The interplay between climate change and ageing: A systematic review of health indicators

displacement [24, 25]. Populations that are most vulnerable to these health impacts include older adults, young children, outdoor workers, and individuals with chronic medical condi- tions, weakened immune systems, limited access to healthcare, and inadequate access to clean water and nutritious food. Climate change exacerbates these vulnerabilities, highlighting the urgent need for adaptation and mitigation strategies to address these health impacts [26]. The urgency of addressing healthcare solutions in light of climate change has significantly height- ened. Age, together with gender, low socioeconomic status, social isolation and low level of education, are some of the factors that increase individuals’ and groups’ vulnerability, with the older population being a prime example [27]. Additionally, there are psychological factors that can modulate individuals’ vulnerability to climate change. For instance, the psychological dis- tance factor. This implies that people tend to perceive climate change as a more immediate concern when they see it as closer to them in both time and place. This heightened sense of closeness often results in a greater willingness to embrace pro-environmental and adaptive behaviours. Conversely, when individuals perceive climate change as more distant in time or place, it tends to create a more abstract representation of the issue [28, 29]. Literature has descriptively presented the challenges that relate to climate change and the implications for the health of older adults—in its different manifestations. Limitations such as

small sample size studies or limited data availability usually restrict the statistical power and generalizability of the findings. Additionally, information is still scarce, and further research is needed, with regard to measurable indicators related to the impact of certain phenomena (heat waves, intense rains, air pollution, among others) on the physical and mental health of older adults [11, 30–33]. The studies that provide concrete indicators of the impact of climate change on the health of old adults give further information for the definition of public policies aimed at adapting public spaces, developing information and training processes, as well as promoting access to mechanisms that mitigate exposure to risk factors such as variations in temperature. Thus, it is also important to have a better awareness of the relationship between ecological, socioeco- nomic and health determinants to consider about the built environment in order to adapt to climate change, ensuring a better quality of life for all citizens particularly, the most vulnerable such as the older adults [30, 34]. To our knowledge, and to date, there are no systematic reviews exploring global climate change scenarios and their corresponding health outcomes in older people. Therefore, the objective of this systematic review is to collect quantifiable health indicators that establish a connection between climate change, the older population, and their physical and mental health. This review endeavors to furnish a substantial level of evidence and benefit research

groups, policymakers, funding agencies, and other stakeholders involved in this field. By pro- viding these professionals with prompt access to the most recent information in patient health- care management, this review aims to support their practice and assist in the development of future research programs and trials. Materials and methods The methodology employed for this systematic review adhered to the guidelines outlined in the Cochrane Handbook for Systematic Reviews of Interventions [35]. In order to ensure that this systematic review effectively addresses a relevant question and provides meaningful benefits to the scientific and healthcare community, the input of experts with diverse and noteworthy backgrounds was sought throughout the entire process—from identifying the review question to selecting the final articles. The protocol for this systematic review is registered on PROSPERO under the registration number CRD42022366182. PLOS ONE Climate change, ageing and health PLOS ONE | https://doi.org/10.1371/journal.pone.0297116 April 24, 2024 3 / 17