1. Climate Change and the Current Status and Outlook of Refugees and Displaced Persons Worldwide

The number of refugees and displaced persons is increasing globally. According to the United Nations High Commissioner for Refugees (UNHCR), 117.3 million people were forcibly displaced in 2023 due to conflict, persecution, and other causes. This means that a number of people nearly equivalent to Japan’s population have been forced to flee their homes around the world.　In addition to “refugees,” who are forced to cross international borders, there are also “internally displaced persons” (IDPs), who are compelled to flee within their own countries. According to the 2024 report by the Internal Displacement Monitoring Centre (IDMC), the number of IDPs globally has reached 75.9 million. Nearly 47 million people were newly displaced or forced to move in 2023 alone. Of these, 20.5 million were displaced due to conflict or violence, while 26.4 million, representing 56 percent of the total, were displaced by disasters such as major earthquakes and cyclones. A notable recent trend is the increase in disaster-related displacement even in high-income countries. For example, in Canada in 2023, unprecedented wildfires forced 185,000 people into internal displacement. A 2009 projection by the International Organization for Migration (IOM) estimated that environmental changes would compel 200 million people to migrate by 2050. In reality, the pace of displacement appears to be exceeding even that forecast.

In response to these developments, the World Bank published Part I of its report Groundswell: Preparing for Internal Climate Migration in 2018, followed by Part II in 2021. The report highlights internal displacement and migration driven by environmental factors, an area that had traditionally received limited attention, and presents projections for the future increase in internally displaced persons. According to the report, if proactive climate change mitigation and development policies are not implemented, as many as 216 million people around the world could be forced to move within their countries by 2050 due to factors such as water scarcity, declining agricultural productivity, sea-level rise, heat stress, and extreme weather events. It is also pointed out generally that migration will not necessarily occur suddenly or uniformly. Rather, it will follow a variety of patterns and coping mechanisms, such as people temporarily migrating to urban areas during periods when crops cannot be harvested. These diverse forms of mobility indicate that migration and displacement are not monolithic in nature.

While the importance of climate change mitigation through greenhouse gas reduction is undeniable, the need for adaptation measures is becoming increasingly urgent. Even if countries fulfill their current “Nationally Determined Contributions (NDCs)”, it is unlikely that global warming will be limited to within 1.5 degrees Celsius. The Intergovernmental Panel on Climate Change (IPCC) classifies the impacts of climate change on migration into four categories. The first is “adaptive migration,” where individuals or households choose to move. The second is “involuntary or forced migration,” where there are few alternatives to relocation. The third involves “planned relocation from areas with high climate risk.” The final category refers to situations where movement is not possible, due to cultural, economic, or social constraints, leaving people unable or unwilling to flee high-risk areas. Observations around the world indicate that those who are socially most vulnerable or lack the necessary resources are often the ones who remain behind, unable to evacuate or relocate when climate risks intensify.

It is worth noting that the 1951 Convention Relating to the Status of Refugees defines a refugee as someone who has fled their country “owing to a well-founded fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group, or political opinion.” Under international law, so-called “climate refugees” or “environmental refugees” have generally not been recognized as refugees in the legal sense. The Convention protects individuals who are at risk of persecution in their home country due to factors such as race, religion, or political beliefs and who have sought refuge abroad. In contrast, the gradual nature of climate change often leads to it receiving less attention as a driver of displacement. However, in 2020, the UNHCR published a document titled Legal Considerations Regarding Claims for International Protection Made in the Context of the Adverse Effects of Climate Change and Disasters[1]. This document presented a new perspective, stating that individuals affected by climate change and disasters may be entitled to claim refugee status under the existing framework of international law. The implementation and interpretation of this position will be important to pay due attention in the coming years.

2. The Relationship Between Climate-Induced Migration and the Risk of Conflict

Does climate-induced migration have any impact on peace and security? A joint study conducted by the Norwegian Institute of International Affairs (NUPI) and the Stockholm International Peace Research Institute (SIPRI) offers interesting andcompelling analysis of this question. The study identifies four primary pathways through which such effects can emerge. First, extreme weather events and natural disasters can destroy livelihoods and undermine the foundations of daily life, leading to social destabilization. Second, large-scale migration or population movement can intensify competition for resources and employment between host communities and incoming refugees or displaced persons, potentially exacerbating existing tensions. Third, military forces and armed groups may exploit environmental changes caused by extreme weather to expand their power, for example by securing new sources of revenue or recruiting personnel. Fourth, political and economic exploitation can take root in unstable conditions, further deepening insecurity. In an interview with Professor Cedric de Coning of NUPI, who led the study, he noted that these are not necessarily typical pathways but rather should be seen as extreme cases, some of which have drawn attention at the United Nations.

