Dr Derick B Wesonga
“It took a split second,” recalls Mutesi (other name withheld for confidentiality). Something in the air triggered her asthma attack. Her lips turned blue (cyanosis) as she was rushed to the emergency unit. Graciously, the team helped her breathe normally. But her sense of safety and stability didn’t snap back so readily. To her, it was a moment of realisation about how the environment and health are intimately linked.
Climate change is among the greatest public health threats of the 21st Century and a defining modifier of the global disease burden. The World Health Organisation (WHO) projects there will be approximately 250,000 deaths annually from climate change worldwide between 2030 and 2050. The direct effects of climate change are obvious and insidious, leading to acute and chronic diseases resulting from increased temperatures, food and water insecurity, air pollution, and vector-borne diseases. The poor and disenfranchised are affected disproportionately by climate change, with conflict and mass migration stemming from hostile environmental conditions.
The largest geophysical global climate change is the steady rise in temperatures worldwide. Global temperature rise is driven primarily by the combustion of fossil fuels and the deposition of greenhouse gases in the atmosphere at a rate that exceeds natural processes. Without immediate mitigation efforts by major industrialised nations, the morbidity from rising temperatures will be difficult to prevent. Children, low-income families, individuals with preexisting conditions, pregnant women, and the elderly are the most susceptible to the health effects of increased heat.
Related to temperature increases are extremes of precipitation and the intensity of storms. Rising temperatures contribute to the spread of vector-borne and water-borne diseases and lead to the growth of fungi and moulds that increase respiratory and asthma-related illnesses. While rainfall increases dramatically in some regions of the world, long-term droughts occur elsewhere.
Climate change is also inextricably linked to ambient air pollution, a leading global risk factor for premature death.
Proposed climate change mitigation policies, particularly policies intended to transition us toward cleaner energy sources in electricity production and transportation, would likely have large air quality benefits. Resulting changes in air quality would substantially affect a range of health outcomes. Breathing polluted air damages the heart, lungs, and other vital organs, contributing to premature deaths. Exposure to ambient air pollution leads to diseases such as stroke, heart disease, lung cancer, asthma, chronic obstructive pulmonary disease, and respiratory infections. The WHO estimates that seven million people die annually from exposure to air pollution, making it the largest global environmental risk factor for premature mortality.
Enlarging refugee camps have high rates of diarrhoeal diseases, measles, acute respiratory infections, malaria and other vector-borne diseases, sexually transmitted infections, malnutrition, and chronic disease complications and mental health disorders due to weather disasters, forced migration, food insecurity, and extreme heat waves. Post-traumatic stress disorder, depression, domestic abuse, general anxiety, and substance abuse have all been associated with climate change in some contexts.
Hospitals and laboratories emit 4.4 percent of the world’s greenhouse gases and are responsible for more than five million tonnes of waste each year.
In conclusion, the earth’s climate is changing rapidly, and the manifestations of these changes are likely to intensify. We can no longer ignore the direct and indirect effects of these changes on human health. The next generation of physicians, academia, policy makers must be better prepared to address the many implications of climate change on the mental and physical health of their patients and society. Physicians can play a crucial role in climate change mitigation and health system adaptation to prepare for emerging health threats. Efforts invested in physician training will benefit their communities—generations of patients—whose health will be impacted by a period of remarkable climate change.
Wesonga is a medical doctor and environment activist
