RelatedGlobal Greenhouse Gas Emission Pathways, in the Context ofStrengthening the Global Response to the Threat of Climate
Change, Sustainable Development, and Efforts to Eradicate

Yasuko KAMEYAMAYasuko Kameyama, Ph.D. is Senior Principal
Researcher at NIES. Her main field of study isinternational relations, and she has publishedmany journal articles on international negotiations
on climate change. She also works on sustainable
development indicators and measurements. She
serves as a member to various environmental
committees in national and local governments and in academic circles.

Kiyoshi TAKAHASHIKiyoshi Takahashi is Deputy Director of Social
Systems Division as well as Head of Economics
and Policy Studies Section in National Institutefor Environmental Studies (NIES), Japan. He has
engaged in the development of the Asia-PacificIntegrated Model (AIM) especially focusing on
climate impacts analysis modules for more than
25 years. In NIES, he is now leading a research project on strategies for
simultaneous achievement of global decarbonization and sustainability.