CLIMATE CHANGE IMPACT ON HUMAN HEALTH

                                                      Image courtesy of STAT News

In 2021, more than 200+ medical & health journals, including veterinarian journals, simultaneously published an editorial declaring climate change as the #1 “greatest threat to global public health.” A global escalation in temperatures of merely 1.5° C / 2.7° F due to continued human activities, including, but not limited to the burning of fossil fuels like coal, oil and gas which have increased atmospheric levels of greenhouse gas emissions like Carbon dioxide. CO₂ emissions are leading to global warming that raises atmospheric and ocean temperatures; subsequently, causing catastrophic extreme weather events. These extreme weather events negatively impacts humans physical and mental health; even decades long after the extreme weather event has passed. However, extreme weather events economic impact on a nations’ gross domestic product (GDP) seems to get more attention from the media.

EXTREME HEAT

According to a 2021 paper published in “Nature Climate Change” over 1/3 of all heat related deaths can be attributed to climate change extreme weather events. Although cold weather deaths outnumber those caused by extreme heat, at a global rate of 9 to 1, deaths caused by climate change related extreme heat events are increasing as populations not used to dealing with this increasing threat are caught unprepared. Current projections for a temperature rise of 4° C temperature narrows the delta of this ratio to 2.6 to 1. The heat wave of 2022 that hit Northern Europe that caused over 60,000 deaths was exasperated by a historical lack of air conditioners in most northern residential households; along with a vulnerable aging—albeit socially isolated—population. In heat related deaths heat, surprisingly, may not be designated as the primary cause of death; or in some cases not even as a contributing cause of death. These heat related deaths are often misidentified on death certificates designating the causes of death to preexisting chronic illness such as cardiovascular or respiratory diseases. Especially when the main culprit, extreme heat, caused by climate change, does not leave any apparent physical destruction to infrastructure like other climate change extreme weather events such as hurricanes and floods.

In mammals, thermal regulation is managed by sweating. The body uses the perfusion of blood to shunt the heat away from the inner core organs to the largest organ, the skin, by evaporating sweat off the skin where the heat is released through convection. But sweating is only effective in dry heat; in high humid temperatures the ambient air cannot effectively evaporate sweat (Moisture) off the skin. When the core body temperature becomes too hot it can progress to heat exhaustion which can cause organ failure or seizures.

The sum of a longer & hotter summer growing season + higher CO₂ levels in the atmosphere = an increase in plants and trees pollen levels exasperating respiratory illnesses and asthma symptoms caused by allergic reactions.

VECTOR-BORNE DISEASES

According to the Centers for Disease Control (CDC), “between 2003 and 2023, more than 1 million cases of vector-borne diseases were reported in the United States (U.S.) . . . as a result, illnesses like Lyme disease and West Nile Virus are increasing.” Warmer, humid weather is allowing the vectors of pathogens to live through milder winters. The regions of the ticks that spreads Lyme disease are expanding in their natural habitat of the U.S. east coast as it survives through milder winters.

CDC Epidemiologists attribute this increase in vector-borne disease carriers to changing rainfall patterns and rising temperatures that facilitate the growth of mosquitoes and tick populations. Climate Change has caused disruption in seasonal patterns creating longer hotter summers and warmer winters. The cold weather would normally eradicate these pest; keeping the population of vectors down. For instance, Pine bettles have been able to thrive during the mild winters of the western U.S. decimating large swaths of pine trees as they lay their eggs in the tree-bark for the larvae to feed on.

EXTREME WEATHER EVENTS EXASPERATED BY SOCIOECONOMIC STATUS

Global warming increases ocean temperatures (Ocean heat content) which causes the volume of sea levels to expand fueling the intensity and frequency of hurricanes and precipitation; with higher sea levels increase ocean surges. These apocalyptic weather events, caused by climate change, have lead to once every 100 years biblical flooding events to occur annually with each hurricane season—sometimes multiple time during one annual hurricane season.

According to Rachel Young, Environmental Economist, of the University of California, Berkeley, one of the authors of research that studied over 500 hurricanes and tropical storms across the U.S. in the past 60 years, revealed extreme weather events like the September 26 - 27, 2024 Category 4 Hurricane Helene, that struck the U.S. Eastern Carolinas, will cause an estimated 7,000 to 11,000 excess post storm deaths. Of these deaths, “Black populations are much more likely to die about three times greater than white populations.” Young said.

                                                                                     Image courtesy of the NYT

Regardless of the socioeconomic status of a population, the impacts of climate change can be felt throughout all the global inhabitants on the Earth—there are no safe havens. However, people from different educational & socioeconomic backgrounds face different levels of exposure to the impacts of extreme weather events by their ability to access healthcare, economic and remediation assistance. These vulnerable members of the population impacted by poverty, racism, age discrimination, lack of education and inequality . . . are impacted even more by extreme weather events caused by climate change. Climate change tends to compound the existing racism of environmental pollution often surrounds minority & impoverished communities.

The U.S. state of Texas experienced one of the hottest heat waves between January 1 to November 30, 2023 in the Lone Star State recorded history causing 334 extreme heat related deaths; 279 known deaths were identified in the previous Texas heat wave of 2022. A large number of low income and elderly Texas residents whom could not afford to keep their electricity on had their power turned-off by the utility companies subsequently, depriving them of access to therapeutic indoor air conditioning.

The Southwest states of California, Nevada, Arizona and Texas share the highest numbers of deaths caused by extreme heat in the U.S.; about 48% nationally.

AIR POLLUTION

Black Americans have the highest rates of deaths attributable to particulate matter less than 2.5 micrometers (PM 2.5) (approximately 1 ten-thousand of an inch) from air pollution, approximately 350 deaths per 100,000 compared to less than 100 deaths per 100,000 people for all other races. The impacts of climate change are exasperated when combined with a history of minority and low income redlined communities in proximity to environmental pollution from manufacturing & agricultural industries, carbon based fuel processing facilities\ and waste dumps that pollute the air and water where they live and work. According to Dr. Robert Bullard, known as the father of environmental justice, in the U.S. a persons residential Zip Code is an important “predictor of an individual’s health and well being.” “Redlined” neighborhoods, where large populations of minority and economically disadvantaged residents experience higher temperatures due to the heat island effect. These neighborhoods carpeted with thermal retaining concrete and asphalt often lack verdant green parks with grass, have less trees to provide shade trapping air pollution and heat during the day which then slowly releases long in to the humid evenings. The stagnant polluted air increases levels of ground level ozone which can damage lung tissue, irritate airways and reduce normal lung function.

                                                              Image courtesy of the WHO

Extreme weather events can no longer be reconciled as just natural phenomenon gone awry that are separate from the complicit actions of human caused climate change. Humanity possesses existing knowledge & technology to stop further accelerations of climate change than to remain idly by as more people on the Earth die from the devastating impacts of extreme weather events caused by climate change.

EDITORIAL

(Vicedo-Cabrera, A. M., Scovronick, N., Sera, F., Royé, D., Schneider, R., Tobias, A., ... & Gasparrini, A. (2021). “The burden of heat-related mortality attributable to recent human-induced climate change” Nature Climate Change, 31, May 2012, Volume 11, P: 492 - 500)

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