In the brutal heatwave of July 2022, when the UK experienced temperatures of 40 degrees for the first time, more than 1,000 people died across England and Wales. In our most recent heatwave in mid-June 2025, researchers predicted more than 500 excess deaths in a single day. As climate change continues and such heatwaves become more frequent, death tolls will rise. But will they rise equally across society – or will some individuals and communities suffer more than others?

We convened a group of 25 experts in climate and heatwave resilience, vulnerability and inequality to examine how wealth inequality in the UK affects our ability to respond to extreme heat events, and in particular:

• How wealth inequality increases the vulnerability of key groups in society to heatwaves
• How wealth inequality undermines the feasibility and effectiveness of some of the main heatwave adaptation measures
• What we can do to reduce the negative impacts of wealth inequality on our ability to respond to extreme heat, both through targeted interventions and through broader measures to reduce wealth inequality and its impacts on our society and economy

The workshop followed a similar event on wealth inequality and societal collapse, Inequality Knocks, hosted by King’s College London and the Fairness Foundation in November 2024.

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Britain is a wealthy country, but its wealth is increasingly concentrated in few hands. While wealth inequality has remained fairly stable in relative terms over recent decades (with the richest 10% owning about 60% of the UK’s wealth), substantial rises in the value of assets between 2011 and 2019 increased the absolute wealth gap between the richest and poorest households by 50%, to a level that is second only to the USA among OECD countries. As a result, wealth – or its absence – has a bigger impact on people’s lives than ever before, from their housing to their health. Wealth inequality is distinct from both income inequality and poverty, but all three are related, which complicates efforts to tease out their downstream impacts.

Wealth inequality fuels inequalities in public health, with those living in the most deprived areas living 7-9 years less than those in the least deprived areas. People in less wealthy communities also cope with more long-term illnesses compared to wealthier individuals, who can afford better quality housing, food, and lifestyles. Higher levels of wealth inequality are associated with greater anxiety, stress and psychological distress due to increased negative social comparisons, and the cognitive burden of economic insecurity.

Large wealth gaps are negatively correlated with the quality of social interactions. As individuals become more wary of those from different economic backgrounds, this breakdown in trust leads to reduced civic participation alongside people from different backgrounds. Social networks weaken and become more segregated along economic lines. Less wealthy households are particularly affected, finding it harder to build connections and more likely to experience social isolation.

Higher levels of wealth inequality are associated with higher levels of crime, particularly property and violent crimes. This relationship has been explained with reference to the effects of economic deprivation, whereby crime may be the only way left to access basic resources. Resentment brought on by higher levels of perceived inequality can erode social cohesion and weaken adherence to social norms.

Wealth inequality undermines access to good quality, affordable housing. Those who do not come from wealthy families are effectively locked out of the housing market because they cannot rely on parental wealth to help them afford the rising cost of housing. Private and social renters pay a far larger portion of their monthly income on rent and often suffer worse health outcomes due to poor quality housing.

With the increase in the value of absolute wealth and stagnating wages, it becomes harder for those from less wealthy backgrounds to become socially mobile and to move up into a higher wealth decile. Wealth affords several educational, health, employment, and other benefits that cannot be realised by the less wealthy, who are then less able to move up the socio-economic ladder.

Wealth inequality exacerbates the impact of extreme heat on vulnerable groups

At the individual or household level, people with less wealth are less likely to benefit from extreme heat risk mitigation and adaptation strategies than their wealthier counterparts, despite being more likely to be affected. For example, they are less likely to be able to afford cooling measures such as installing air-conditioning or shutters, as well as lower-cost approaches such as fans or repainting external walls white.

The less wealthy are more likely to work in jobs that mean that they are more exposed to extreme heat, working in healthcare, hospitality/kitchens, construction, and other gig-economy jobs. In contrast, people who can work remotely or from home are more able to stay cool during periods of extreme heat because they are less directly exposed.

The less wealthy are more likely to live in over-crowded, poor-quality housing than their wealthier counterparts. With poorer households living in insecure, unsafe housing, their risk of mental and physical health issues is greater, making them more vulnerable to the impacts of extreme heat.

