Climate change, however, is turning out to be among the main security concerns for the world, while directly leading to humanitarian crises through changed and extreme weather events like heatwaves, wildfires, floods, tropical storms, and hurricanes. According to research, 3.6 billion people are said to live in highly vulnerable areas due to climate change, while the projections estimate that between 2030 and 2050, climate change could result in approximately 250,000 additional deaths annually due to undernutrition, malaria, diarrhea, and heat stress.
These are estimated at approximately US$2–4 billion per year until 2030 indirect damage costs to health, excluding health-determining sectors such as agriculture and water and sanitation. Regions with weak health infrastructure, mostly in developing countries, will face great difficulty coping without external assistance.
Climate change is a root cause of human health that involves the physical environment and all aspects of natural and human systems, including conditions of social and economic functioning of health systems. It acts as a threat multiplier that could undermine and even reverse decades of health progress. The evolving climatic conditions result in more frequent and intense events related to weather and climate, including storms, extreme heat, floods, droughts, and wildfires. These hazards also increase the risk of deaths, noncommunicable diseases, the emergence and spread of infectious diseases, and health emergencies.
The Intergovernmental Panel on Climate Change’s Sixth Assessment Report says climate risk manifestation is coming sooner and will be more serious than had been projected earlier. It added that adaptation will be increasingly difficult with rising global temperatures. Low-income countries and Small Island Developing States bear the brunt of the health effects of climate change, despite their very meager contribution to global emissions. In the past decade, mortality due to extreme weather events was 15 times higher in the more vulnerable regions as compared to less vulnerable ones.
This threatens health in many dimensions: from the death and illness caused by more frequent extreme high temperatures, floods, storms, and other weather events, disruption of food systems leading to undernourishment, increased zoonoses and food-, water-, and vector-borne diseases, and adverse mental health effects. Many social determinants of good health are likewise undermined, including livelihoods, equality, and access to healthcare and social support structures. The health risks associated with climate sensitivity differentially or more profoundly affect the most vulnerable or otherwise disadvantaged, such as women, children, ethnic minorities, poor communities, migrants or displaced persons, older populations, and people with comorbidities.
According to the WHO, 2 billion presently do not have access to safe drinking water, and 600 million fall sick due to foodborne diseases annually, with children under five accounting for 30% of foodborne deaths. Various climate stressors elevate the risks of waterborne and foodborne diseases. For example, in 2020, 770 million people went hungry, and this is thought to persist through much of Africa and Asia. Climate change modulates the availability, quality, and diversity of food, thereby exacerbating food and nutrition crises.
Temperature and precipitation changes facilitate the proliferation of vector-borne diseases. Deaths from those diseases, presently totaling over 700,000 annually, could increase with no preventive actions. Climate change also precipitates acute mental health disorders, such as anxiety and post-traumatic stress, to name a couple, and chronic ones driven by psychological factors such as displacement and breakdown in social cohesion.
Recent findings also link 37% of heat-related deaths to human-induced climate change. There has been a 70% increase in heat-related deaths among people over 65 within twenty years. Compared to the average between 1981 and 2010, there were 98 million more people who suffered from food insecurity in 2020. The WHO conservatively projects that 250,000 additional deaths each year in the 2030s will be caused by diseases such as malaria and flooding due to climate change.
The climate crisis will continue to undermine the gains of the past five decades in development, global health, and poverty reduction. This has numerous implications for ongoing efforts towards addressing health inequalities between and within populations. This irreversibly threatens the realization of UHC through several pathways, including exacerbating the burden of disease and heightening pre-existing barriers to the utilization of health services at times when these are needed most. More than 930 million people 12 percent of the global population at least 10 percent of their household budget to finance healthcare. With the poorest largely uninsured, health shocks and stresses already push around 100 million people into poverty annually; a situation climate change is worsening.
Because health effects due to climate change, up until the medium and short run, are determined mainly by population vulnerability, resilience to the current rate of climate change, and the degree and rate of adaptation; in the longer run, effects increasingly depend on the degree to which transformational action to reduce emissions is taken now and will depend on the dangerous temperature threshold and potential irreversible tipping points.
While no one is safe from these hazards, the first and worst victims of the health damages of the climate crisis are those who contribute least to its causes and who are least able to protect themselves and their families against it: people in low-income and disadvantaged countries and communities. The equity imperative of addressing the health burden of climate change should be underlined by the fact that parties who have been most responsible for the emissions shall bear the highest mitigation and adaptation cost, with emphasis on health equity and vulnerable groups.