Managing and Mitigating the Health Risks of Climate Change: Calling for Evidence-Informed Policy and Action

The recent United Nations climate treaty achieved unprecedented international support. Representatives from 195 countries met in Paris in December 2015 and agreed to lower their greenhouse gas emissions—an important step towards avoiding many impacts of climate change later this century (Karliner 2015). Climate change affects many natural and social systems and processes necessary for civilization (Pachauri et al. 2014; Patz et al. 2014; Watts et al. 2015). It disrupts the Earth’s lifesupport systems that underpin the world’s capacity to supply adequate food and fresh water and the eco-physical buffer against natural disasters. These natural systems underlie the attainment and maintenance of good health and well-being in human populations. Climate change is increasingly recognized as the biggest global health threat (Costello et al. 2009) and opportunity (Watts et al. 2015). Understanding its present and future impacts on population health is of vital scientific and public health importance locally, nationally, and internationally. To date, public concerns and scientific endeavors focused largely on the risks of climate change to economic productivity, livelihoods, tourism, infrastructure, and valued species (McMichael 2012; Smith et al. 2014). For example, pollinators are a key component of global biodiversity, providing vital ecosystem services to crops and wild plants. Global pollinator declines are reported to be associated with habitat loss and fragmentation, agrochemicals, pathogens, alien species, and climate change (Potts et al. 2010). There is now an increasing recognition of its potential risks to human health that are not only related to disasters but also to significant changes in climate systems such as increasing temperatures and altered rainfall patterns. Tackling climate change could be the greatest global health opportunity of this century. Many mitigation and adaptation responses to climate change could lead to direct reductions in the burden of ill health, enhance community resilience, alleviate poverty, and address global inequity (Watts et al. 2015). To address the scale and immediacy of the threat of climate change to human health and well-being, there is an urgent need to develop evidence-informed policy guidelines for action. The Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5) concluded that, globally, rising temperatures and changing rainfall patterns were linked to a range of health outcomes (IPCC 2014). Climate change-related alterations in weather and climate patterns would affect many determinants of health (e.g., thermal stress, floods, storms, droughts, bushfires, and food and water quality and quantity), and the geographic range and activity of infectious diseases. It is important to update the current understanding of the health risks of climate change, to estimate their likely future trajectories, and to provide policy makers with the information needed to take proactive actions to protect individuals, communities, and nations from adverse effects of climate change. This information is within the context of changing population vulnerability. For instance, the world population is projected to reach 9.5 billion by the mid-2050s (mainly due to a growth in the Asian and African populations), and the proportion of the elderly 65 years old and older will more than double (Gerland et al. 2014). It is, therefore, reasonable to anticipate that the impact of climate change on the elderly will be more obvious and become a larger overall disease burden over the coming decades, unless proactive and efficient adaptation measures are implemented.