29

Overview of Studies in Japan on Climate Change Impacts
and Adaptation : Towards Climate Risk Management
Based on Scientific Evidence
Kiyoshi TAKAHASHINational Institute for Environmental Studies (NIES)
16-2, Onogawa, Tsukuba, Ibaraki, 305-8506, Japane-mail:ktakaha@nies.go.jp

Abstract
Persistent efforts to improve scientific understanding of climate risks and countermeasures against them
are indispensable for keeping strong momentum of coordinated climate risk management efforts. For
example, the long-term climate target for the global mean temperature increase from the pre-industrial periodof less than 2 degrees Celsius in the Paris Agreement is not fresh-off-the-farm but has a long history ofpolitical discussion supported by the science available at any given time. On another front, Japan publishedits first national adaptation plan in November 2015. When we look at domestic climate policies, rapidly
growing attention to adaptation in Japan also revolves around the intensified public perception of existing
and anticipated climate impacts. Based on the above, the primary purpose of this article is to give an
overview of previous, ongoing and future studies on climate impacts and adaptations in Japan with regard todomestic and international policy support. This overview of the studies provides suggestions for some
important directions or aspects of future research on climate risks. These include the importance of co-designand co-production in fields of study to support decision making and strategy planning against global
environmental problems; improvements to quantification and communication of uncertainties in climate risk
analyses; the importance of participation in internationally coordinated research activities, including impact
model inter-comparison projects; archiving and management of tools and data developed for risk analysis for
portability and transparency; and responsibility of researchers in the iterative process of periodic climate risk
assessment.
Key words: adaptation, climate change impacts, risk management, long-term target, sustainability

1. Introduction
Persistent efforts to improve scientific understandingof climate risks and countermeasures against them areindispensable for keeping strong momentum of
coordinated climate risk management efforts. The Paris
Agreement, agreed upon among the parties to the
UNFCCC (United Nations Framework Convention on
Climate Change) in December 2015 and effective from
November 2016, explicitly manifests its central aim forstrengthening the global response to the climate change
threat by keeping the global temperature rise this century
well below 2 degrees Celsius over pre-industrial levels
and to pursue efforts to limit the temperature increase
even further to 1.5 degrees Celsius. This long-termclimate target is not fresh-off-the-farm but has a long
history of political discussion supported by the best
science available at any given time. Most recently, thereferential scientific treatises include the Fifth Assessment
Report of the IPCC (Intergovernmental Panel on Climate
Change) published in 2013-2014 and further scientific
Global Environmental Research
21/2017: 029–037
printed in Japanevidence communicated between researchers andpolicymakers at the SED (Structured Expert Dialogue)
process for the periodic review of the long-term target by
the UNFCCC (Fig. 1, a chronological summary of eventson international/domestic climate policy and relevant
research projects in Japan, that are discussed in thisarticle).
If we look at domestic climate policies, rapidly
growing attention to adaptation in Japan also revolves
around the intensified public perception of existing andanticipated climate impacts. In November 2015, theJapanese government formulated its first national plan
for adaptation to the impacts of climate change (NAP)
with the purpose of promoting adaptation to climatechange impacts systematically and comprehensively.
Prior to the NAP’s formulation, the Central Environment
Council (an advisory body of the Japanese Cabinet)
assessed the existing and potential impacts of climatechange on seven major sectors (agriculture, forestry andfisheries; aqueous environments and water resources;
natural ecosystems; natural disasters and coastal areas;©2017 AIRIES

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K. TAKAHASHI
Climateprojection

Innovative program ofclimate change projection
for the 21st century(KAKUSHIN)

Globalclimate risk
analyses

Integrated research on
climate scenarios forpolicy support and publicawareness (GERF S-5)

Climateimpacts inJapan

Integrated Climate
Assessment ‒ Risks,
Uncertainties andSociety (GERF S-10) Strategic research on
global mitigation and local
Comprehensive study
adaptation to climate
on impact assessmentchange (GERF S-14)
and adaptation(GERF S-8)

Comprehensive
projection of climatechange impacts(GERF S-4 )Research programon climate change
adaptation (RECCA)

Regional
adaptation
IPCC reports and
UNFCCC agreements
Governmental
reports and policies
Information
platform
2005

Research program for
improving integrated
climate models(TOUGOU)

Program for
information on
climate changerisks (SOUSEI)IPCC-AR4Social implementation programon climate change adaptation
technology (SI-CAT)

IPCC-AR5
Copenhagen Accord &Cancun Agreements

ʻWise
Adaptationʼ
reportSED

ʻSynthesis Reportʼ in2009 and 2012
Portal site on climate
impacts statistics

2010

Paris
Agreement
1st NAP

Facilitative
dialogue

Report on science
to support NAP

A-PLAT (Climatechange adaptation
platform)
2015

AP-PLAT (AsiaPaciﬁc adaptation
info. platformʼ)2020

Fig. 1 Chronological summary of international/domestic climate policy events and relevant research projects in Japanthat are discussed in this article.

