Heatwaves
The incidence of high summer temperatures in the UK is currently 10-25% higher than it would be without climate change; the likelihood of very hot summers with more frequent heatwaves is predicted to be 50% more likely by 2050. Summer temperatures above 25°C are likely to increase everywhere across the UK; the south of England will be particularly impacted. Extremely hot nights, which are currently rare in the UK, will become a more common occurrence. Urban centres in the south, particularly London, will be at increased risk due to the urban heat island effect.
Heatwaves are linked to sharp increases in deaths. For example, during five heat periods between June and August 2022, about 3000 excess deaths were recorded in England and Wales. Older people are particularly vulnerable to adverse health impacts of heat exposure. With its ageing population, this puts the UK at particular risk from climate change-related adverse health outcomes. The UK Health Security Agency (UKHSA) reported significant excess deaths in the 65 years and over group during the 2022 heatwaves. Very young children are also vulnerable to heat-related deaths, with health impacts including dehydration, asthma and kidney disease. Heat exposure in pregnancy is linked to premature births, low birth weight and stillbirth. Heat stress can adversely impact mental health. Disrupted sleep patterns due to heat can contribute to mood fluctuations and increase stress, exacerbate pre-existing mental health illnesses like depression and anxiety, or cause new ones to emerge. Psychosis, hallucinations, and other neuropsychiatric symptoms can occur in cases of severe heatstroke, and those with schizophrenia are at an increased risk of mortality during heatwaves. These risks are set to worsen – UKHSA projects annual heat-related deaths to reach over 21,000 by the 2070s in a high-warming scenario.
Heatwaves place additional pressure on NHS infrastructure, ambulance and services. The incidence of overheating at NHS sites in England has almost doubled in the last five years (from 2,980 recorded incidences in 2016-7 to 5,554 in 2021-22). These overheating periods have resulted in failure of essential equipment, disruption of IT and laboratory services, occupational health risk to staff, and the cancellation of surgical procedures.
Heatwaves increase the risk of transport disruption and changes to human behaviour, which has been associated with increased incidence of violent crime. Extreme heat impacts the welfare of animals, including pets. Using the five domains model of animal welfare, which is used to examine the physiological and behavioural responses of animals to environmental stressors, climate change harms and has a significant impact on both wild and domesticated animals across all five welfare domains which includes nutrition, environment, physical health, behaviour, and mental state.
Drought
It is predicted that prolonged hot, dry weather will increase the likelihood of drought across all parts of the UK. England and Wales are particularly vulnerable. These dry spells are predicted to increase in severity as global temperatures rise above 1.5C, resulting in reduced water availability for crop growth and the security of local food production. Drought has been shown to increase the levels of psychological distress and can worsen mental health, particularly in the first three years of exposure. These impacts will also be felt across the world, threatening food security and health on a global scale.
Wildfires
In the UK, a combination of long spells of dry weather, which increases the accumulation of dry grass and wind, is leading to more frequent wildfires. These events present a direct fire risk to life, homes and infrastructure. Smoke from these fires results in respiratory and cardiovascular conditions for those affected. Wildfires are predicted to increase by 50% by 2100 with impacts across the UK.
Flooding
Flooding is a significant climate change challenge facing the UK. Vulnerability to high rainfall events and widespread flooding poses danger to life, damage to infrastructure and travel disruption. Levels of daily rainfall and the risk of river flooding are expected to increase across the country. In October 2023, storm Babet brought exceptional rainfall to parts of the UK. The Met Office issued two red warnings for rain, the wettest day on record was reported, and multiple flood warnings were issued. At least seven people were reported to have died as a result of the storm, hundreds of homes and businesses were flooded, roads and schools were closed, crops and livestock were lost, and tens of thousands of homes were left without power. The storm was one of multiple named storms that occurred in the final quarter of 2023, the like of which will become more frequent with climate change.
Essential services like health and social care, as well as other critical infrastructure, are exposed to the increasing risk of flooding, which can lead to disruption and cancellation of services. In the year April 2021-March 2022, there were 176 incidents of flooding across NHS England sites, the majority of which occurred in general acute hospitals (sites that provide inpatient medical care and other services for surgery, acute medical conditions and injuries). The East of England and London were the worst affected.
Flooding can undermine the delivery of health and care services and coverage of care to vulnerable facilities, such as care homes. At present, roughly 10% of UK hospitals are located in areas of significant flood risk, with a further 495 emergency services, 2474 GP surgeries and 2187 care homes at risk in England. Under both mild and more intense warming scenarios, the number of hospitals at risk is predicted to increase.
People who experience flooding are more likely to have symptoms of depression, anxiety and posttraumatic stress disorder (PTSD), even two years after the flood event. Elevated symptoms of mental health disorders are reported in those who have lived in the vicinity of a flood event, and observing the loss of health and social care services was a significant stressor associated with this flood-related mental health burden.