Extreme climate events increase risk of global
food insecurity and adaptation needs
Tomoko Hasegawa
Ritsumeikan Univeristy

The 28th AIM International Workshop

National Institute for Environmental Studies (Online)
September 13 and 14, 2022

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Topics• Effects of climate mitigation on food security• Reconciling growing food demand andenvironmental protection• Extreme climate events increase risk of global
food insecurity

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Emissions Pathways toward 1.5℃

GtCO2-eq/year

Global CO2 emissions pathways

Net negativeemissions
Net zero2050

2070• Net zero CO2– by 2050s toward 1.5℃
– by 2070s toward 2℃• Large negative emissions
are required in the latterof this century.
• BECCS orafforestation/reforestation
are main options
available for negativeemissions.

（Source）IPCC AR6 WG3 SPM Figure SPM.5 （Text and lines were added）

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Consequences of climate change and mitigation
on food security

Hasegawa et al., 2018

Global population at risk of hunger
Changes in population at riskof hunger (million)• Trade-offs between climatechange mitigation and foodsecurity• Economy-wide anduniform stringent climate
mitigation would negativelyaffect food security.
• Necessary to consider theadverse impacts andimplement complementarymeasures to reduce them.

Climate mitigation

Climate change

How do we meet growing food needs
while protecting the environment?
• The world trend is not on track to achieve the SDG Zero Hungertarget.

FAO (2021)

How do we meet growing food needs
while protecting the environment?
• The environmental impactsof food production required
to end hunger.

Food requirements to meet everyone’s needs• Increasing food production isa common approach but canpose environment risks.

+ 270Hasegawa et al., 2019

FFP+ALL

FFP + No Waste

FFP+ Improved yield

Crop yield improvement

FFP + No overcons

Reduced food over-consumption

Food for poor (FFP)

Reduced food waste

More food for all

Food support targeted to the poor

kcal/person/day-70

Business as Usual

Food policies

+ 750

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Impacts of food needs to end hunger
on the environmentMore food for All people
Food for poor only
+ 20％ Food production ↑+ 3％ food production ↑+ 48Mha Agricultural land ↑+ 550 MtCO2eq GHG emissions ↑Forest loss

Food for poor ＋ ALL policies- 9％ food production ↓- 230 Mha agricultural land ↓- 1360 MtCO2eq GHG emissions

GHG emissions Forest loss

GHG emissionsForest loss

Other
naturalNitrogen land loss
use

Other
naturalNitrogen land loss
use

Other
naturalland loss
Water use

Water use

GHG emissions

Nitrogenuse
Water use

Hasegawa et al., 20197

Extreme climate event increases risk ofglobal food insecurity and adaptation needs••••

Climate change can increase the frequency and intensity of extreme
climate event.
+ 11–36% of the world population may face hunger by 2050 under aonce-per-100-year extremely climate.
Globally the current total reserve is quantitatively sufficient, even in theworst case.
However, in some affected regions e.g., South Asia, the amount of foodrequirement to offset such an effect is triple the region’s current foodreserve.

Hasegawa et al., 2021

8Thoughts• Taking actions focusing on climate mitigation or implementing
global uniform emissions mitigation may cause adverse
impacts on low-income regions. Also, equally increasing foodconsumption for all people by 2030 would negatively affectthe environment.
• Therefore, achieving the SDGs requires an integrated strategy.
No single policy or effort is sufficient to achieve SDGs. It is
important to consider what kind of impact one measure will
have on another and then implement all related inclusive
policies and efforts.
• In future, we may face global food insecurity due to extreme
climate events and/or climate mitigation. Thinking about how
to address future global food insecurity in terms of global
collaboration and domestic food measures is of greatimportance.
9Thank you very much!

※ This work was supported by the Environment Research and Technology Development Fund(JPMEERF20202002 and JPMEERF20211001) of the Environmental Restoration and Conservation
Agency of Japan and JSPS KAKENHI (19H02273) of the Japan Society for the Promotion of Science,
the Ritsumeikan Global Innovation Research Organization (R-GIRO), Ritsumeikan University and theSumitomo Foundation.

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