The climate crisis demands One Health revolution

The One Health approach has moved from the margins of global health into the mainstream as climate change reshapes the conditions in which people, animals, and ecosystems coexist. 

Rising temperatures, environmental degradation, and accelerating urbanization are no longer distant risks but active forces shaping public health outcomes today.

In 2024, global temperatures exceeded 1.5 degrees Celsius above pre industrial levels across a full calendar year, marking a historic climate threshold. This warming is not abstract. It is driving heat stress, water insecurity, air pollution, and ecological disruption that increasingly converge in the places where people live and work.

One Health helps explain why these pressures cannot be addressed in isolation highlighting the interconnectedness and interdependence of animal health, environment health and human health: extreme heat affects food systems and labour productivity; water scarcity alters sanitation and disease exposure; ecosystem degradation weakens natural regulation of pathogens, while biodiversity loss destabilizes the balance between humans, animals, and the environment.

These dynamics are already visible in disease patterns. Around 60 percent of emerging infectious diseases originate in animals, and more than 75 percent of newly identified human pathogens in recent decades have zoonotic origins. Climate change and land use pressures are accelerating these spillover pathways.

Biodiversity loss further compounds the risk. Global wildlife populations have declined by an average of about 73 percent since 1970, eroding ecosystems that regulate water quality, buffer climate extremes, and reduce disease transmission. This ecological decline directly undermines human and animal health resilience.

Despite this reality, One Health often remains framed as a coordination exercise rather than a delivery system. Many national strategies emphasize collaboration and data sharing but struggle to convert integrated thinking into preventive action where exposure actually occurs.

The profession of environmental health lies at the point where these three areas of health overlap. For decades, it has governed the practical interfaces where climate, environment, animals, and people intersect through food safety, water and sanitation, waste management, vector control, housing standards, and pollution control.

These functions reduce climate sensitive health risks while advancing environmental sustainability. Safe water systems protect communities during droughts and floods. Food safety regulation limits heat driven contamination. Vector control curbs the spread of climate sensitive diseases.

Environmental health also turns nature-based solutions into public health assets. Mangrove restoration, wetland protection, urban greening, and sustainable land management enhance biodiversity, lower temperatures, improve air quality, and strengthen resilience while reducing long term health system burdens.

As Graeme Mitchell, award-winning environmental health educator at Liverpool John Moores University, notes: “Environmental health is where One Health becomes real. It is the point where climate science, biodiversity protection, and public health stop being abstract goals and start shaping safer livelihoods, cleaner water, and healthier lives for generations to come.”

Seeing environmental health as central to One Health aligns ambition with practice. One Health defines the interconnected challenge space shaped by climate change and decarbonization, while environmental health delivers the regulatory and preventive tools that reduce exposure and build resilience on the ground.

Saudi Arabia is well positioned to lead this transition. Vision 2030 reforms and environmental governance modernization provide the institutional foundation to translate integrated health thinking into measurable outcomes in a changing climate.

The Kingdom faces climate driven risks including extreme heat in a region warming faster than the global average, severe water scarcity, food system vulnerability, and rapid urban growth. At the same time, investments under initiatives such as the Saudi Green Initiative, alongside clean energy expansion and biodiversity protection, create opportunities for integrated prevention.

Embedding One Health through environmental health allows climate adaptation and sustainability to become part of everyday governance. This strengthens accountability and ensures environmental aspirations translate into advanced protection for people, animals, and ecosystems.

Four strategic actions can position Saudi Arabia as a global leader in climate aligned One Health delivery.

First, place environmental health at the center of national One Health governance to anchor coordination in operational authority and regulatory action across all sectors.

Second, integrate One Health principles into food safety, water quality, vector control, and environmental regulation to embed climate adaptation frameworks into business practice.

Third, strengthen the environmental health workforce through tailored training, digital tools, and institutional recognition to manage climate driven risks proactively.

Fourth, link environmental, animal, and human health data into unified digital surveillance systems to support early warning, biodiversity protection, and evidence-based decision making.

By placing environmental health at the core of One Health, Saudi Arabia can move from integrated ambition to integrated delivery, strengthening public health resilience amid accelerating climate impacts and offering a model that international institutions can follow.

• Hassan Alzain is the author of the award-winning book “Green Gambit.”