At COP27 Scientists Warn Outbreaks of Infectious Diseases likely to Increase due to Climate Change

By Charles Ogallo

Scientists are now calling on policymakers to build climate resilience and environmental sustainability into healthcare systems that reflect the uncertainties of climate change impacts and development choices, and their varied effects on humans, animals, plants and ecosystems.

They say compounding risks due to climate change are adversely impacting human, animal and environmental health.

The risks have the potential to slow advances made in population health over the last decades and disrupt functioning health systems across the globe, according to new report launched Thursday November 10, by leading scientists during UN Climate Change in Sharma el Sheikh, Egypt,

The scientists challenged COP27 participants to “Consider the current cost of climate inaction on human, animal and environmental health systems and re-examine budgets and financial incentives to ensure adequate investment in prevention and addressing vulnerabilities”

The 10 New Insights in Climate Science Report shows that Infectious diseases, especially waterborne and vector-borne diseases, as evidenced by increased childhood diarrhoeal disease being observed in some regions during extreme weather events are likely to increase.

”In addition to temperature-related changes in geographic range, large-scale outbreaks of infectious disease can affect local and global health from cascading pathways involving weather and climate events, population movement, land-use changes, urbanization, global trade and other drivers” says the report.

Climate change has been described by the World Health Organization (WHO) as the single biggest health threat facing humanity and its already responsible for 37% of heat-related deaths globally with the burden likely exacerbated by recent 2022 heatwaves that exceeded temperature records.

Heat exposure has also resulted in adverse reproductive outcomes such as preterm birth, low birthweight, stillbirth and lower sperm production.

The report also shows that an increase in cross-species viral transmission risk, and zoonotic virus spillover and spread in humans is more likely, especially at high elevations, in biodiversity hotspots, and in areas of high human population density in Asia and Africa.

However, significant numbers of lives can be protected by investing in early warning systems (relevant to extreme weather events, microbial transmission, and disease outbreaks and other health risks such as respiratory distress or toxicity), which should include monitoring and evaluation, according to the report.

To address the growing climate challenge, the report says health systems need to become more resilient, addressing inequities to better manage complex and compounding hazards in a systems-based manner.

It further recommended for immediate remedies from governments to improve understanding of how climate change is causing injuries, illnesses and deaths today to ensure mitigation and adaptation strategies take a multi-sectoral approach with health as a central motivation.

Other measures proposed include an expanded statistical monitoring related to health to help countries sufficiently track impacts on human, animal and environmental health (one health approach) and document progress towards health protection and resilience.

Governments also need to enhance advocacy to improved microbial and disease surveillance, including from known, novel and antimicrobial-resistant pathogens as well as Improved knowledge about the benefits of disaster preparedness and adaptation options that address inequities.

The report launched by the international networks Future Earth, The Earth League and World Climate Research Programme (WCRP) further indicates that over 3 billion people will inhabit ‘vulnerability hotspots’ - areas with the highest susceptibility to being adversely affected by climate-driven hazards - by 2050, double what it is today. 

According to global assessments of vulnerability that combine socioeconomic factors alongside climate hazard risk, an estimated 1.6 billion people live in regions that are in the highest categories of vulnerability, where populations are predicted to double by 2050.

Regional hotspots are clustered in Central America, Asia, the Middle East and several regions of Africa: the Sahel, Central and East Africa.

In the most vulnerable countries, mortality from floods, drought and storms is 15 times higher than in the least-vulnerable countries, according to the scientific report.