human health; industrial and economic activities; livesof citizenry and urban life) and compiled the Report on
Assessment of Impacts of Climate Change in Japan and
Future Challenges in March 2015 with the participationof academic experts from a broad range of disciplines.
The first NAP emphasized continuous enhancement ofscientific findings, as one of the basic strategies it listed,through implementation of observation and monitoring,projection and assessment, and promotion of studies andresearch. Based on the first NAP, the Central Environment
Council discussed governmental efforts necessary forsupporting a review of climate risk assessment planned
before or around 2020 and published an interim report
titled Policies and Procedures for Efforts on Scientific
Knowledge and Climate Risk Information to Promote
Climate Change Adaptation in March 2017.
Based on the information noted above, the primary
purpose of this article is to provide an overview ofprevious, ongoing and future studies on climate impacts
and adaptations in Japan with regard to domestic andinternational policy support. Section 2, below, provides abrief review of previous major scientific efforts (relatively
large research projects) on climate change impact andadaptation analysis. Section 3 explains urgent research
themes for supporting adaptation policy that have been
identified in recent reports by the Central Environment
Council. Section 4 introduces ongoing activities of new
research on impacts and adaptation in Japan. Lastly,
Section 5 concludes the article with a discussion ofprospects for impact and adaptation studies in Japan.

2. Previous Climate Impact and Adaptation
Analysis Efforts in Japan
While impact studies on specific sectors alreadyexisted in 1990s, coordinated analyses of climate
impacts on comprehensive sectors in Japan didn’t
emerge until FY2005. As a research project funded by
Japan’s Ministry of the Environment (MOE). The
project, titled “Project for Comprehensive Projection of
Climate Change Impacts” (commonly known as the“GERF S-4 project”; FY2005-2009) contained a wide
range of research teams from national research institutes
and universities and conducted coordinated scenario
analyses of climate impacts on water resources, humanhealth, agriculture, ecosystems, and natural disasters. Key
findings of the project were summarized in two research
reports published in 2008 and 2009 (http: / / www.nies.
go.jp/s4_ impact/English/seika-e.html), and were alsoutilized intensively in a ministerial report of the MOE,
titled Wise Adaptation to Climate Change―Report by
the Committee on Climate Change Impacts andAdaptation Research, published in June 2008 (http: / /www.env.go.jp/en/earth/cc/wacc_080618.pdf).
The basic research structure of the GERF S-4 project
was taken over by the succeeding project, called the“GERF S-8 project” (“Comprehensive Study on Impact
Assessment and Adaptation for Climate Change”;
FY2010-2014) funded by the MOE for further emphasison adaptation analysis and explicit consideration of
future climate uncertainty. In parallel with the GERF S-8

Overview of Studies in Japan on Climate Change Impacts and Adaptation

project, the RECCA project (“Research Program on
Climate Change Adaptation”; FY2010-2014; https: / /www.restec.or.jp/recca/eng/) funded by the Ministry of
Education, Culture, Sports, Science and Technology(MEXT) tackled sophistication of adaptation analyses in
specific regions and sectors for supporting decision
makers in local governments. In addition to the research
projects noted above, progress was achieved towardsophistication of hazard analyses relevant to natural
disaster prevention mainly by the KAKUSHIN program(“Innovative Program of Climate Change Projection forthe 21st Century”; FY2007-2011) and the succeeding
SOUSEI program (“Program for Risk Information on
Climate Change”; FY2012-2016) funded by MEXT
under a strong partnership with global/regional climate
modeling teams in Japan. The research findings obtained
through the projects above conducted during this decadewere intensively utilized in compiling the Central
Environment Council report published in March 2015
and the first NAP published in November 2015, both ofwhich were mentioned above.
For global scale analyses of climate change impacts, inthe 1990s, there were a few sectorial analyses in Japan,
some of which were conducted for the development of a
global integrated assessment of climate policies (e.g.,Harasawa et al., 2003). The GERF S-5 project (“Integrated
Research on Climate Scenarios for Policy Support andPublic Awareness”; FY2006-2010) made the first effort
toward coordinated analyses of global climate impacts inJapan, aiming to interpret the latest climate projections
available during the period to depict expected climate risks
mainly to natural systems. The GERF S-5 project’s risk
analyses highlighted uncertainty in the climate projections
and the implications regarding future climate impacts.
Some of the global climate risk analyses in the GERF S-5
project were succeeded by the GERF S-10 project(“Integrated Climate Assessment – Risks, Uncertainties
and Society (ICA-RUS)”; FY2012-2016; https://www.
nies.go.jp/ica-rus/en/index.html), where they were mademore comprehensive for discussing and developing
global climate risk management strategies. The primary
purposes of the GERF S-10 project included comparing(i) sector climate risks expected under the long-termclimate targets for global mean temperature increases
from the pre-industrial period not exceeding 1.5, 2.0 or
2.5 degrees Celsius and (ii) mitigation efforts required
for achieving these respective targets.
The large research projects presented above tended
to be self-contained and were conducted independently
without substantial collaboration with other research
projects. That may have resulted in inefficiencies suchas duplicated data collection that might have been
avoided through cooperative efforts. This deficientcollaboration was more remarkable among projects
funded by different ministries or funding agencies. Someconcrete measures have been tried for enhancing organic
integration of projects. One was establishment of a task
group for climate scenarios, which was co-managed by
the MOE-funded GERF S-5 project (risk analyses) and

