Changes in Extreme Heat and Extreme Cold. A warmer future is projected to lead to “on the order of thousands to tens of thousands of additional premature deaths per year across the United States by the end of this century” from heat. Any reduction in cold-related deaths is projected to be smaller than the increase in heat-related deaths in most regions. High temperatures can also lead to a wide range of illnesses. Examples of illnesses associated with extreme heat include cardiovascular, respiratory, and renal illnesses; diabetes; hyperthermia; mental health issues; and preterm births. Even small differences from seasonal average temperatures result in illness and death. An increased risk for respiratory and cardiovascular death is observed in older adults during temperature extremes.Changes in Extreme Heat and Extreme Cold. A warmer future is projected to lead to “on the order of thousands to tens of thousands of additional premature deaths per year across the United States by the end of this century” from heat. Any reduction in cold-related deaths is projected to be smaller than the increase in heat-related deaths in most regions. High temperatures can also lead to a wide range of illnesses. Examples of illnesses associated with extreme heat include cardiovascular, respiratory, and renal illnesses; diabetes; hyperthermia; mental health issues; and preterm births. Even small differences from seasonal average temperatures result in illness and death. An increased risk for respiratory and cardiovascular death is observed in older adults during temperature extremes.Impacts on Air Quality. Changes in the climate affect the levels and location of outdoor air pollutants such as ground-level ozone and fine particulate matter. These changes in ozone are projected to lead to hundreds to thousands of premature deaths, hospital admissions, and cases of acute respiratory illnesses per year in the United States in 2030. In addition, the area burned by wildfires in North America is expected to increase dramatically over the 21st century due to climate change. Air pollution from wildfires can affect people far downwind from the fire location, increasing the risk of premature death and hospital and emergency department visits. Higher temperatures and increasing carbon dioxide levels also promote the growth of plants that release airborne allergens.
More Frequent and Intense Extreme Events. Climate change will expose more people to increases in the frequency and/or intensity of drought, wildfires, and flooding related to extreme precipitation and hurricanes. Many types of extreme events related to climate change cause disruption of critical infrastructure, including power, water, transportation, and communication systems, that are essential to maintaining access to health care and emergency response services and safeguarding human health. Health risks may also arise long after the event, or in places outside the area where the event took place, particularly if multiple events occur simultaneously or in succession in a given location – this could be the result of damage to property, destruction of assets, loss of infrastructure and public services, social and economic disruption, and environmental degradation. Poverty also is a key risk factor, and the poor are disproportionately affected by extreme events.
Altered Timing and Location of Vector-Borne Disease. Climate change is expected to alter the geographic and seasonal distributions of existing vectors and vector-borne diseases, such as Lyme disease, West Nile virus infections, and other diseases spread by vectors like mosquitoes. Rising temperatures, changing precipitation patterns, and a higher frequency of some extreme weather events associated with climate change will influence the distribution, abundance, and prevalence of infection in the mosquitoes that transmit West Nile virus, the leading cause of mosquito-borne disease in the United States. Outdoor workers are at a greater risk for contracting Lyme disease and, if working in areas where there are infected mosquitoes, occupational exposures can also occur for West Nile virus.
Increased Risks of Water-Related Illnesses. Runoff from more frequent and intense extreme precipitation events will increasingly compromise recreational waters, shellfish harvesting waters, and sources of drinking water, increasing the risk that infrastructure for drinking water, wastewater, and storm water will fail due to either damage or exceeding system capacity. Although the United States has one of the safest municipal drinking water supplies in the world, water-related outbreaks still occur—between 1948 and 1994, 68 percent of waterborne disease outbreaks in the United States were preceded by extreme precipitation events. Inequities in exposure to contaminated water disproportionately affects tribes and Alaska Natives, residents of low-income rural subdivisions along the U.S.–Mexico border, migrant farm workers, the homeless, and low-income communities not served by public water utilities—some of which are predominately Hispanic or Latino and African-American communities.
Increased Threats to Food Safety and Nutrition. As climate change drives changes in environmental variables, such as ambient temperature, precipitation, and weather extremes (particularly flooding and drought), increases in foodborne illnesses are expected. In the United States, the Centers for Disease Control and Prevention (CDC) estimate that there are 48 million cases of foodborne illnesses per year, with approximately 3,000 deaths. Rising levels of carbon dioxide in the atmosphere can lower the nutritional value of most food crops. Climate-change impacts on food production, food processing and utilization, food prices, and agricultural trade were recently addressed in a separate assessment report on Climate Change, Global Food Security, and the U.S. Food System.
Adverse Impacts on Mental Health. The cumulative and interactive effects of climate change, as well as the threat and perception of climate change, adversely impact individual and societal physical and mental health and well-being. Mental health consequences of climate change range from minimal stress and distress symptoms to clinical disorders, such as anxiety, depression, post-traumatic stress, and suicidal thoughts and behaviors. The mental health impacts of extreme events, such as hurricanes, floods, and drought, can be expected to increase as more people experience the stress—and often trauma—of these disasters. People with mental illness and those using medications to treat a variety of mental health conditions such as depression, anxiety, and other mood disorders are particularly vulnerable to extreme weather events and extreme heat.
Disproportionate Effects on Vulnerable Populations. Every American is vulnerable to the health impacts associated with climate change. People at every life stage have varying sensitivity to climate change impacts. The most vulnerable populations include individuals with low income, some communities of color, individuals with limited English proficiency and immigrant groups, Indigenous peoples, children, pregnant women, older adults, vulnerable occupational groups, persons with disabilities, and persons with preexisting or chronic medical conditions reported most commonly among adults aged 65 and older. The need to evacuate an area during or after extreme events can pose increased health and safety risks for older adults, especially those who are poor or reside in nursing or assisted-living facilities. Air pollution can also exacerbate asthma and COPD and can increase the risk of heart attack in older adults, especially those who are also diabetic or obese.
Occupational Groups. Outdoor workers are often among the first to be exposed to the effects of climate change. Climate change is expected to affect the health of outdoor workers through increases in ambient temperature, degraded air quality, extreme weather, vector-borne diseases, industrial exposures, and changes in the built environment. An increased need for complex emergency responses will expose rescue and recovery workers to physical and psychological hazards. The incidence of heat illness among active duty U.S. military personnel is several-fold higher than the summertime incidence in the general U.S. population (147 per 100,000 among the military versus 21.5 per 100,000 in the general population per year).
Persons with Disabilities. An increase in extreme weather can be expected to disproportionately affect populations with disabilities, who experience higher rates of social risk factors—such as poverty and lower educational attainment—that contribute to poorer health outcomes during extreme events or climate-related emergencies. Persons with disabilities often rely on medical equipment (such as portable oxygen) that requires an uninterrupted source of electricity.
Persons with Chronic Medical Conditions. Preexisting medical conditions present risk factors for increased illness and death associated with climate-related stressors, especially exposure to extreme heat. Hospital admissions and emergency room visits increase during heat waves for people with diabetes, cardiovascular diseases, respiratory diseases, and psychiatric illnesses. Medical conditions like Alzheimer’s disease or mental illnesses can impair judgment and behavioral responses in crisis situations, which can place people with those conditions at greater risk.
Source, U.S. Government