Malaria is the most significant public health concern due to climate change. In highly endemic areas, malaria incidence is seasonal. In a study in India, researchers found a substantial relationship between malaria and extreme climatic events. El Niño events increased the risk of malaria epidemics by five times. Moreover, increased rainfall during the monsoon period influenced the breeding of mosquitoes.
As temperatures in the Arctic circle increase three times faster than in the rest of the world, old infectious diseases could reappear. There is the potential to reintroduce deadly diseases such as the 1918 Spanish influenza virus.
Researchers have estimated the burden of diseases attributable to climate change in five geographic regions. The results show that climate change-induced health risks are higher in households with chronic illnesses and those with weakened immune systems. Moreover, those who perform physical labor will be more susceptible to extreme heat and dehydration, and they may even suffer cardiac arrest or kidney damage. The research findings highlight the importance of identifying the effects of climate change on public health and reducing greenhouse gas emissions.
Heatwaves are also becoming more frequent and intense, resulting in higher temperatures and mortality rates. The risks are especially severe for older people, very young children, and people with respiratory conditions. Even healthy individuals are vulnerable to heat-induced illnesses when exposed to high temperatures for long periods. Heatwaves in the 2020 Siberian summer were 600 times more likely than in a world without climate change.
These heat waves are hazardous for those working outdoors, and they can damage the brain, heart, and kidneys. Previous studies have linked climate change-fueled heat waves to higher mortality risk. For example, a study from 2003 related climate change to a 70% increase in death in Paris, France.
One in three heat-related deaths can be traced to climate change. In developing countries like Guatemala, Kuwait, and Iran, the numbers are even higher. In Ecuador, the heat is extreme, and air-conditioning is unavailable to all households. The elderly and socially isolated are more likely to die of heat-related deaths, and people with chronic conditions are also more susceptible to high temperatures.
As climate change intensifies and natural disasters become more widespread, the risks to low-income people increase. Last year, for example, 396 disasters affected over 95 million people worldwide and cost an estimated $103 billion in damages. The impacts of natural disasters are challenging to absorb for disadvantaged populations, who often lack the resources to adapt to these new conditions. Meanwhile, the effects of gradual climate change are also becoming more visible.
If the current rate of climate change continues, 100 million people in developing countries could be forced into poverty by 2030. Climate science predicts that these people will be displaced because of the erratic climate and extreme weather events. Some cities are even preparing for a “managed retreat” to reduce the risk of relocating. For example, the city of Jakarta in Indonesia, with its population of 10 million, has decided to move its capital to the north to avoid flooding. Many people have been displaced in Indonesia already due to storms and sea-level rise.
In areas with relatively low population density, climate change is causing an increased intensity of development along floodplains, resulting in an unacceptable level of risk. With global warming predicted to continue rapidly, governments must implement adaptation policies to benefit poor people, not just the wealthiest.
In the United States, a recent study published in Nature Climate Change estimates that an increase in the number of floods and severity of floods could cost nearly $41bn by 2050. The cost of flooding could increase even further because more people are likely to live in high-risk areas. As the climate warms, the intensity of storms will increase, and storm surges will contribute to the rising sea levels.