Extreme heat, health inequalities, and the net zero transition: future directions

As the UK progresses towards a net zero economy, rising temperatures and more frequent extreme heat events pose increasing risks to health and wellbeing, particularly for vulnerable populations. The 2022 heatwave, with temperatures over 40°C and more than 3,200 excess deaths, exposed limitations in current policy frameworks for addressing the interconnected challenges of climate mitigation, adaptation, and health equity. Despite projections indicating that up to 90% of homes may soon face overheating risk, building regulations and energy demand policies remain insufficiently aligned with emerging climate projections.

This paper introduces HEARTH, a newly established five-year, £7.4 million (€8.6 million) national research hub that examines the intersection of extreme heat, health inequalities, and the net zero transition. HEARTH adopts a stakeholder-led, whole-systems, mixed-methods approach to investigate how net zero interventions can deliver health co-benefits while reducing heat-related risks in vulnerable settings. The programme focuses on populations most at risk, including older adults, individuals with chronic conditions, and people living or working in confined or institutional environments.

The research integrates multi-scale climate modelling, from regional and urban climates to neighbourhood, building, and indoor environments, with empirical data on heat exposure, occupant behaviour, and physical and mental health outcomes across more than 200 monitored settings. HEARTH evaluates the health, equity, and economic impacts of interventions, including retrofit strategies, climate-resilient new construction, and nature-based solutions. The paper concludes by outlining research priorities and policy directions needed to ensure that the transition to net zero strengthens climate resilience and reduces health inequalities rather than exacerbating them.