A few months ago, Typhoon Yagi swept across numerous countries in East and Southeast Asia, leaving a path of destruction from extreme winds and floods. As countries implement extensive response and recovery efforts, this event underscores the importance of regional cooperation and preparedness in the face of disasters.

The region comprising the Association of Southeast Asian Nations, or ASEAN, has long been considered one of the most disaster-prone parts of the world. According to a World Meteorological Organization report published in April, Asia remained the world’s most disaster-hit region from weather, climate and water-related hazards in 2023. Floods and storms caused the highest number of reported casualties and economic losses, while the impact of heatwaves became more severe.

Climate change-induced disasters pose an increasingly serious threat to Asia and the Pacific. The region remains the most disaster-prone region in the world where 2 million people have lost their lives to disasters since 1970. In 2022, over 140 disasters struck the Asia-Pacific region, leading to over 7,500 deaths, affecting over 64 million people and causing economic damage estimated at US$ 57 billion, said the UN Economic and Social Commission for Asia and the Pacific (ESCAP) reportSeizing the Moment: Targeting the Transformative Disaster Risk Resilience.

Given the region’s high exposure to extreme events, a study by the Asian Disaster Preparedness Center’s (ADPC) and the Earth Observatory of Singapore (EOS) entitled "Transboundary Disaster Risk Assessment and Scenario Planning for Tropical Cyclones and Droughts in the ASEAN Region" was developed to help decision-makers understand the degree of severity of the potential impacts of transboundary tropical cyclones and regional drought and help to identify appropriate risk management strategies for these prioritized disaster risks.

The study reaffirms that recent tropical cyclones such as Typhoon Yagi and the El Niño led droughts in 2023-2024 have far-reaching consequences within and across national borders. Tropical cyclones cause destruction from violent winds, flooding and landslides, displacing communities and leading to significant loss of life and property. Similarly, droughts affect agricultural production, raising food security concerns and exacerbating health risks and economic downturns.

The report also focused on the transboundary implications of disasters. Tropical cyclones for instance, can impact numerous countries simultaneously, as was the case for the Sept 2024 Typhoon Yagi which impacted the Philippines, Hong Kong, South China, Vietnam, Laos, Thailand and Myanmar. Droughts, too, can have direct impact at a regional scale, and lead to cascading impacts at the global scale. The disruption in agriculture production in countries such as Thailand or Vietnam, which are considered major commodity exporters, can have far-reaching impacts on the countries that depend on food imported from those two countries. Such transboundary catastrophes pose particular challenges for response across national jurisdictions, highlighting the importance for regional coordination mechanisms like the ASEAN Coordinating Centre for Humanitarian Assistance on Disaster Management (AHA Centre). Such coordination will be even more critical as climate change is likely to increase the rate and intensity of these events.

Projected drought occurrence probability (%) during dry season.

Projected impacts of future cyclones and droughts

The study focused on future impacts of cyclones and droughts in Cambodia, Philippines, and Vietnam – all ASEAN Member States. The ADPC-EOS teams used climate change models to demonstrate the current and future expected impacts of these events and inform the ASEAN Member States how to address them effectively. Based on four different climate projection models, the study indicates that the frequency and intensity of tropical cyclones and droughts in Southeast Asia are expected to increase in the future.

The study found for instance that transboundary tropical cyclones in Southeast Asia could damage many more homes in the future unless they are protected. The number of homes damaged by tropical cyclones could increase by 30 to 60% on average across the three study countries by 2050, though the increase varies across countries. While absolute risk will remain greatest in the Philippines, the most significant climate-change driven increase in tropical cyclone risk will occur in northeastern and central eastern Vietnam, including the metropolitan area of Hanoi, one of the global manufacturing hubs. Home to approximately 20 million people, Hanoi also serves as a political and economic center of Viet Nam. The other economic hub, Ho Chi Minh City, is also at considerable risk.

Average annual impacts of tropical cyclones based on historical (1980-2018) climate conditions.

Increased drought risk could impact crop production in Cambodia, the Philippines and Vietnam. Among the three focus countries, it appears that Cambodia is most likely to be hit hardest by future drought and in a worst-case scenario, will see a 46 percent increased probability of drought in the dry season by 2080. In Vietnam, 63 percent of the country’s rice paddy field area could be affected by severe drought.

"This study showcases the need for collaboration on transboundary disaster risk management in the ASEAN region," Pham Duc Luan, Chair of the ASEAN Committee on Disaster Management and Director-General of Vietnam Disaster and Dike Management Authority, Ministry of Agriculture and Rural Development, said in the report.

"Disasters do not recognize borders! The collaboration of ASEAN Member States in disaster preparedness will ultimately contribute to greater regional stability and resilience," said Peeranan Towashiraporn, Director of Risk Analytics and Climate Services at ADPC and lead of the project.

Visual representation of the expected annual monetary losses due to tropical cyclones in each country, based on historical climate conditions.

Summary of the key findings of the study.

How can ASEAN states prepare for the future increase in cyclone and drought risks?

Based on these findings, the study provides recommendations for the ASEAN Member States to enhance disaster risk management actions, in line with the ASEAN Agreement on Disaster Management and Emergency (AADMER) Work Programme 2021-2025.

The study directly contributes to the implementation of Priorities 1 and 2 of the AADMER Work Programme. Priority Programme 1, on Risk Assessment and Monitoring, benefits directly from the transboundary risk assessment methodology used in this study. Priority Programme 2, on Prevention and Mitigation, can utilize the resulting hazard, vulnerability, and risk information for disaster risk reduction and climate change adaptation planning, as well as planning for long-term resilient development.

The recommendations also emphasize the importance of gender equality and social inclusion for effective disaster risk management. Women and men, children and the elderly, as well as persons with disabilities (PWD), experience, perceive, and are affected by disaster risks differently. Hence, investing in gender-sensitive and socially-inclusive disaster risk management and resilience-building will help achieve the goals of Priority 2 of AADMER Work Programme, and is critical for the achievement of the Sustainable Development Goals and the Sendai Framework for Disaster Risk Reduction by 2030.

"Climate and disaster risks are all-of-society problems that demand all-of-society responses. To forge a resilient future, scientists and policymakers must work together to understand shared risks and craft resilience programs that respond to the vulnerabilities and capacities of diverse communities" say Dr. David Lallemant, Associate Professor at NTU and an author of the report.

Summary of the priority recommendations based on the findings of the study.

This study is a call to action for planning a safer and more resilient ASEAN region. Collaboratively implementing these recommendations could help ASEAN Member States save lives and secure the region's future prosperity.

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