Climate Change – A Threat to Human Health

Climate change is causing various adverse effects on human health, including the increased frequency and severity of extreme weather events, degradation of air quality, and spread of insect-borne diseases. Adaptation measures such as improving infrastructure to withstand adverse weather and providing adequate healthcare services in areas most vulnerable to climate change effects could help mitigate its negative impact.

While there is no direct correlation between climate change and the deterioration of human health, there are indirect consequences. In the last century, the planet had warmed up by 1.1°C, causing huge shifts in weather patterns. As the earth heats up, the sea level rises, thereby increasing the frequency and severity of floods, droughts, heat waves, and storms. Certain populations – such as children, the elderly, the impoverished, and those with medical issues – are more susceptible to the harmful effects of climate change. Moreover, WHO estimates climate change would result in 250,000 additional deaths annually from 2030 to 2050.

Direct health damage expense globally is projected to reach USD2–4 billion per year by 2030 (excluding cost in health-determinant industries such as agriculture, water, and sanitation). Regions such as emerging economies, which have limited health infrastructure, are least equipped to manage without support to plan and respond to climate change.

Some of the deleterious effects of climate change are mentioned below:

• Insect-borne diseases – Rising temperatures have led to a shift in rainfall patterns across the world. Due to the shifting patterns, tropical regions have increased longitudinally to include portions of temperate regions receiving extensive rainfall. This has enabled mosquitoes and other insects to thrive in such areas and transmit fatal diseases such as dengue, West Nile virus, and Lyme disease. Furthermore, malaria-carrying mosquitoes have already been able to move to more temperate locations, expanding their range by around 6.5 meters per year and moving 4.7 kilometers away from the equator. Hence, insect-borne diseases are on the rise globally.
  
• Water scarcity and malnutrition – Water scarcity is a major concern as global temperatures soar. The sources of freshwater are melting at an alarming rate, leading to shortage of water for drinking, agriculture, and sanitation. This shortfall can lead to growth in waterborne diseases, including cholera and dysentery, which are caused by the consumption of contaminated water. Malnutrition is a severe health issue that is associated with climate change-induced water scarcity. Droughts and water shortages can cause crop failure and reduced agricultural productivity, leading to food scarcity. Additionally, water availability and quality changes can impact crop nutrient content, resulting in lower yields and nutritional value. Malnutrition and water scarcity can lead to various health issues, including stunted growth, weakened immune systems, and increased vulnerability to infectious diseases. Children are particularly susceptible to these effects, as malnutrition during critical developmental stages can cause long-term health problems.

• Air pollution – Air quality is a critical factor that influences human health, and climate change degrades air quality by contributing to ground-level ozone formation and increased particulate matter pollution. Ground-level ozone is a harmful pollutant that is formed when emissions from vehicles, industrial facilities, and other sources react with sunlight. Due to the higher temperatures, there are more chemical reactions occurring in the atmosphere. Ground-level ozone, a potent respiratory irritant, can cause chest pain, coughing, throat irritation, and other respiratory problems. Particulate matter is another air pollutant with tiny particles that penetrate deep into the lungs and can cause numerous health problems. Climate change has worsened particulate matter pollution owing to the increased frequency and intensity of wildfires, which release large amounts of particulate matter into the air. Higher temperatures and drought conditions can also result in more dust storms. According to the United Nations Environment Program, in 2019, about 99% of the world's population lived in places that did not meet WHO 2021 air quality guidelines. Evidently, most people are exposed to unhealthy air pollution levels that cause respiratory problems, cardiovascular disease, and other illnesses.

• Displacement and migration – Climate change is expected to result in migration. Over 170 million individuals worldwide could face internal displacement by 2050 owing to the gradual and cumulative effects of climate change. This estimation is derived from a pessimistic outlook characterized by elevated emissions of greenhouse gases and a disparity in development. Under a more environmentally sustainable scenario, this number would still amount to approximately 125 million climate migrants, while a more inclusive approach to development would result in an estimated 78 million migrants. Regardless of the specific scenario, it is noteworthy that within the six regions examined, Sub-Saharan Africa is anticipated to witness the maximum displacements owing to alterations in water availability, crop productivity, and rising sea levels.
• Mental health – The mental health consequences of climate change can be direct or indirect. For example, individuals who experience the trauma of a natural disaster or extreme weather may develop post-traumatic stress disorder or other mental health issues. Long-term exposure to climate change-related stressors, such as prolonged drought or food insecurity, can lead to chronic stress, anxiety, and depression.

Conclusion

To address the health impacts of climate change, it is imperative to take a comprehensive and collaborative approach that incorporates policy interventions, public health initiatives, and community-based strategies. This approach should prioritize efforts to reduce carbon emissions, increase public awareness and promote education about climate change effects, and strengthen the healthcare systems and services needed to respond to climate change-related emergencies.

Mitigating the health impacts of climate change requires a collective effort that integrates policy and community engagement. We can build a more resilient and sustainable future for all by working together.