Should they need support to address these health issues, poorer households are less able to access timely, quality healthcare, leading to much worse health and mortality outcomes. The less wealthy are more reliant on accessing public services, such as healthcare and public transport, but due to a lack of government investment in extreme mitigation and adaptation in these sectors, they are more impacted by the effects of extreme heat on these services.

Inequality undermines civic participation: those with less wealth are less likely to engage and have their interests represented in public policy decisions. Their experiences and insights are less likely to be incorporated in community and national risk mitigation and preparedness strategies.

There is a feedback loop in operation, since climate breakdown can reinforce poverty and wealth inequality. Increases in temperature over time have a larger effect on poorer households than wealthier households and can increase wealth inequality. Poorer households are less able to absorb price shocks from extreme heat on energy, water, and food prices for example, which can increase due to the effects of extreme heat on supplies of basic goods.

Wealth inequality exacerbates the risks of extreme heat at a societal level

More broadly, wealth inequality undermines our society, economy and democracy, undermining economic growth and people’s access to opportunity, and reducing the strength of our democracy. These impacts interact and reinforce each other. Lobbying by wealthy elites can undermine progress on net zero as well as on tackling the wealth inequality that exacerbates its impacts. The under-taxation of wealth, combined with sluggish economic growth, reduces the available funding for public services that indirectly mitigate against the impacts of extreme heat, as well as for direct mitigation strategies such as retrofitting houses or investing in heat-resilient public infrastructure.

And finally, wealth inequality damages social cohesion and resilience to extreme heat and other climate risks. Wealth inequality can lead to heightened corruption and poorer decision-making that benefits the elite rather than the public good. This makes it harder for institutions to effectively adapt to changing circumstances, while reducing public faith in politicians and increasing public discontent. Taken together, these dynamics increase the risks of societal unrest and, eventually, societal collapse, as we explored in the previous workshop.

To explore the evidence base in more detail, please see the Wealth Gap Risk Register.

A central theme throughout the workshop was the recognition that wealth inequality is a fundamental driver of vulnerability to extreme heat. While wealth and income are closely linked, they are not interchangeable; financial wealth provides a buffer for unexpected costs, such as retrofitting homes or purchasing air conditioning, whereas income affects day-to-day resilience. Low-wealth households and communities are disproportionately affected by extreme heat, as they have fewer resources to adapt, lower-quality housing, and less access to green spaces or cooling centres. These communities also face greater health risks, with pre-existing conditions such as obesity, diabetes, and mental health issues being more prevalent and exacerbated by heatwaves.

At the societal level, wealth inequality was seen as both a driver and amplifier of broader social, economic, and political risks. The UK’s centralised governance and underfunded public services mean that councils in low-wealth areas struggle to provide adequate emergency responses, maintain infrastructure, or fund adaptation measures. This leads to a cycle of declining public trust in institutions, as people perceive that the system is not working for them. The workshop highlighted how wealthy individuals and communities have greater influence over policy, often shaping adaptation measures to their own advantage, while the needs of the most vulnerable are overlooked. This dynamic undermines social cohesion and increases the risk of unrest, particularly in deprived areas where frustration and anger can boil over during prolonged heatwaves.

The workshop also explored the practical challenges of implementing adaptation measures in the face of wealth inequality. For example, retrofitting homes for heat resilience is expensive and often inaccessible to renters or low-income households, while green infrastructure projects tend to benefit wealthier neighbourhoods first. Cooling centres and other public services are more likely to be underfunded or overcrowded in low-wealth areas, and digital exclusion can prevent vulnerable groups from accessing critical information during emergencies. Participants stressed the importance of community engagement and co-design in developing adaptation strategies, but acknowledged that these processes are resource-intensive and can be dominated by more vocal or privileged groups.

Participants worried that the government’s response would be inadequate, hampered by underfunded public services and a lack of political will to address underlying inequalities. There was scepticism that even a catastrophic event would prompt radical policy change, given the inertia and vested interests within the current system, as well as the absence of significant reforms after events such as the COVID pandemic and the 2022 heatwave.

