Health Impacts: Multiple Facts, Complex Connections and Urgent Actions
Highlight:? Climate change affects both the physical and mental health of human beings and has not received the emphasis it deserves. The health impacts of climate change are multifaceted and their causes are complex. More notably, they are strongly linked to social contexts: some groups in society are disproportionately affected. The reflection and action we need is wide-ranging. Although there has been some progress, we still need more innovative solutions.
Part 1: What is happening?
The impacts of climate change on human health are unfolding in multiple ways and are insufficiently recognized at the level they deserve. As the evidence is telling us, physical diseases are increasingly affecting human health under the influence of climate change. Heat-related diseases, cardiopulmonary diseases, diseases related to food and water resources, and infectious diseases caused by pathogens are all becoming more threatening as a result of climate change. Another point that should not be overlooked is the impact of climate change on mental health - increased extreme weather is hitting many communities with a heavy blow, while climate anxiety is germinating in many minds.
According to a study published in Nature Climate Change, which systematically searched for empirical cases of human pathogenic diseases affected by ten climate hazards that are sensitive to greenhouse gas emissions[i], 58% of global infectious diseases (i.e., 218 out of 375) are worsened at some point by climate hazards; 16% are sometimes reduced. The empirical cases reveal 1006 pathways by which climate change affects pathogens through different types of transmission. The sheer number of human pathogenic diseases and their transmission pathways exacerbated by climate hazards, and the inability of societies to fully adapt, underscores the urgent need to work on the root cause: reducing greenhouse gas emissions.
Another article from this journal quantifies heat-related mortality and finds that an important cause of heat-related deaths is anthropogenic climate change, with Southern and Eastern Europe having a relatively high burden of heat-related deaths in their populations. Between 1991 and 2018, there were 6 heat-related deaths per 100,000 people in selected countries/regions. On average, there were 2.2 heat-related deaths per 100,000 people in the overall study area.
In terms of mental health, disasters associated with climate change anomalies have displaced or killed large numbers of people, which can be extremely traumatizing for the survivors. And for those who are not directly impacted by extreme meteorological hazards, the psychological impacts are also present and worrisome. Researchers from the University of Bath and other schools spoke to 10,000 people in 10 countries, all of whom were between the ages of 16 and 25, to look into how they feel about climate change. Of those surveyed, nearly 60% reported that they felt either "very" or "extremely" worried about climate change, and more than half said climate change made them feel "afraid, sad, anxious, angry, powerless, helpless, and/or guilty" while positive feelings such as optimism were reported least among the respondents, which indicates relatively solid evidence for climate anxiety. A?poll?conducted by the American Psychiatric Association in 2020 showed that nearly 70% of adults in the country are at least somewhat anxious about what climate change will do to the planet, and slightly more than half are worried about what toll that will take on their mental health. These rates are likely to have increased after the global shock of COVID-19.
Part 2: Why is it happening?
The influences of weather and climate on human health are significant and varied, the origin of which is still under study by researchers over the globe. Here are a few existing ways that climate change poses threats to human health.
Temperature-Related Death and Illness
Hotter seasonal temperature than the average in the summer or colder seasonal temperature than the average in the winter cause levels of illness and death to increase by compromising the body’s ability to regulate its temperature or by inducing direct or indirect health complications. Among the direct health effects of heat waves can manifest themselves as heat-related diseases, including heat cramps, heat exhaustion and pyrexia. Of these, pyrexia is a fatal emergency, also known as heat stroke hyperthermia. Hypothermia?and frostbite are closely related to extreme cold. Temperature extremes can also worsen?chronic?conditions such as cardiovascular disease, and respiratory disease.?
Vector-Borne Diseases
More intense storms and consequent flooding can cause harmful substances from sewage treatment plants to leak back into waters and the food system, causing the spread of disease. Meanwhile, weather is also one of several major causes of infectious diseases that affect vectors and animal-to-human transmission. To be more specific, 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 virusand other pathogens by altering habitat availability and mosquito and viral reproduction rates. Another example is that ticks capable of carrying the?bacteria?that cause?Lyme disease?and other pathogens will show earlier seasonal activity and a generally northward expansion in response to increasing temperatures associated with?climate change.
An article published in Nature in April 2022 writes that virus spillovers are increasing and already occurring, and will accelerate over the next 50 years as a result of climate change, habitat destruction forcing animals to migrate, and increased human-animal contact. Vector-borne pathogens are expected to emerge or reemerge due to the interactions of?climate?factors with many other drivers, such as changing land-use patterns. The researchers concluded that by 2070, climate change could easily become the main (human) driver of cross-species virus transmission.