31

MEXT-funded
KAKUSHIN
Program(climate
projections). The task group was expected to support
efficient data transfer from the climate modelingcommunity to the impact projection studies. Periodic
task group meetings were held for exchanging the latest
research information and discussing the efficient sharing
and transfer of large archives of climate model outputs.
Publication of Synthesis Report on Observations,
Projections, and Impact Assessments of Climate Change－Climate Change and its Impacts in Japan in 2009 and2012 through inter-ministerial collaboration among theJMA (Japan Meteorological Agency), MEXT and MOE
also worked as a link for improving organic connections
among the research projects funded by any of thoseministries/agencies.

3. Urgent Research Themes Identified inGovernmental Committee Reports
As discussed in Section 2, major governmental
reports on adaptation policy have tended to be linked
with and based on outputs of the coordinated research
projects for studying multi-sector impacts at thenational/local scale. The first NAP stresses theimportance of improved scientific evidence forsupporting periodic climate risk assessment, and theinterim report (Policies and Procedures for Efforts on
Scientific Knowledge and Climate Risk Information to
Promote Climate Change Adaptation), which wascompiled in March 2017 as a follow-up activity to the
NAP, suggested research themes and areas that should
be prioritized for supporting periodic risk assessment.
While not all the suggestions derived from politicalneeds may be realized due to limited financial andtechnical resources, the suggestions in the report willaffect the direction of research conducted in Japan in the
coming years. Thus this section summarizes the urgent
research themes indicated in the committee report.
The report advises the Japanese government topromote climate change risk analysis and implement
adaptation through cooperation among relevant ministries
and partnerships with a wide range of stakeholders. The
MOE has been advised by the report to work on (1)enhancement of scientific knowledge, (2) promotion ofunderstanding and cooperation of stakeholders throughthe effective provision of climate risk information, (3)promotion of adaptation policy at a regional scale, (4)promotion of international cooperation and contribution.
More specifically, regarding (1), enhancement ofscientific knowledge, the following five policy directions
are presented.
i.	Continual observation and monitoring of climatechange and its impacts-	
Review of climate impact observation andmonitoring of implementation plans by relevant
ministries-	
Securing long-term sustainable observation/
monitoring activities supporting adaptation plan

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K. TAKAHASHI

implementation
ii. Projection of climate change and its impacts-	Review of climate scenarios and other settings for
impact projections by relevant ministries-	
Promotion of studies on tools for developing
national/regional SSPs that are consistent with
global SSPs
iii.	Enhancement of investigative research on climate
impacts-	Promotion of studies to develop indices andmethods for evaluating vulnerability, exposureand adaptive capacity-	
Promotion of assessments of vulnerability andexposure at a regional scaleiv.	Evaluation of effects of overseas climate impacts on
Japan
-	
Investigative
research
focusingontheinternational supply chain and global food demandand supply
v. Periodic assessment of climate risks-	Collection and transmission of the latest scientificknowledge on sector impacts through theestablishment of expert working groups in aplanned and consistent way-	
Improvement of evaluation criteria forsignificance, urgency and confidence of climate
risks based on new scientific findings, as neededWith regard to policy direction (i) itemized above,for prioritizing, promoting and realizing adaptations
urgently needed for mitigating climate risks in sensitive
sectors, an accurate understanding of the present stateof vulnerability and exposure as well as hazards is
crucial. Scientific evidence of emerging climate impacts
would be a strong motivation for people and society to
implement the necessary urgent adaptation measures.
Moreover, continuous monitoring of relevant factors forclimate risks will be crucial for enhancing
understanding of the problems’ mechanisms, which
would also increase public perception of the problems
and promote implementation of the measures. Among
various governmental policies regarding observationand monitoring of changes in the natural environment
and ecosystems, “Monitoring Site 1000” (http://www.
biodic.go.jp/moni1000/) and “Ikimono-Log” (https: / /ikilog.biodic.go.jp/) operated by the MOE are unique
for their reliance on reporting by non-experts as well as
experts to increase the temporal and spatial coverage ofmonitoring as well as the sense of participation by the
stakeholders. Under “Monitoring Site 1000,” the MOE
set up about 1000 locations for long-term monitoring ofvarious types of ecosystems and is trying to catch
quantitative and qualitative deterioration of naturalenvironment at an early stage. For sustainable long-term
observation, networks among universities, research
institutes, experts, regional NPOs and volunteers havebeen constructed, and monitoring activities are being
implemented. The collected data are processed andpublicized swiftly for enhanced information sharing

