As part of our blog series responding to the National Emergency Briefing on Climate and Nature, we are exploring each of its key themes between now and the end of January. The briefing makes clear that responding to the climate and nature emergency requires rapid, coordinated action across many siloes, and we’re here to show you how it can be done.

The National Emergency Briefing sets out a clear reality: the UK is now operating in a permanently changed risk environment. Extreme weather is no longer an occasional disruption. It is a structural threat to health, public services, infrastructure and social stability.

This assessment is now reinforced at the highest levels of government. The UK Government’s National Security Assessment on Global Biodiversity Loss, Ecosystem Collapse and National Security makes it explicit that environmental breakdown, including climate extremes and ecosystem degradation, constitutes a direct national security risk, with cascading effects on food systems, economic stability, public health and social cohesion.

In July 2022, the UK recorded 40°C for the first time. Hospitals declared critical incidents, ambulance services struggled to meet demand, and England experienced over 3,000 excess deaths in a single heatwave period, largely from cardiovascular and respiratory causes. Since then, winter storms have flooded homes, cut power to care‑dependent residents, and forced GP surgeries and pharmacies to close at short notice. Air pollution continues to contribute to an estimated 28,000–36,000 premature deaths each year, with the highest burden falling on more deprived communities. 

These are no longer exceptional events. They are becoming part of everyday life. 

The National Emergency Briefing frames this not as a narrow environmental issue, but as a national resilience challenge that cuts across health, housing, energy, food, transport, digital infrastructure and local government. Health is where these risks ultimately surface. This is exactly the type of challenge OnePlanet is designed to address.

Through its work with Impact on Urban Health, OnePlanet supported the organisation to understand how climate risk affects every programme area — from physical activity and food access to housing, air quality and mental health. Rather than treating climate as a standalone theme, OnePlanet was used to map how environmental risk amplifies existing health inequalities and shapes outcomes across the whole portfolio.

Heat exposure, air pollution, flood risk, access to green space and the resilience of neighbourhood infrastructure were analysed alongside population health data and community need. This systems view made it possible to see where climate risk was already undermining health outcomes, identify communities facing overlapping environmental and social vulnerability, and design interventions capable of delivering multiple benefits at once. Crucially, OnePlanet provided a shared planning tool that allowed teams to work across traditional programme boundaries, so climate, health and community development could be planned as a single, connected system rather than as parallel strands of work.

Alongside strategic planning, OnePlanet was also used to build resilience from the ground up by empowering community organisations. Local groups were supported to understand how their work contributes to wider climate and health outcomes, connect with each other around shared priorities, and plan collaboratively rather than compete for isolated funding. This bottom‑up capability is essential: extreme weather impacts are felt first and most acutely at community level — by older people living alone during heatwaves, families in flood‑prone housing, children exposed to polluted air, and residents dependent on local services during storms and power disruption.

Extreme weather is now a core determinant of health. Heatwaves drive sharp increases in cardiovascular and respiratory mortality, flooding disrupts access to medicines, primary care and social care, air pollution worsens asthma, COPD and pregnancy outcomes, and storms and power disruption affect digital health systems and emergency response. The NHS already plans for climate‑related surges in emergency demand. A stark indicator of how rapidly this risk is changing is the insurance market: premiums are rising, excesses are increasing, and cover is being withdrawn altogether in high‑risk flood and heat‑exposed areas. Climate risk is already being priced into the built environment and household security. 

These risks are not confined to UK borders. The national security assessment is clear that environmental shocks abroad — including droughts, floods and ecosystem collapse — pose direct risks to UK stability through global supply chains. Extreme weather affecting food‑producing regions overseas is already translating into higher prices, supply volatility and reduced nutritional access in the UK. For lower‑income households, this means increased food insecurity, poorer diet quality and higher risk of diet‑related disease. Climate shocks thousands of miles away are now felt on British supermarket shelves — and in British clinics.

What makes extreme weather so dangerous is not just the hazard itself, but the way it cascades across multiple systems at once. A heatwave is not only a health issue. It is also a housing issue, an energy issue, a transport issue, a digital infrastructure issue and a community resilience issue. Flooding is not only an emergency response issue. It is also a primary care issue, a pharmacy supply chain issue, a social care continuity issue and a mental health issue.

The National Emergency Briefing highlights that the UK’s current institutional model is poorly suited to managing systemic risk. Our systems remain organised around departmental boundaries, while climate and ecological risk cut across all of them. OnePlanet addresses this challenge by providing a shared, systems‑level operating picture — linking data, decision‑making and delivery so health, housing, transport, energy and emergency services can plan together, act early, and coordinate responses rather than working in isolation.

In practice, this means linking heat‑risk maps with population health data and care demand, connecting emergency planning with community support networks, aligning local authority adaptation plans with NHS resilience planning, and integrating nature‑based solutions into public health strategy. It enables the shift the National Emergency Briefing calls for: from reactive crisis response to anticipatory governance.

The National Emergency Briefing and the government’s own national security assessment are calling for much more than incremental reform. They are calling for a redesign of how the country understands and governs risk. Ecological breakdown is a common causative factor behind many of the national security risks we discuss most readily today. Dependence on fossil fuels shapes geopolitical conflict, including energy driven tensions such as those seen in Ukraine; degradation of natural systems increases the likelihood of zoonotic disease emergence and pandemics; and climate and ecosystem breakdown undermine food and water security, driving displacement, instability and conflict. These risks are often treated as separate issues, yet they share a common root. Health is where the consequences of this ecological breakdown ultimately surface.

The experience with Impact on Urban Health shows that a different model is already possible: one where climate, health and community development are planned together; where resilience is built from the ground up; and where institutions are equipped with the systems tools they need to act early rather than react late. This is what OnePlanet is for.