Climate Change as a Health Security Threat in Pakistan: Preparing Health Systems for Extreme Events.

Pakistan is confronting the climate crisis as an immediate and systemic threat to national health security rather than an environmental concern. Recurrent floods between 2022 and 2025 affected more than 26 million people, damaged health infrastructure, disrupted essential services, and placed the country at the top of the Germanwatch Climate Risk Index. These shocks have intensified pre-existing health system fragilities by driving surges in malaria, waterborne infections, malnutrition, antimicrobial resistance, and forced displacement, while constraining routine service delivery. Climate-related migration to peri-urban informal settlements has created new epidemiological vulnerabilities characterized by overcrowding, poor sanitation, and outbreaks such as extensively drug-resistant typhoid. Simultaneously, crop losses and food system disruption have worsened child undernutrition in districts already exceeding emergency thresholds, with women and children disproportionately affected because of structural barriers to maternal, neonatal, and immunization services. Climate variability is also increasing the risk of zoonotic spillover and undermining progress toward Universal Health Coverage. We argue that climate change functions as a threat multiplier for Pakistan's health security and must be systematically integrated into health policy and planning. Key priorities include climate-resilient health infrastructure, strengthened integrated surveillance using digital and geospatial tools, prevention-oriented primary care, and operationalization of a One Health framework. Effective intersectoral governance, provincial implementation, and sustained collaboration with international partners, including the World Health Organization, are essential for building a resilient health system capable of maintaining continuity of care during increasingly frequent climate shocks.