among stakeholders and expedited conservation actions.
A portal website for statistics relevant to climatechange impacts (http://www.nies.go.jp/occco/statistics_
portal/index.html) is also operated by the MOE with thesupport of the OCCCO (Office for Coordination of
Climate Change Observation) at NIES (National Institutefor Environmental Studies). The portal site wasdeveloped and launched based on recognition thatclimate change impacts had already been manifesting inmany places and sectors and it was important to detect
those manifesting impacts quickly enough for the
purpose of adapting to them in a timely manner. With thecooperation of relevant ministries and agencies, statistical
data recorded and consolidated by various institutions fortheir own respective purposes are collected extensively
from the viewpoint of relevance to climate impacts andput in order at the portal site. The data list in the portalsite contains not only statistical data on impacts directly
attributed to recent climate change but also otherstatistical data that may be informative for understanding
climate change impacts better. Continuous updating of
the list is planned.
Policy direction (ii) highlights proper formulation of
scenarios for climate, socio-economic and otherenvironmental factors to be assumed in impact
projections. For global or terrestrial climate scenarios,
not only climate projections with the domesticallydeveloped global climate models but also climate
projections supplied by the foreign modeling teams need
to be collected, evaluated and utilized efficiently. For
impact analyses targeting Japan, spatial downscaling is a
key procedure and should be carefully considered. Whileregional climate models have been improved steadily
during recent decades, how to process the outputs ofregional climate models is also a crucial consideration
for developing climate scenarios suitable to each impact
analysis.
Development of national/regional socio-economic
scenarios for assuming future vulnerability and exposureis also an urgent task, since it will be an importantelement in coordinated climate risk analyses. For global
scale impact analysis, SSPs (Shared Socio-economic
Pathways) have been developed to be commonly used,especially in research aiming at contributing to
IPCC-AR6 (Riahi et al., 2017). National/regional socioeconomic scenarios do not necessarily need to beconsistent with the global SSPs. If consistency ismaintained, however, the results of climate risk
assessment in Japan can be better linked or comparedwith global assessments or assessments conducted inother countries based on similar assumptions. Whiledeveloping quantitative downscaling methods forland-use, population and other factors is essential todevelopment of a national/ regional socio-economic
scenario, bottom-up visioning of the future by local
stakeholders and experts is also valuable and should beconsidered. Regarding the downscaling of the SSPs,
some precedent research exists, conducted mainly byresearch teams in Europe and the U.S. (e.g., Absar &Overview of Studies in Japan on Climate Change Impacts and Adaptation

33

Fig. 2 Risk of climate-related impacts resulting from the interaction of climate-related hazards (including
hazardous events and trends) with the vulnerability and exposure of human and natural systems.
Changes in both the climate system (left) and socioeconomic processes including adaptation andmitigation (right) are drivers of hazards, exposure and vulnerability. (Adapted from IPCC (2014))

Fig. 3 I llustration of the dependence of risks associated with a “reason for concern” (RFC) on the level of climate change and the exposureand vulnerability (E&V) of society.
	Left (a): dependence of risk associated with RFCs on the level of climate change assessed in IPCC-AR5, which does not explicitly
express dependency of risk on E&V. Right (b): Schematic figure illustrating the idea of extending the ordinary RFC diagram (left) toconsider E&V dependency explicitly. “Medium” E&V indicates a future development path in which E&V changes over time are
driven by moderate trends in socioeconomic conditions. “Low” and “High” E&V indicate futures that are substantially more optimistic
or pessimistic, respectively, regarding exposure and vulnerability. (Adapted from Figs. 19-4 and 19-5 in Oppenheimer et al. (2014) )Preston, 2015).
Regarding policy direction (iii), more attention has
been paid recently to the need for research on vulnerability
and exposure with relevance to development of national/
regional socio-economic scenarios as mentioned above.
While there have been many projections of impacts onnatural systems such as hydrological state, vegetationand crop yields so far, climate impacts on social systems
have been less studied and understood. Even inprojections of socio-economic impacts, there has been atendency to assume that vulnerability, exposure andrelated adaptive capacity remain constant (no change in

