The world has barely recovered from the devastation caused by the Covid-19 pandemic. Now scientists are warning that the next pandemic will be offset by climate change. And policymakers must take decisive action to protect the most vulnerable communities. 

Over 100 scientists from around the world are part of the Climate Amplified Diseases and Epidemics consortium or CLIMADE. In a report released at the recent United Nations conference on climate change, COP28, the group highlights the intersection between climate change and infectious diseases. 

“The main worry is that climate change has a potential to aggravate over 50% of known human pathogens [viruses, bacteria, fungi and parasites],” says Professor Tulio de Oliveira, director at  the Centre for Epidemic Response and Innovation (CERI) at Stellenbosch University and one of the lead authors of the report. He was speaking at a side event that was hosted by the government of Mozambique, a country that has experienced nearly 20 multiple consecutive cyclones between 2019 and 2023.

The report highlights three climate hazards that have an impact on the spread of disease: increasing temperatures, extreme weather events, and climate migration. Based on this, scientists are calling on policymakers to take the evidence-based report seriously and act before the next pandemic hits.

Climate change and disease

The first climate hazard flagged in the CLIMADE report is increasing temperatures. Some disease vectors like mosquitoes, rodents and ticks thrive in warmer conditions. Rising temperatures means that vectors like mosquitoes can survive in geographic areas that were previously inhospitable. This, in turn, means that mosquito-borne diseases like malaria and dengue fever will spread in new areas, infecting new populations. 

The second hazard highlighted in the report is extreme weather events like droughts and floods. These events, like cyclones in Mozambique, leave stagnant flood water which are fertile breeding ground for mosquitoes and increase the spread of disease. Extreme weather events also destroy basic infrastructure like roads and homes. This increases the risks of waterborne diseases like cholera. 

The final hazard is climate migration. Now more than ever people are being displaced because of extreme weather events. Communities hit by floods often have to find new places to settle. Droughts and crop failures have led to food insecurity, pushing people to move in search of  more social and economic stability. Pastoral communities often migrant along with their livestock. The movement of people – and animals – can drive the spread of diseases. 

Call to action 

The Mozambican Director General of the Instituto Nacional de Saude (INS) or National Institute of Health, Dr Erduardo Samo Gudo says that solutions are needed to help countries that are highly vulnerable and affected by climate change can deal with the impact.

This year Mozambique saw its most catastrophic cyclone by far. Cyclone Freddy hit 10 of the country’s 11 provinces, affecting 1,18 million people where 192,000 were displaced and 183 people died.

Samo says the health system has become more vulnerable and unable to recover because of the frequency of the tropical cyclones that have hit the country in the last three years. 

“We [Mozambique] suffer more because we have more social and economic vulnerability. We cannot do it alone, we need external support and investment to cope with the impact of climate change,” he explains. 

A One Health approach 

“The report is important in showing how international and regional collaboration in Africa can make a change in science to understand the drivers of disease in the context of climate change,” said the co-lead for Animal and Human Health Programme at the International Livestock Research Institute (ILRI), Dr Hung Nguyen-Viet.

Nguyen-Viet is also lead in the One Health initiative of the Consortium of International Agricultural Research (CGIAR). The One Health approach highlights the link between human, animal, and environmental health.

This approach will be important to control current diseases and also prevent future outbreaks, he says. – Health-e News 

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