The health inequalities between different ethnicities, neighbourhoods and social classes are already stark, with millions of women in the most deprived areas in England dying almost eight years earlier than those from wealthier areas. But according to the UK Health Security Agency’s (UKHSA) report, these disparities will worsen as the impact the climate crisis has on health is disproportionately negative to the most disadvantaged groups. These particular groups include people with disabilities, homeless people and people living in local authorities with high levels of deprivation. Sir Michael Marmot, the director of the Institute of Health Equity and the author of the landmark Marmot review into health inequalities in 2010, said that climate breakdown can make health inequalities worse. “Extremes of heat and cold associated with climate change increase mortality of vulnerable groups,” Marmot said. “In the UK, excess winter mortality is particularly high – higher than in colder Nordic countries. [This is] probably the result of cold homes which, in turn, is linked to fuel poverty.” Marmot added that the effect the climate crisis has on health inequalities is global and that the livelihood and health of people in low- and middle-income countries will be affected to a greater degree than those in high-income countries. He said: “Action to reduce greenhouse gas emissions should include housing, transport, work and food. Done with regard to equity, actions in these domains can reduce health inequalities. Clean transport, for example, will reduce air pollution at the same time as it contributes to net zero, with the effect of reducing health inequalities. Without regard to equity, climate-change action could make inequalities worse.” Prof Lea Berrang Ford, the head of the Centre for Climate and Health Security at the UKHSA, made it clear that the negative health effects of climate breakdown will not be distributed equally across the UK, social determinants or generations. The report said that children and young people will experience increasingly severe weather into their retirement, with effects persisting or increasing for their children. Ford said: “The distribution of the impacts of climate change do not just differ across geographic regions, but also across different socio-demographic groups. “Climate change is well recognised as likely to exacerbate existing health inequalities, and across a range of health impacts the most vulnerable groups are adults over 65 years old, children and those with pre-existing medical conditions.” Andrew Haines, a professor of environmental change and public health at the London School of Hygiene & Tropical Medicine, said that multiple threats to health from climate change will “amplify existing inequities in health”. He added: “There will also be geographic variation in impacts. For example, heat exposure is higher in urban areas and the risks of flooding are higher for populations living in low-lying areas and coastal regions.” For Prof Kristie L Ebi, of the Center for Health and the Global Environment at the University of Washington, the projections the report made are “concerning, compelling, and policy-relevant”, while “demonstrating the magnitude and pattern of health risks in the UK” in a changing climate. She added: “Even with timely and effective adaptation, and rapid reductions in greenhouse emissions, there will be residual risks that health systems will need to manage. Filling the research gaps will help ensure that interventions to address the health risks will further identify vulnerable populations and interventions to protect and promote health while decreasing inequities. The results of the negotiations at Cop28 will be critical for determining the future health risks of climate change.”