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K. TAKAHASHI

the future from the present state).
This limited consideration of future change in socioeconomic conditions is not merely the case just in Japanbut more universally. IPCC-AR5 highlighted theimportance of considering vulnerabilities and exposure
for assessing and managing risks (Fig. 2; IPCC, 2014) as
well as hazards. The Reasons for Concern (RFC)
diagram was also claimed to be improved by considering
future change and uncertainties in vulnerabilities andexposure more explicitly (Fig. 3; Oppenheimer et al.,2014). The determination of key risks as reflected in the
RFCs has not previously been distinguished acrossalternative development pathways (left plate in Fig. 3).
The RFCs, however, represent risks that are determinedby both climate-related hazards and the vulnerability andexposure of social and ecological systems to climatechange stressors.
The right plate in Fig. 3 illustrates this dependence
on vulnerability and exposure in a modified version of
the burning embers diagram. Literature published before
IPCC-AR5 (before 2014) was insufficient for supporting
confident assessment of specific RFCs using theillustrated approach. While this limitation has been amajor concern for many years, intensive efforts toovercome it will be made with support of the SSPs in
the years to come before the next IPCC-AR6. Not being
left behind by the international frontline of research
efforts is quite important to the Japanese researchcommunity for attaining proper, realistic adaptation
policies as well as for increasing its presence in theinternationally competitive research community.
Policy direction (iv), evaluating the effects ofoverseas climate impacts on Japan, poses a traditionalfrequently asked question that has yet to be answered
sufficiently. Conceptually, this type of risk was already aconcern even at the initial stage of climate policy
discussion. A typical example is the effect of crop yieldchanges in other countries which are propagated throughinternational food trade. However, after Thailand
experienced a huge flood in 2011 causing severe
disruption to international industries, including global
car manufacturers, people began calling for a more
serious discussion. The fragility of the global
commercial supply chain was recognized more
concretely than before. Beyond the hypothetical andqualitative indications of indirect potential risks from
impacts outside Japan, quantitative analyses need to be
improved. Recently, impacts on national security
affected by changes in migration patterns caused byclimate change and rising occurrences of conflicts
caused by increases in extreme climate events have also
been a concern (e.g., Burke et al., 2015). From thepractical viewpoint of model simulation, coherent
downscaling of the climate and socio-economic
scenarios discussed above is also related to thefeasibility of the analyzing knock-on effects of climatechange impacts in other countries on Japan.
Finally, regarding policy direction (v), as found in
the IPCC process for global circumstances, it should be

remembered that promotion of academic research andperiodic scientific assessment of available knowledge
are interdependent. Since researchers know that research
results are surveyed and assessed periodically forsupporting policymaking processes, they can plan theirresearch so that it will be useful and timely for those
processes.
Otherwise,
without
theimproved
understanding provided by the research, periodic climate
risk assessment cannot be conducted effectively. The
explicit signal from the government that suggests a needfor periodic assessment of the latest scientificunderstanding will increase motivation among
researchers to conduct relevant studies, especially if thesignal is embodied within prioritized provision ofresearch funding. Regarding improving evaluation
criteria for climate risks, continuous efforts to improverisk communication based on stakeholders’ views will
become more important.
To promote the understanding and cooperation of
stakeholders through the effective provision of climate risk
information, prioritized policy (2) listed above, the A-PLAT(“Climate Change Adaptation Platform”; http: / / www.
adaptation-platform.nies.go.jp/en/index.html) establishedby the MOE in 2016 is expected to function as a bridge
for interactive communication between the science
community, which provides evidence, and stakeholders
such as public citizens, the private sector and local
governments. The platform is designed to contain andprovide data and tools for supporting adaptation
decisions, like simplified climate risk models and risk
maps. It also contains guidance materials for promoting
adaptation actions by individual stakeholders, includingsummary reports of good practices in the private
business sector. The platform is also planned to beequipped with the additional function of supporting
adaptation policy developments in developing countries
in the Asia-Pacific region, to be extended to the
AP-PLAT (“Asia-Pacific Adaptation Information
Platform”) by 2020, based on the statement by Ministerof the Environment Koichi Yamamoto at COP22 in 2016
on support from Japan’s government for thedevelopment of infrastructure to share climate risk
information regionally. In a word, any adaptation-related
studies conducted in Japan are encouraged to utilize theplatform as an outlet for research deliverables, and thiswill surely affect research proposals on adaptation issues
in the coming years.
Other policy initiatives related to enhancing
adaptation at a local scale as well as in developing
countries in the Asia-Pacific region also give researchers
full play. For example, promotion of adaptation at a
local scale will be supported by the “Consortiums for
Local Scale Adaptation,” consisting of the national
government, local authorities and research organizations.
The consortiums are expected to conduct climate risk
analyses based on collaboration among relevant
stakeholders and evidence-based adaptation planning. It
would be quite a new challenge for researchers to workon research themes based on direct discussion andOverview of Studies in Japan on Climate Change Impacts and Adaptation