Air Quality Impacts
Changes in the climate affect the air we breathe, both indoors and outdoors. A warmer environment can change the growth cycle of plants, leading to an increase in allergies. Too much and too often precipitation can stimulate mold to grow wildly in the lungs, while drought can make the air dusty. These pollutants and airborne allergens can even creep into homes, schools and other buildings. All of these conditions can lead to an increase and worsening of respiratory conditions. Poor air quality, both outdoors and indoors, negatively affects the respiratory and cardiovascular systems of humans. Higher pollen concentrations and longer pollen seasons can increase allergic sensitization and asthma attacks, thus limiting human health across age groups or different work scenarios.
Water and Food Resources Related
领英推荐
Climate change is expected to affect fresh and marine water resources in ways that will increase people’s exposure to water-related contaminants that cause illness like waterborne diseases caused by bacteria in seafood foods such as oysters, and other pathogenic microorganisms such as salmonella as their distribution and activity may change. Moreover, climate change is very likely to affect global, regional, and local food security by disrupting food availability, decreasing access to food, and making utilization more difficult. Thus, this potentially leads to negative implications for human nutrition. In addition, biotoxins such as harmful algae and pesticides used in response to changes in agriculture can lead to a spike in neurological conditions.
Mental Health and Well-Being
The impacts of climate change on mental health and well-being are a component of the overall climate-related impacts on human health. The mental health consequences of climate change range from minimal symptoms of stress and distress to clinical disorders such as anxiety, depression, post-traumatic stress and suicide. Other consequences include impacts on the daily lives, perceptions and experiences of individuals and communities trying to understand and respond appropriately to climate change and its impacts. The mental health consequences rarely occur in isolation, but often interact with other social and environmental stressors. Many people exposed to climate-related or weather-related disasters experience stress and severe mental health consequences. Depending on the type of disaster, these consequences include post-traumatic stress disorder (PTSD), depression, and general anxiety. Additionally, an increase in extreme heat will increase the prevalence of illness and death in people with mental conditions.
References:
Mora, C., McKenzie, T., Gaw, I.M.?et al.?Over half of known human pathogenic diseases can be aggravated by climate change.?Nat. Clim. Chang.?12, 869–875 (2022). https://doi.org/10.1038/s41558-022-01426-1?
Vicedo-Cabrera, A.M., Scovronick, N., Sera, F.?et al.?The burden of heat-related mortality attributable to recent human-induced climate change.?Nat. Clim. Chang.?11, 492–500 (2021). https://doi.org/10.1038/s41558-021-01058-x?
Marks, Elizabeth and Hickman et al. Young People's Voices on Climate Anxiety, Government Betrayal and Moral Injury: A Global Phenomenon. Available at SSRN:?https://ssrn.com/abstract=3918955?or?https://dx.doi.org/10.2139/ssrn.3918955?
APA Public Opinion Poll – Annual Meeting 2020 (Interviews: 1,004 US Adults - Dates: September 14-16, 2020), https://www.psychiatry.org/newsroom/apa-public-opinion-poll-2020?
Carlson, C.J., Albery, G.F., Merow, C.?et al.?Climate change increases cross-species viral transmission risk.?Nature?607, 555–562 (2022). https://doi.org/10.1038/s41586-022-04788-w?
Schrock, G., Bassett, E. M., & Green, J. (2015). Pursuing Equity and Justice in a Changing Climate: Assessing Equity in Local Climate and Sustainability Plans in U.S. Cities.?Journal of Planning Education and Research,?35(3), 282–295.??https://doi.org/10.1177/0739456X15580022
Lemon SC, Joseph HA, Williams S, Brown C, Aytur S, Catalano K, Chacker S, Goins KV, Rudolph L, Whitehead S, et al. Reimagining the Role of Health Departments and Their Partners in Addressing Climate Change: Revising the Building Resilience against Climate Effects (BRACE) Framework.?International Journal of Environmental Research and Public Health. 2023; 20(15):6447.
Atwoli L, Baqui AH, Benfield T, et al. Call for emergency action to limit global temperature increases, restore biodiversity, and protect health. Lancet 2021; published online Sept 6. https://dx.doi.org/10.1016/S0140-6736(21)01915-2.
source: World Health Organization, Climate change and health, 2021-10-30, retrieved from: https://www.who.int/news-room/fact-sheets/detail/climate-change-and-health
source: Carlson, C.J., Albery, G.F., Merow, C.?et al.?Climate change increases cross-species viral transmission risk.?Nature?607, 555–562 (2022).?
source: Mora, C., McKenzie, T., Gaw, I.M.?et al.?Over half of known human pathogenic diseases can be aggravated by climate change.?Nat. Clim. Chang.?12, 869–875 (2022).?
source: Vicedo-Cabrera, A.M., Scovronick, N., Sera, F.?et al.?The burden of heat-related mortality attributable to recent human-induced climate change.?Nat. Clim. Chang.?11, 492–500 (2021).