The Multifaceted Consequences of Climate Change on Human Health

Abstract

Human health, worldwide, is in great peril due to pollution and climate change. The sheer scale and expanse ofclimate change manifested as extreme weather conditions, changes in air quality, natural calamities, and vectorecology are negatively impacting human health. Frequent floods, wildfires, erratic rainfall, sea-level rise, andcyclones were documented across the globe in countries including Australia, Algeria, Brazil, China, Italy,Greece, Malaysia, Nigeria, Pakistan, South Africa, Spain, Türkiye and USA.1 The growing number of adversehealth outcomes due to climate hazards is increasing the burden in the health services already impacted by theCOVID-19 pandemic, co-epidemics (e.g., human immunodeficiency virus and tuberculosis) and double burdenof disease (communicable and non-communicable diseases). Anthropogenic activities have drasticallyincreased atmospheric greenhouse gas levels leading to a significant increase in the global mean surfacetemperature by 1.1° Celsius, warmer than the pre-industrial levels. The past seven years were declared thewarmest, the 1.5-degree climate target agreed upon at the Conference of the Parties (COP21 )in Paris seems far out of reach as the global mean surface temperature is projected to rise to a dangerous level of between 1.5oCelsius and 3.5 Celsius by the end of this century.1
 The ongoing climate stressors affect the populations that are most vulnerable and marginalised, like olderpeople, pregnant women, new-born babies, people who are socially deprived and people working outdoors.Human exposure to intense heat is associated with heatstroke, adverse pregnancy outcomes (includingpremature birth), acute kidney injury, disturbed sleep patterns, mental health problems, cancers andworsening of underlying respiratory and cardiac disease. Annually, three million deaths are attributable toinfections caused by outdoor PM2-5 air pollution.1 Asthma, the most common respiratory illness amongadolescents, is influenced by higher and longer pollen seasons and poor air quality, increasing the risk of acuteasthma episodes. Vector-borne diseases like malaria and dengue have increased in Africa and Asia. Rare severeinfectious diseases caused by Naegleria fowleri, Nipah virus, and Coccidiodes spp have also increased.
 Extreme climate events also disrupt the food supply; leading to malnutrition and disease susceptibility. Humancontact with environmentally mediated pathogens through food, water, animals, or insect vectors, causessubstantial morbidity and mortality globally. Waterborne diseases are rising globally, especially in LMICs, withoutbreaks of diarrhoea, hepatitis, cholera, malaria, dengue, salmonellosis, typhoid, dysentery, schistosomiasis,and giardiasis.2 Moreover, Vibrio pathogens are more transmissible due to rising coastal water temperatures. In Pakistan, waterborne diseases are becoming more frequent due to climate-based increased variations intemperatures and rainfall patterns, which have led to the challenges of water unavailability and exposure tounsafe water. In 2017, an epidemic of drug-resistance typhoid resulted in an untreatable and prolongedinfection in Pakistani citizens resulting in many deaths in children below 15 years of age.
 The footprint of climate change is becoming more extreme in South Asia; India, Pakistan and the Philippinesare in the “high” bracket” of the vulnerability assessment that has been most severely impacted by extremeweather events, according to the latest report by Intergovernmental Panel on Climate Change (IPCC). Pakistan,a negligible contributor to the overall carbon footprint, is still among the top ten countries vulnerable to climatechange by Global Climate Risk Index 2021.1 The recent heavy rainfall and floods in Pakistan have resulted in theloss of life and livelihood. Human suffering, socioeconomic constraints, involuntary migration anddisplacement in climate emergency are massive.
 The response to the needs of the disaster-affected population remains a key challenge in terms of resourceconstraints, afflicted health systems, changing disease burden, the provision of shelter and emergency reliefitems, delivering lifesaving and livelihood assistance, water, sanitation and hygiene (WASH) needs, preventionof disease outbreaks, addressing malnutrition, Gender-based violence (GBV), Psychosocial Support (PSS),dignified protection, and family tracing.
 The recent 2022 United Nations Climate Change Conference (COP27) concluded with a cover decision known asthe Sharm el-Sheikh Implementation Plan. COP27 concluded to provide “loss and damage” funding forvulnerable countries hit hard by climate disasters. The other decisions included cutting greenhouse gasemissions and adapting to the inevitable impacts of climate change, boosting finance and technology support,and widening the capacity building needed by LMICs.
 The planet's warming is jeopardising human health, demanding immediate climate action for mitigation andadaptation, fossil fuel reduction, building resilient communities, investing in emerging green technology, andintegrating climate education into medical and school curricula.1-3 In our efforts towards a sustainable planet, itis critical to accelerate climate action by strengthening multisectoral engagement.
 Editor-in-Chief
 How to cite this: Alamgir W, Shan H. The Multifaceted Consequences of Climate Change on Human Health. Life and Science. 2023; 4(1): 1-2. doi: http://doi.org/10.37185/LnS.1.1.343