collaboration with potential audiences (i.e., co-designand co-production proffered in FutureEarth). A similar
approach is also applicable to collaborative work with
Asia-Pacific countries. For example, some projects forsupporting adaptation policy planning in Asia-Pacificcountries have been conducted through collaboration
among local stakeholders who have the ability to affectlocal policies, local researchers who understand the local
problems best and have good access to proper data, andexperts from Japan who bring tools like impact analysis
models as introduced in Section 4.

4. New and Ongoing Research Projects on
Climate Impact and Adaptation Analysis
Here, it is worth summarizing ongoing major
research projects on climate impacts and adaptation to
get an overview of present research interests anddirections in Japan and to consider their potential
contribution to achievement of the Paris agreement.
Regarding global-scale analyses of climate impacts,
the GERF S-14 project (“Strategic Research on Global
Mitigation and Local Adaptation to Climate Change”;
FY2015-2019; http://s-14.iis.u-tokyo.ac.jp/eng/) fundedby the MOE has been working on analysis of mitigation
and adaptation in an integrated manner. It also contains
a research module that aims at linking a global economic
model (AIM-CGE) with sector impact models toimprove economic analysis of climate change impacts.
For example, Takakura et al. (2017) estimated theeconomic cost of heat-related illness prevention throughworker breaks associated with climate change under awide range of climatic and socioeconomic conditions
using the AIM-CGE linked with a worktime reduction
impact model. The study showed that GDP losses in
2100 will range from 2.6 to 4.0% compared to thecurrent climate conditions under the highest emission
scenario while the losses could be less than 0.5% if the
2.0° C goal is achieved. To discuss long-term climate
targets and mitigation pathways, accurate economic
analysis of climate change impacts will be crucial. The
analyses’ comprehensiveness (coverage of the impacted
sectors), however, is still insufficient for such a
discussion. By expanding the sectors for which
economic impacts can be estimated, studies conductedby the project will be able to contribute to policy
discussions of long-term global climate targets. The
project also aims at better consideration of adaptation in
impact projections, so it would fill one of the key
research gaps in this research field.
The SI-CAT program (“Social Implementation
Program on Climate Change Adaptation Technology”;
FY2016-2020; https://si-cat.jp/en/staticpages/index.php/
about) funded by MEXT collaborates with local
governments in developing technologies thatcomprehensively assess precise near-term climate
projections and the effectiveness of countermeasuresagainst climate change impacts in Japan, consideringrespective regional characteristics. The keyword and35

ultimate target of the project is “social implementation.”
It aims at either avoiding or reducing the damage causedby climate change by reflecting these technologies inplanning for urban development, agriculture and otherindustries. The SI-CAT program conducts technologicaldevelopment to find adaptation measures needed for the
future in collaboration with researchers in geoscience,social science and the humanities, and officials of local
governments for protecting the security of residents andtheir property from climate change threats. It willcontribute to the development of adaptation plans bylocal governments and the creation of new enterprises inconsideration of steady adaptation of various needs toclimate change.
As discussed in Section 2, improvement of climate
models and future climate projections have been
conducted mainly in successive large research projects
supported by MEXT. The latest ongoing project is called
the TOUGOU Program (“Research Program for
Improving Integrated Climate Models’), which waslaunched very recently in May 2017. The program
consists of four research themes: global climate
projection and development of basic models for the
projection, improved understanding of the carbon cycle
and climate sensitivity, integrated projection of climatechange, and integrated projection of hazards. This
research program can be considered a successor to
MEXT-funded research projects for the development andimprovement of climate models that have utilized theEarth Simulator (high-speed super computer) since
FY2002. After several system updates to reflect computer
technology improvements, the ES3 (the 3rd generation
Earth Simulator) has been operational since June 2015.
Based on the accumulated research knowledge andresources, the new program is going to tackle novel tasks
such as provision of climate projections suitable foradaptation analyses with fine spatial resolution (a fewkm); decreasing the uncertainty regarding the carbon
cycle, nitrogen cycle and climate sensitivity so that ascientific basis can be formed for mitigation policy; andgaining further insight into tipping elements. These newfeatures would be useful for supporting the developmentof national disaster prevention plans and ambitious
mitigation policies. It is also worth noting that the project
also aims at producing climate projections useful forassessing adaptation not only inside Japan but in other
East Asian countries, following governmental policy tosupport adaptation in the region.
Here, let us also look at existing or anticipatedinternational collaboration. For global scale analyses ofclimate impacts, the importance or necessity ofparticipation in model inter-comparison projects is
becoming well recognized in Japan as well. For example,
four Japanese impact models were considered in the fasttrack analyses of the ISI-MIP project (Inter-Sectoral
Impact Model Inter-comparison Project) and contributed
to papers surveyed in IPCC-AR5 (Warszawski et al.,2014). Furthermore, in ongoing consecutive rounds ofthe project, larger number of Japanese modeling teams

