The Japan Forum on International Relations

June 02,2023

Climate Security and Japan

The G7 Hiroshima Summit Session 7 “Common Endeavor for a Resilient and Sustainable Planet” addressed the importance of understanding energy security, climate crisis, and geopolitical risks in an integrated manner.

The National Security Strategy of Japan, revised in December 2022, also recognizes that “climate change is a security issue that concerns the very existence of humankind.”

Such geopolitical risks and security implications of climate change have been discussed by the international community for more than a decade.

For example, since 2007, the United Nations Security Council has discussed the security implications of issues, such as climate change, resource and energy scarcity, water depletion, and ecosystem changes. The European Union, in its Common Foreign and Security Policy, also recognized that climate change, natural disasters, and environmental degradation have far-reaching effects on the resilience of communities and ecosystems on which life depends, and that these issues have led to numerous conflicts worldwide.

Government agencies and academic institutions, such as the University of Toronto in Canada, Stanford University in the US, Oslo International Peace Research Institute in Norway, Stockholm International Peace Research Institute in Sweden, and Nanyang Technological University in Singapore, have been actively pursuing climate security research.

In this regard, climate security was rarely discussed in Japan until the 2020s (1). For example, the National Defense White Paper first addressed the impact of climate change on the security environment and defense in 2021.

Thus, the geopolitical risks of climate change are highly important and cannot be neglected by Japan.

As described in recent peer-reviewed papers, climate change-induced environmental impacts, such as extreme weather events, natural disasters, and sea level rise, or countermeasures, such as decarbonization, energy transition, and geoengineering, are likely to lead to anti-government riots, ethnic conflicts, civil wars, and even inter-state clashes through a complex causal process (2, 3).

Particularly, countries that are highly dependent on agriculture, underdeveloped, or have poor governance are vulnerable to the impacts of climate change, and the risks of conflict and riots are correspondingly high.

However, Japan has a relatively high adaptive capacity to climate change and is free of conflict hotbeds, such as violent ethnic conflicts, within the country. Therefore, climate change-induced civil wars or large-scale anti-governmental riots in Japan are not generally anticipated.

Nevertheless, Japan may face climate security risks as mentioned below (4):

  • 1) Intensifying conflicts over territorial rights and exclusive economic zones in the surrounding seas
  • 2) Increased climate migration from Asia-Pacific countries
  • 3) Economic stagnation due to damaged supply chains and local markets in climate-vulnerable Asian neighboring countries

These climate security risks will emerge in the future, along with the increasing impact of climate change. Unfortunately, climate change has become a reality recently. According to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), which summarizes the latest scientific findings on climate change, global average temperatures have already risen by approximately 1.1 °C since the late 19th century; additionally, annual rainfall is increasing and the mean sea level rise is accelerating. Abnormal weather events, such as droughts, heat waves, and torrential rains, which have become increasingly severe worldwide in recent years, have also been reported to be related to climate change.

The effects of climate change are expected to become increasingly evident in the future. The world is striving to achieve carbon neutrality by 2050. Even if this goal is achieved, the IPCC report states that the global average temperature in mid-century (2041–2060) will be 1.2– 2.0 °C higher than in the late 19th century. If carbon neutrality is not achieved and greenhouse gas growth continues at current levels until mid-century, average temperatures are expected to rise in the range of 1.6–2.5 °C.

An increase in the average temperature of only 2 °C would increase the probability of an extreme heat wave by 13.9 times, which has occurred only once every 50 years in the late 19th century before climate change. Similarly, severe droughts, which occurred only once every 10 years in the 19th century, are expected to be 2.4 times more likely to occur when the average global temperatures would have increased by 2 °C .

Moreover, climate security risks become more realistic with the impacts of climate change. It is not a matter of today or tomorrow, but climate change can threaten social peace and stability in an amplified manner as a “threat multiplier.” When the wheels are in motion, they may become irreversible.

Thus, the key to risk management is preparing for the worst-case scenarios. Moreover, every individual company and government should be aware of the climate security risks to which they would be exposed to, and take the necessary steps to avoid them.



  1. 1. Odeyemi C, Sekiyama T. A Review of Climate Security Discussions in Japan. International Journal of Environmental Research and Public Health. 2022; 19(14):8253.
  2. 2. Sekiyama T. Climate Security and Its Implications for East Asia. Climate. 2022; 10(7):104.
  3. 3. Nagano T, Sekiyama T. Review of Vulnerability Factors Linking Climate Change and Conflict. Climate. 2023; 11(5):104.
  4. 4. Sekiyama T. Climate Security in East Asia and Potentials for Sino-Japanese Cooperation. Journal of the International Security Studies. 2022; 14:126-148.


(This is the English translation of an article written by SEKIYAMA Takashi, Associate Professor, Kyoto University, which originally appeared on the e-forum “Hyakka-Seiho (Hundred Flowers in Full Bloom)” of JFIR on May 29, 2023.)