The Uppsala Conflict Data Program (UCDP) at the Department of Peace and Conflict Research, Uppsala University in Sweden, defines armed conflict as involving “at least 25 battle-related deaths per year” and “at least one party being the government of a state.” UCDP collects and publishes global data on such conflicts. However, it is important to note that conflict does not always manifest as violence. It can emerge in various aspects of social life, especially when differences in ideology, goals, or values are involved. The existence of conflict itself is not inherently negative. However, when destructive methods are used to resolve conflict, serious harms can result. Mechanisms of conflict resolution include legal proceedings, debate, and voting, among others. Yet, if structural violence remains unaddressed, achieving genuine peace becomes difficult. In the context of climate change, when natural resources that form the basis of livelihoods are damaged or their distribution is altered, structural inequalities and injustices may deepen. This, in turn, raises concerns about an increased risk of conflict within the society.

3. Case Studies from the Asia Region

A study was conducted by Associate Professor Tobias Ide of Murdoch University in Australia on how disasters shape the dynamics of armed conflict, analyzing 36 case studies from countries in Asia[2]. The findings categorize the impacts of disasters on conflict into three types: “no significant impact” (18 cases), “exacerbated conflict” (9 cases), and “alleviated conflict” (9 cases). The nature of these outcomes was found to be heavily influenced by the motivations of group leaders and members. When grievances existed prior to a disaster, conflict tended to intensify. On the other hand, disasters could also foster social cohesion among affected populations. In some cases, armed groups exploited these grievances to recruit youth, while in others, the disaster disrupted the activities of such groups. One example where a disaster had little impact on conflict is Typhoon Haiyan, which struck the Philippines in 2013. A case where conflict worsened was the 1998 flood in Assam, India, where armed groups reportedly used the disaster as an opportunity for recruitment. An example of conflict being alleviated is Cyclone Sidr, which struck Bangladesh in 2007. In this case, weakened leadership among armed factions and declining public support for them contributed to a reduction in conflict. The study further notes several factors that make conflict more likely to arise in the aftermath of a disaster. These include high dependence on agriculture, the absence of democratic political systems, and high levels of poverty.

In addition, a 1996 study by Swain[3] examined the impact of environmental change in the context of the Farakka Barrage in India. Since the Green Revolution of the 1960s, water extraction from the Ganges River has increased significantly in the upstream areas of India due to population growth. As a result, people living in the southwestern part of downstream Bangladesh have suffered from severe water shortages. This led to saltwater intrusion, a decline in mangrove forests, and large-scale population outflows, with tens of thousands migrating to Assam and Delhi in India. One particularly serious consequence was the violence in Assam in 1983, where incoming Bangladeshi Muslim migrants faced violent attacks from local Indian Hindus. According to reports, 1,700 people lost their lives, and the total death toll from both sides reached approximately 3,000. While this case cannot be classified as climate-induced migration per se, it demonstrates how large-scale population movements triggered by environmental changes can have severe regional impacts.

4. Conclusion and Outlook

In conclusion, and drawing on the discussions held in the 2024 research group organized by the Japan Forum on International Relations (JFIR) titled “Establishing a Framework for Assessing Social Risks of Conflict Indirectly Caused by Climate Change,” this section offers a forward-looking perspective. A review of existing studies reveals that there are relatively few cases in which a direct causal relationship has been established between weather-related disasters, the resulting generation of migrants or refugees, and subsequent conflict. However, a recurring theme underlying the four conflict pathways identified by SIPRI and NUPI is the loss of livelihoods among displaced populations. In response, various emergency, humanitarian, and development assistance programs have been implemented to protect the livelihoods of both displaced people and host communities. Going forward, expanded support and more preventive measures will be essential. One of the key insights from Professor Ide’s research is that the degree of vulnerability among conflict actors and society plays a decisive role in determining whether a disaster will escalate or de-escalate conflict. As research on climate change and migration advances, several emerging issues warrant closer attention. These include securing the legitimacy of using climate finance to support emergency displacement and planned relocation, ensuring that migration as a form of climate adaptation does not lead to new forms of conflict or tension, and exploring how post-disaster recovery assistance can be designed to mitigate conflict risks.