36

K. TAKAHASHI

are participating. It seems that uncertainty in impact
projections caused by the choice of analytical methods(models) have been proven to be no less than theuncertainty caused by future climate and socio-economic
scenarios. As previously experienced in the global
climate model development process, engagement ininternational model inter-comparison projects will bebeneficial for providing insight into the frontline of theresearch. It will also increase the presence of theparticipating modeling teams in the international
academic community.
Contribution to the IPCC is highly recognized in theJapanese research community. This should not be limited
to elevating active researchers to the report writing
teams, but there should be various other ways tocontribute as well. Generally, research funds granted bygovernment ministries require the recipients to produce
output that directly benefits the ministerial services. In
some cases, however, citations of published literature by
IPCC reports are also highly appreciated as contributing
to a governmental service, as they may be consideredinternational contributions from the Japanese
government.
As discussed in Section 3, support of Asia-Pacificcountries for policy planning and implementing
adaptation is also a prioritized policy direction explicitly
mentioned in the first NAP. Concrete policy actions havebeen initiated as a follow-up to the NAP. The plan oflaunching the AP-PLAT introduced in Section 3 is oneof the typical efforts for supporting adaptation policies
in these countries. Bilateral collaborative projects arealso being conducted for adaptation analysis, planningand implementation.

5. Conclusion
The above-given summary of recent research
activities on climate risk analysis, brought up some
important directions or aspects of future research.
First, “co-design” and “co-production,” highlighted
in FutureEarth, are becoming more and more importantin the field of study to support decision making andstrategy planning in response to global environmental
problems (as discussed in Section 3). They also apply to
climate risk analysis and adaptation assessment.
Involvement of stakeholders at the initial stage of
research planning is crucial. This might not be achieved
effectively by voluntary efforts of researchers alone, andresearch funding systems may also need to change topromote interaction between the research communityand potential study audiences.
Second, while quantification and communication of
uncertainties in climate risk analyses have become better
recognized in the previous decade, further improvement
is still needed. The availability of new scenarios such as
SSPs for socio-economic change and new climate
scenarios will help us analyze future uncertainties in amore comprehensive manner (as highlighted also in theinterim report introduced in Section 3). Spatial

downscaling of those global scenarios to national/local
scale impacts and adaptation analyses will also be
important.
Third, there are internationally coordinated activities
aiming to improve impact analysis and adaptationassessment, which include model inter-comparison
projects (as discussed in Section 4). Constant active
participation in such activities would increase the qualityof risk analysis conducted in Japan, which would
ultimately increase their international presence. As ashorter-term task, contribution to scientific assessments
conducted by the IPCC and dialogues between
policymakers and researchers in the UNFCCC may beprioritized, since they can provide direct input tointernational negotiation processes. What would be evenmore beneficial would be to contribute during theframing stage of internationally coordinated activities.
Fourth, climate risks and adaptation options needed
for managing the risks are generally region-specific andneed to be analyzed considering individual and uniquelocal conditions. Tools, models and some types of datafor quantitative analysis of the risks, however, could be
generic to some degree. For efficiently increasing thecoverage of analyses, tools and data developed andaccumulated during the process of adaptation analysis ina specific region should be archived and maintained
properly to be utilized for analyses in other regions.
Such an archive of tools and data would be also effective
for maintaining scientific rigor by increasing thefeasibility of their validation. Previously, it often
occurred that tools and data developed in a research
project or governmental survey were not maintained
very well after the project ended and valuable products
were not efficiently used again. Fortunately, it seems
ongoing large research projects and policy initiatives fordata management and distribution (e.g., A-PLAT,
explained in Section 3) have been conducted with more
careful consideration to data management issues.
Finally, the first national adaptation plan has explicitly
shown a need for periodic risk assessment based on thebest tools and data available in each period. Researchers
are expected to support the process through sustainable
efforts for improving risk assessment methods. To
improve the performance of analyses, it is naturally the
responsibility of researchers to develop and improveanalytical tools such as more accurate and precise impact
simulation models. More active participation ininternational model comparison may be an effective stepfor steady improvement of analytical methods as
discussed above. Long-term, continuous, repetitive
investigation using the tools developed may not be
considered academic research, but it might be consideredroutine investigation or a monitoring task. Appropriate
interpretation of long-term repetitive assessments,
however, will be a situation where researchers’ expertiseis crucial.

