Over recent years, there has been growing concern about climate change and human health. There is a growing consensus among the scientific community that climate change is the most significant environmental challenge facing our species since the dawn of industrialization. It is believed that climate change will continue to impact human health, the environment, and human biodiversity for the foreseeable future. While no single answer can protect human health from climate change, it is important to take steps today to reduce greenhouse gas emissions and to adapt to climate change. The Intergovernmental Panel on Climate change (IPCC) has provided a framework for the research and policy needs of the global community.
Climate change and human health can be characterized in four stages of extreme climate change with abrupt, intense, and persistent change. Climate change can exacerbate existing physical health risks or generate new public health threats through various pathways. First, climate-driven changes may increase vulnerability to heat and precipitation extremes, creating an increased risk for heat stress and heat stroke; they may also lead to elevated risks for reduced immunity to infectious disease and increases in airway allergy among both humans and animals. Temperature increases of three degrees or more are thought to increase the risk for fatal heat illness and death.
Secondly, climate change and health can impact the ecosystems and their biological systems. Human health is affected by the quality and extent of ecosystems and their ecosystems’ dependence on nature. In addition, ecosystems provide a protective shield from external risks such as pesticides, chemicals, and pollution. Lastly, the quality of ecosystems provides a support system for ecosystem management and restoration which, in turn, has positive impacts on human health. In the summary, we summarize the broader context of climate change and human health.
The changes discussed in this summary have both immediate and long-term impacts on the health of human beings. For the moment, let’s review some of the direct climate impacts on health. Heat stress can lead to increased vulnerability to illnesses, such as cardiovascular disease, which may aggravate existing conditions or cause new conditions; it can also lead to strokes and heart attacks. Extreme heat can kill. When extreme heat is beyond control, the resulting heat stress can cause cooling through evaporative cooling, leading to dehydration and heatstroke.
Climate change and health impacts associated with changes in temperature and precipitation have direct consequences on public health through targeted heat wave events, cold waves, and precipitation changes. The frequency and magnitude of these events can vary on short time scales, ranging from days to weeks to months to years. Furthermore, some regions are exposed to differing risks at different elevations, varying with exposure.
Climate change and health impacts associated with temperature and precipitation changes and other climate-related factors such as storm patterns, ice melt, and snow accumulation can lead to an increase in all types of infectious diseases, such as influenza, herpes, cholera, and relapsing fever. These pathogens can be spread rapidly through crowded settings during times of public gatherings, mass gatherings, sports events, and gatherings involving alcoholic beverages. Human pathogens can be spread through insect bites, contact with contaminated objects such as cosmetics, and aerosol spray containers. As well, pathogens can be transmitted through animals’ droppings and saliva, blood, and other bodily fluids.