Ireland's State of the Environment Report 2024

392 Chapter 14: Environment, Health and Wellbeing 4. Climate change and health The climate crisis is a human health crisis. It represents the single greatest health threat facing humanity and is also a ‘threat multiplier’ compounding and exacerbating many significant environmental and health challenges. For example, climate change is fuelling an increase in the incidence and severity of many infectious diseases. A recent global systematic study examining the interactions of climatic hazards linked to human pathogenic diseases found that 58% of 375 diseases examined have been aggravated by climate change (Mora et al ., 2022). In Ireland, flood hydrometeorology was shown to be associated with the incidence of gastroenteric infections caused by STEC/VTEC and Cryptosporidium spp. following the winter of 2015/2016, in which exceptional and widespread flooding was experienced (Boudou et al ., 2021). Ireland’s warmer winters now also have the potential to increase the numbers and activity of ticks and to extend their lifespan. Ticks are efficient vectors that host and can transmit an increasing number of pathogens to humans, including Lyme disease (Lambert, 2022). At a European level, the ECDC has reported a large increase in the geographical spread of a species of mosquito across previously unaffected areas (ECDC, 2023). The mosquito, which is a known vector for many diseases including dengue fever and yellow fever has now established itself in 13 EU and EEA countries compared with only eight countries 10 years ago. Climate change, combined with other challenges, such as population growth, urbanisation and globalisation, is narrowing the interface between humans and the natural world, bringing zoonotic diseases physically closer to us. We now live in an increasingly interconnected world, with over half the world’s population residing in urban areas and billions of us taking airline flights every year, making us increasingly vulnerable to the threat posed by infectious diseases (Baker et al ., 2022). Continual degradation of our environment, coupled with climate change, increases the risk of emergence of disease from zoonotic reservoirs; the probability of us experiencing another extreme epidemic or pandemic similar to COVID-19 in our lifetime is currently estimated at 38%, which may double in years to come (Marani et al ., 2021). High water levels at St Vincent’s Bridge, Cork City At a national level, we need to place human health and wellbeing at the forefront of our climate preparedness and action. We need to prioritise and fast-track the implementation of ambitious climate adaptation and mitigation measures that can deliver health co-benefits, particularly to those vulnerable populations most affected by climate change. Modelling has indicated the potential health gains that can be accrued from health-focused mitigation actions tackling emissions while simultaneously taking action on air pollution, active travel and diets (Hamilton et al ., 2021). There is a wealth of evidence on climate actions that can deliver health co-benefits. What is now required is a step change in the translation and implementation of practical actions at national and local levels to effect impactful and measurable change. COP28 (United Nations Climate Change Conference) in 2023 was the first to dedicate a day to focusing on health. We need to follow this global ambition and put health at the forefront of our national climate discussions and policies to safeguard current and future generations.