Climate change is more than an environmental crisis, it’s a public health emergency. Rising global temperatures, changing rainfall patterns and increasing climate variability are dramatically altering the habitats and behaviors of disease-carrying vectors such as mosquitoes, ticks and flies. Vector-borne diseases, caused by parasites, bacteria or viruses, now account for more than 17 percent of all infectious diseases, resulting in over 700,000 deaths each year. Malaria alone is responsible for more than 600,000 of these deaths. The growing threat is amplifying the risks of diseases such as dengue, chikungunya and Japanese encephalitis, especially in regions already facing climate stress, rapid urbanization and weak health infrastructure.

The science is clear. Warmer climates extend the breeding seasons and geographical range of many vectors, while increased rainfall or poor water management in urban settings provides ideal conditions for their spread. Take the case of Tehran Province in Iran, a semi-arid region now facing a surge in mosquito habitats due to a 7.3 percent rise in average temperatures and declining rainfall, conditions exacerbated by rapid urban growth. Similar trends are playing out across Asia, with countries like Bangladesh, Viet Nam and Thailand seeing record numbers of dengue cases in 2023.

This is not just a tropical issue. Vectors are adapting to cooler temperatures and higher altitudes, making outbreaks more likely in regions previously considered low-risk. Climate change is reshaping the very map of disease.

Compounding this threat are overlapping risk factors, including urban density, deforestation, weak surveillance, migration, low community awareness and overstretched health systems. Post-pandemic fatigue has left many communities and frontline workers vulnerable, while misinformation and delayed responses continue to undermine outbreak control.

UNDP, with its long-standing presence at the intersection of climate action, governance and health systems strengthening, is uniquely positioned to support countries in addressing this threat. We work with governments, civil society and global partners to promote inclusive policy reform, strengthen community resilience and leverage digital and data innovations that shift responses from reactive to anticipatory. Through our Health Systems Strengthening portfolio and new private sector collaborations, we are helping countries turn risk into readiness.

Across Asia-Pacific, UNDP is supporting countries to strengthen early warning systems, climate-proof health infrastructure and enhance local capacity to anticipate and manage outbreaks.

Together with WHO, UNDP has helped six countries launch a regional programme to integrate climate risks into health planning and surveillance, tailored to national vulnerabilities. For example, Cambodia developed new dengue surveillance protocols and trained over 120 frontline health workers on climate-informed outbreak monitoring, while Lao PDR and Bangladesh launched early warning systems that link weather and health data to forecast climate-sensitive disease outbreaks.

Similarly, in Viet Nam, UNDP supported the development of an Integrated Early Warning System for dengue that predicts outbreaks up to four weeks in advance, combining predictive tools with community engagement and intersectoral coordination to strengthen local response capacities.

Beyond vector-borne diseases, our broader climate–health efforts, from equipping remote clinics with solar power for reliable, low-carbon energy to improving healthcare waste management in climate-vulnerable communities, are reinforcing community resilience to a wide range of climate-driven health threats. Reliable energy access is also central to this effort as one in four health facilities worldwide still lacks electricity, leaving nearly a billion people reliant on care that is inconsistent or unsafe.  

Despite growing urgency, investments in surveillance, vector control and entomological research remain dangerously inadequate. Innovations in vector tracking and predictive analytics exist but lack scale and coordination. Most global strategies are still reactive, siloed and disconnected from the communities most at risk.

It’s time for a paradigm shift.

We need a coordinated, forward-looking and community-driven response that can keep pace with the accelerating risks. This requires:

• Integrated surveillance and early warning systems that connect climate and health data, local knowledge, and mobility trends to identify outbreaks before they explode that connect climate and health data, local knowledge, and mobility trends to identify outbreaks before they explode.
• Investments in innovation and applied research, from AI-powered forecasting to climate-adaptive vector control tools, coupled with operational studies to ensure solutions work in real-world settings.
• Stronger community engagement and trust-building, where health and climate resilience go hand in hand, with people empowered to reduce risks through behavior change, timely information, and access to services.
• Cross-border and multisectoral collaboration that reflects the interconnected nature of climate, ecosystems, and health threats.

The time between the emergence of a new pathogen and a widespread outbreak is shrinking. We must act now, not just to respond to the diseases of today, but to prepare for those of tomorrow. A climate-smart, equity-driven, and prevention-first approach to vector-borne diseases must be part of any serious strategy for global health security.