Japanese Prime Minister Fumio Kishida’s visit to Washington on January 13, 2023 highlighted the importance of the U.S.-Japan alliance as the cornerstone of a free and open Indo-Pacific region. It also underscored how Japan’s changing security posture and to its own defense capabilities contribute so vitally to regional deterrence.[1] During the visit, Prime Minister Kishida and President Biden also reaffirmed the importance of cooperation on global issues, such as climate change and energy security.[2] The predominance of these two issues in the discussions speaks to how intertwined they are in the region. If U.S-Japan strategic cooperation is essentially shaped by the mutual need to deter any potential Chinese aggression in the Indo-Pacific, the overall context in which this relationship occurs is shaped by the changing climate in the region. Instabilities wrought by climate change now fundamentally reshape the security construct for the US Japanese security partnership.

Both Japan and the U.S. acknowledge the interconnection between climate change and security in the Indo-Pacific, as well as the importance of cooperation to address shared challenges. The U.S. National Security Strategy (NSS) released in October 2022 reaffirmed the importance of partnering with Indo-Pacific allies to “support a rules-based international system” in the face of China’s “assertive behavior”, as China retains “common interests with other countries because of various interdependencies on climate (...)”. The document also points to the Indo-Pacific as being “the epicenter of the climate crisis” but also “essential to climate solutions.” Japan’s National Security Strategy (NSS), published two months later in December 2022, extensively covers the climate-security nexus from its first paragraph, stating that “a host of issues such as climate change (...) are emerging, requiring cross-border cooperation among nations” as they impact “Japan's national security in various ways.”

From forest fires to heatwaves and droughts in Tokyo[3], from floods in Kyushu to rising sea levels and violent typhoons,[4] Japan faces multiple threats from climate change with impacts on its ecosystems, human health, livelihoods, and across key economic sectors such as fisheries.[5] In addition to domestic climate risks, Japan also has to deal with a changing regional security context where climate change amplifies tensions with neighbors and increases competition over shared resources and maritime borders -for instance, Japan has been facing incursions from Chinese fishing vessels into its Senkaku territorial waters.[6] This is particularly the case in the South China Sea, increasingly militarized by China, where Japan has strategic interests that include ensuring open sea lines of communication for its international trade and energy imports.[7]

In this context, climate-security cooperation between Japan and allies like the U.S. is essential and is two-fold: leading the way on decarbonization and technology innovation, and assisting the most vulnerable countries of the region in adapting to climate change and mitigating their own climate risks.

Japan’s NSS 2022 states that “Japan will lead the way (...) with all stakeholders, including its ally and like-minded countries (...) toward the realization of a decarbonized society”, while the U.S. Indo-Pacific Strategy released in February 2022 highlights the U.S. ambition to be seen as the preferred partner for incentivizing clean-energy investments in the region.[8] At the bilateral visit in January, both countries agreed to boost their cooperation on nuclear energy -already existing under the Clean Energy and Energy Security Initiative- to develop next-generation light-water reactors and small modular reactors[9]. These efforts to advance nuclear solutions that are safer than conventional reactors may help Japan overcome its major distrust toward nuclear energy following the Fukushima disaster in 2011, and eventually enhance domestic nuclear energy production. The latter would ultimately allow Japan to free itself from its current reliance on energy imports as well as from its dependency on fossil fuels, including coal, whose production surged following the decommissioning of most of Japan’s nuclear plants.[10] Offshore wind, geothermal and grid integration are other areas where cooperation should be strengthened to overcome existing challenges such as technical barriers, sourcing and manufacturing. Finally, Japan’s leadership in hydrogen supply chains provides a comparative advantage in this important sector of the clean energy transition. To advance Japan’s decarbonization efforts, Japanese trading companies are already exploring ways to convert U.S. hydrogen into ammonia to use it as fuel.[11]

Additionally, Japan’s NSS 2022 mentions that “Japan will provide assistance to island nations and other developing countries where climate change poses imminent threats so that sustainable and resilient economies and societies can be built.”. Neighboring nations like Pacific Island Countries, Vietnam, Cambodia, the Philippines and Papua New Guinea are as threatened by China’s regional assertiveness and ambitions as they are vulnerable to climate risks. For most of them, reliance on Chinese investments has also contributed to increased vulnerability. Assistance to regional countries to enhance climate and economic resiliency is a key aspect of the U.S-Japan bilateral cooperation. One possible avenue to strengthen these efforts could be for the U.S. to engage, through financial, technical and technological assistance, in Japan’s Asia-Pacific Climate Change Adaptation Information Platform (AP-Plat) launched by Japan’s Ministry of Environment in 2019 to provide Asia-Pacific countries with data on climate effects and to support climate-informed policies and effective climate adaptation in the region.[12]

Ultimately, beyond mere bilateral cooperation, other frameworks like the QUAD are excellent platforms to strengthen joint efforts on climate security. The QUAD, which involves Japan, the U.S, India and Australia, benefits from an impetus on climate affairs since Australia’s new Labour government has committed to bolster its own climate ambitions. Practical cooperation on climate change was extensively discussed at the QUAD Leaders’ Summit in Tokyo in May 2022, where the QUAD countries established a climate working group to cut emissions in the Indo-Pacific via clean energy and infrastructure and resilient supply chains, and to help neighboring countries prepare and adapt.[13]

While joining forces on climate mitigation and assistance will help Japan achieve its climate objectives and ensure its own energy security and stability, it will also allow Japan and the U.S. to be leaders in the energy transition and to participate in a free, open and more secure Indo-Pacific region.