Overview of Studies in Japan on Climate Change Impacts and Adaptation

37

Acknowledgment
This article is based on the results of multiple research
projects including the Environment Research andTechnology Development Fund (S-14-5 and S-10) of theEnvironmental Restoration and Conservation Agency.

References
Absar, S.M. and B.L. Preston (2015) Extending the Shared
Socioeconomic Pathways for sub-national impacts, adaptation,and vulnerability studies. Global Environmental Change, 33:
83–96.
Burke, M., S.M. Hsiang and E. Miguel (2015) Climate andconflict. Annual Review of Economics, DOI: 10.1146/annureveconomics–080614–115430.
Harasawa, H., Y. Matsuoka, K. Takahashi, Y. Hijioka, Y. Shimada,Y. Munesue and M. Lal (2003) Potential impacts of global
climate change. In: M. Kainuma, Y. Matsuoka and T. Morita
eds., Climate Policy Assessment Asian-Pacific Integrated
Modeling, Springer, 37–54.
IPCC (Intergovernmental Panel on Climate Change) (2014)
Summary for Policymakers. In: C.B. Field, V.R. Barros, D.J.
Dokken, K.J. Mach, M.D. Mastrandrea, T.E. Bilir, M. Chatterjee,
K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel,
A.N. Levy, S. MacCracken, P.R. Mastrandrea, and L.L. White,eds., Climate Change 2014:
Impacts, Adaptation and
Vulnerability. Contribution of Working Group II to the Fifth
Assessment Report of the IPCC, Cambridge Univ. Press: 1–32.
Oppenheimer, M., M. Campos, R. Warren, J. Birkmann, G. Luber,
B. Oneill and K. Takahashi (2014) Emergent Risks and Key
Vulnerabilities. In: C.B. Field, V.R. Barros, D.J. Dokken, K.J.
Mach, M.D. Mastrandrea, T.E. Bilir, M. Chatterjee, K.L. Ebi,
Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy,
S. MacCracken, P.R. Mastrandrea and L.L. White, eds.,
Climate Change 2014: Impacts, Adaptation and Vulnerability.
Part A: Global and Sectoral Aspects. Contribution of Working
Group II to the Fifth Assessment Report of theIntergovernmental Panel on Climate Change, Cambridge Univ.
Press: 1039–1099.
Riahi, K., D.P. van Vuuren, E. Kriegler, J. Edmonds, B. O’Neill,
S. Fujimori, N. Bauer, K. Calvin, R. Dellink, O. Fricko, W. Lutz,
A. Popp, J.C. Cuaresma, M. Leimbach, T. Kram, S. Rao,
J. Emmerling, T. Hasegawa, P. Havlik, F. Humpenöder, L.A.
Da Silva, S. Smith, E. Stehfest, V. Bosetti, J. Eom, D. Gernaat,
T. Masui, J. Rogelj, J. Strefler, L. Drouet, V. Krey, G. Luderer,
M. Harmsen, K. Takahashi, M. Wise, L. Baumstark, J. Doelman,
M. Kainuma, Z. Klimont, G. Marangoni, R. Moss,
H. Lotze-Campen, M. Obersteiner, A. Tabeau and M. Tavoni(2017) The Shared Socioeconomic Pathways and their energy,
land use, and greenhouse gas emissions implications: An
overview. Global Environmental Change, 42: 153–168.
Takakura, J., S. Fujimori, K. Takahashi, Y. Hijioka, T. Hasegawa,Y. Honda and T. Masui (2017) Cost of preventing workplaceheat-related illness through worker breaks and the benefit ofclimate-change mitigation. Environmental Research Letters,
12(6): 64010.
Warszawski, L., K. Frieler, V. Huber, F. Piontek, O. Serdeczny and
J. Schewe (2014) The Inter-Sectoral Impact Model
Intercomparison Project (ISI–MIP): Project framework. PNAS,
111(9): 3228–3232.

Kiyoshi TAKAHASHI
Kiyoshi Takahashi has a PhD in Engineering. His
major areas of expertise include environmental
system modeling. Since starting work at NIES in
1996, he has been engaged in the development of
AIM (Asia-Pacific Integrated Mode), an integrated
assessment model for climate policy analysis, andhas contributed to improvement of the global climate
impact analysis modules within it. Recently, his greatest interest is in policies
and measures for achieving both long- term climate targets like the Paris
Agreement and sustainability targets represented simultaneously by the
Sustainable Development Goals. He has taken the role of lead author in boththe 4th and 5th IPCC assessment reports.

(Received 22 June 2017, Accepted 27 August 2017)