The workshop identified a range of potential interventions to address these challenges, including progressive taxation (such as taxing wealth) to generate more revenue to support adaptation measures, stronger and better enforced regulations to improve minimum standards in key areas such as housing, and more investment in public services and the social safety net to reduce the degree of vulnerability of disadvantaged groups. There is a clear need for systemic change to address the root causes of inequality and vulnerability, including strengthening our regulatory system as well as investing in human, social and physical infrastructure.

Drawing parallels with the social determinants of health, the workshop reinforced that addressing the root causes of vulnerability is more effective, less costly, and less controversial than reactive measures. As with public health, early prevention is better than late cure. It is much better – more effective, easier, cheaper, less controversial - to tackle the underlying causes of vulnerability and lack of resilience to extreme heat than to put in place expensive and ineffective measures to try to cope with them after the fact. Ultimately, meaningful progress requires tackling both the causes of wealth inequality and its wide-ranging societal impacts.

However, the main barrier to progress was seen as political rather than technical or financial. Wealthy individuals have more influence over policy, which can lead to solutions that benefit them at the expense of the poor. The current political system was described as lacking the will or capacity to implement the necessary structural reforms, with wealth inequality undermining public trust and fuelling populist narratives. The workshop concluded that without decisive action to address wealth inequality, the UK risks a period of deep social deterioration, with extreme heat events acting as a catalyst for further instability.

Participants were clear that wealth inequality is a critical factor in determining who is most vulnerable to extreme heat in the UK, shaping both individual outcomes and broader societal resilience. Addressing these challenges requires more equitable distribution of resources, inclusive policy design, and a renewed focus on building trust and social cohesion. Without such action, the risks posed by extreme heat will continue to grow, with the most vulnerable bearing the brunt of the impacts.

Designing and running this workshop underscored the difficulty of facilitating conversations about deep structural issues, such as wealth inequality, that cut across disciplines and topic areas. It is much easier to identify problems and solutions when focused on the impact on heatwaves of ‘surface-level’ issues such as poverty and vulnerability, which have clear knock-on effects on individuals and communities. When we look at underlying, structural issues such as wealth inequality, the evidence base is patchier, the causal links are more hidden and more interlinked, so harder to discern and pull apart, and the solutions needed are more challenging and ambitious. Many of the impacts are indirect – such as the ways in which wealth inequality exacerbates poverty and vulnerability – while others are diffuse, such as the negative impacts of wealth inequality on broader societal cohesion and resilience. Finally, while income inequality and poverty are critical drivers of vulnerability in the short term, wealth inequality becomes more significant over time due to its systemic, far-reaching, and rapidly growing effects, and because it is inexorably growing over time, as Piketty identified (r>g).

How to respond to these challenges? We need more of these difficult conversations about deep, long-term, structural issues and their role in driving or exacerbating more obvious or immediate problems. We need more interdisciplinary and cross-sector discussion and collaboration. We need to broaden and deepen the evidence base (something that we at the Fairness Foundation are trying to do through our evolving Wealth Gap Risk Register). And we need to better communicate the existing evidence as to how wealth inequality exacerbates climate risks (alongside a range of other societal risks), while acknowledging that many of the immediate impacts of inequality on climate risks are more directly related to income than to wealth. We’re all learning to better understand and respond to these complex systemic issues.

Acknowledgements

This report is authored by:

• Will Snell, Chief Executive, Fairness Foundation
• Dr Jeni Mitchell, Lecturer in War Studies and Founder of the Future Threats Lab, King’s College London
• Suzanne Hall, Director of Engagement, The Policy Institute, King’s College London

We are grateful for the research assistance provided by Anita Sangha (Research Assistant at the Fairness Foundation) and Robert Millar (Research Assistant at the Future Threats Lab at King’s College London), and for additional facilitation support from the following researchers during the workshop:

• Jack Jeffrey, Researcher, Fairness Foundation
• Zachary Kallenborn, PhD candidate in the Department of War Studies, King’s College London
• Pablo Mathis, MA graduate in the Department of War Studies, King’s College London
• Gemma Smith-Bingham, MA graduate in the Department of War Studies, King’s College London

Thank you to our 25 participants for their time, energy and insights. We very much hope that they remain involved in the next phase of this project. As the workshop was held under Chatham House rules, we are not disclosing their identities or institutional affiliations.