In addition to existing research on the economic losses associated with short-term displacement, there is an increasing need to strengthen studies on preventive measures and urban planning to address long-term impacts. For instance, in Japan, more detailed analyses are required to assess how coastal areas may be affected by future sea-level rise. Until now, a significant portion of research funding has been allocated to short-term disasters such as typhoons. In particular, in developing countries, support for planned relocation remains limited, with such moves often carried out primarily through self-help. Strengthening assistance for involuntary relocations, as well as support to ensure economic stability and livelihoods after relocation, is an area where research on climate change and migration can provide valuable insights. It has also been noted that host communities receiving migrants often receive little assistance. Tensions may arise between relocated individuals and host populations due to disparities in aid, making long-term, forward-looking research and practice all the more critical. These efforts are especially important to ensure that people who have not been adequately protected under existing legal frameworks can receive the support they need.

Furthermore, there is a lack of research that considers the temporal dimension of displacement. Specifically, it remains unclear to what extent long-term disasters such as sea-level rise have contributed to increases in the number of migrants and refugees. While short-term disasters more readily lead to displacement, many of those affected often return to their original homes. As a result, host communities tend to be more receptive, and such situations are less likely to lead to conflict. On the other hand, those displaced by prolonged drought or rising sea levels are often unable to return and tend to remain in the receiving areas, which can increase the risk of tensions. However, this point still requires further empirical research. Notably, Professor Ide’s study previously mentioned found no significant relationship between the duration of a disaster and the likelihood or form of conflict.

One example of large-scale migration in Europe linked to climate-related conflict, as introduced by members of the research group, is the displacement of an estimated 13 million refugees and internally displaced persons from Syria in the mid-2010s, some of whom were accepted by European countries. Sweden, a long-standing destination for migrants, began accepting migrants as early as the 1960s during the Vietnam War and has historically received large numbers from regions such as the Middle East and Eastern Europe. While Sweden has been known for its inclusive and tolerant immigration policies that emphasize diversity, recent years have seen signs of social instability within host communities. Following Russia’s invasion of Ukraine, Sweden shifted to a center-right government in 2022, and its policies have since moved toward restricting immigration. At the same time, Sweden is also engaged in international cooperation aimed at strengthening “adaptation measures” as a form of preventive strategy to avoid the large-scale displacement of people in the first place. It can be said that the heightened awareness of climate issues in Europe is in part driven by the influx of migrants.
In contrast, in New Zealand, the Minister for Climate Change announced in 2017 that the government was considering issuing an “experimental humanitarian visa” for Pacific Islanders who had been forced to flee due to climate impacts. However, the plan was withdrawn six months later. One reason for this reversal was criticism from the Pacific Island nations themselves, who urged instead for enhanced adaptation support within their own countries. The author recalls a discussion with leaders from the Pacific Islands, who expressed that they “do not want to be treated as refugees.” More broadly, in recent years, many developed countries have seen a political shift toward conservatism and right-leaning governments, accompanied by increasingly restrictive immigration policies and tighter border controls. Against this backdrop, there is a risk that linking migration too simplistically to security concerns could fuel narratives that portray displaced people as threats to host societies. Such framing may reinforce harmful prejudices and obstruct calm, evidence-based discussion on migration issues.

Initial conditions vary by country and region, and as a result, societal responses to disasters differ significantly. Given the characteristics of the Asia-Pacific region, it is important to analyze both short-term and medium- to long-term timeframes. Additionally, mapping socially vulnerable areas alongside regions with high climate risk is essential for identifying future high-risk zones. Developing plans to strengthen resilience and investing in infrastructure are also critical measures. While disaster response requires attention to local context, countries in the Asia-Pacific region share many commonalities, making mutual learning and technical cooperation both possible and desirable. As economic growth continues in the region, funding sources are becoming more diverse. It is therefore increasingly important to consider the intersection of climate change and human mobility, and to focus on the potential opportunities this presents.

(This is an English translation of a commentary by MAEKAWA Miko, Senior Research Fellow at the Sasakawa Peace Foundation and Visiting Professor at the International Research Institute of Disaster Science (IRIDeS), Tohoku University. The original Japanese version was published on the JFIR website on March 31, 2025. )