Climate Change and Global Health in the 21st Century: Evidence and Resilience

Abstract

Climate change and projected global warming have received much attention and engendered some debate in the scientific, health, and policy communities in the last two decades. Many discussions, primarily in United States, have focused on economic and scientific evidence. There is now persuasive evidence demonstrating the numerous health risks posed by climate change, which threatens populations of both low and high-income countries. These health effects include more frequent heatwaves, flooding and extreme weather events. Less direct impacts also include worsening food security, malnutrition and population displacement. Addressing climate change is also considered to be an opportunity to improve global health in the 21st century due to the significant health co-benefits of low-carbon solutions. The World Medical Association (WMA) follows the United Nations climate change negotiations so that the well-documented impact of climate change on health, as well as the public health benefits of climate change mitigation activities, are taken into consideration. Physicians advocate for making health an inherent component of the climate change debate and for an effective and ambitious implementation of the Paris Agreement adopted in December 2016. The World Health Organization (WHO) estimates that anthropogenic climate change of the past 30 years has claimed over 150,000 lives annually (Patz, Campbell-Lendrum, Holloway & Foley, 2005). Patz et al. (2005) carefully qualify that there is some uncertainty in attributing certain disease outcomes to climate change due to the “lack of long-term, high-quality data sets as well as the large influence of socio-economic factors and changes in immunity and drug resistance.” Predictive models to assess impacts of health threats from infections and undernutrition continue to evolve. Historical evidence supports claims of increased incidence of skin cancer (melanoma) due to ozone depletion (Pinault et al., 2017), and of allergies, cardiovascular disease, and death from thermal and hydrological disasters. Some health risks are attributed to the increases in atmospheric pollutants. Carbon dioxide's (CO2's) growth rate has more than doubled in the last three decades, a period of increasing global economic dependency on carbon-energy use (Canadell et al., 2007). Deforestation is considered the second largest anthropogenic source of atmospheric CO2, after fossil fuel combustion. Agriculture, ranching, logging for timber, increasing droughts, and forest fires also contribute to climate change and potential ecological disruptions, but the extent and severity of their contributions are still inadequately understood (Canadell et al., 2007; Heller and Zavaleta, 2008). The availability of an extensive, but aging, network of Earth's remote sensing satellites holds promise to produce needed evidence on the rate at which forests and oceans are capable of removing carbon dioxide, particulates, and greenhouse gases. Many robust regional studies suggest that a reduction in agricultural methane and nitrous oxide emissions, particularly in Southern Asia, may help mitigate climate change (Tian et al., 2016). The evidence supporting climate change and its effects on human and ecosystem health is undeniable. Concern with the significance of anthropogenic activities in accelerating warming or cooling trends is fair and requires further understanding. Governments should select promising areas of intervention while minimizing any negative impacts of clean energy technology on the ecosystem, learning from the experience of nuclear reactors. The rapidly expanding climate change knowledge base builds the scientific evidence informing policy interventions. The introduction by the U.S. Congress of the “Evidence-Based Policymaking Commission Act of 2016” (Public Law No: 114-140) should help foster a rational approach to climate change policy, and investment in mitigation strategies to ensure that measures are in place to protect our sole habitat in the solar system. Safe practices of reducing greenhouse emissions can only benefit human and ecological health. In the meantime, developing resilience strategies to deal with climate change is prudent and necessary.