More than 58% of human diseases have worsened due to climate change, according to a new study.
The groundbreaking research, published Monday in Nature Climate Change, was conducted by researchers at the University of Hawaii at Mamoa, who conducted a systematic search for real-life examples of the impact of ten climate hazards made worse by greenhouse gas emissions on human diseases.
These include warming, drought, heat waves, wildfires, extreme rainfall, floods, storms, sea level rise, biogeochemical change and land cover change.
Analyzing more than 70,000 scientific papers to find examples of direct links between known diseases and climate change, scientists found that all extreme weather events made more common and more severe by global warming had an influence on viral diseases , bacteria, animals and fungi. and plants
Of the 375 diseases analyzed, 218 were affected by climate change.
The weather brings the dangers closer
Specifically, the researchers found that the dangers related to climate change bring pathogens closer to people, with warmer temperatures and more humid environments, associated with increased precipitation, favoring the proliferation of mosquitoes, ticks, fleas, birds and mammals responsible for the spread of various viruses and bacteria such as dengue fever, plague, Lyme disease and malaria.
Mosquito populations, in particular, have found a breeding ground after floods and storms, leading in turn to an increase in the pathogens they transmit, including West Nile fever and yellow fever.
But climate change is also bringing people closer to pathogens.
As extreme weather events lead to the displacement and forced migration of thousands of people in some of the most vulnerable parts of the world, contact between humans and pathogens is increasing.
Researchers have linked heat waves to the increased spread of water-borne diseases such as Vibrio (infections caused by bacteria) and gastroenteritis, while storms, floods and rising sea levels they were linked to the spread of cholera, pneumonia, typhoid fever, hepatitis and respiratory diseases. skin diseases, among others.
Our weaker immune systems
Pathogens themselves are getting stronger to adapt to climate change, while our bodies’ immune response has weakened due to the added stress of dangerous conditions, unsafe living situations and uncertain access to healthcare that people experience after an extreme weather event.
“Given the extensive and widespread consequences of the COVID-19 pandemic, it was truly frightening to discover the massive vulnerability of health as a result of greenhouse gas emissions,” said Camilo Mora, professor of geography at the Faculty of Social Sciences (CSS) and leader. author of the study, said in a statement.
“There are too many diseases and transmission routes for us to think we can actually adapt to climate change. It highlights the urgent need to reduce greenhouse gas emissions globally.”
But there is also some positive news that came to light in the report.
Humans are running out of time to adapt
Although the vast majority of diseases have worsened due to climate change-related extreme events, some have improved. Those viruses and pathogens that cannot survive warmer temperatures actually declined.
But that hardly balances how much worse diseases are due to the way greenhouse gas emissions affect our planet’s climate. It is unlikely that humans will be able to adapt in time to deal with these stronger and more widespread diseases, the report’s authors suggest.
“With climate change influencing more than 1,000 transmission pathways like these and climate hazards increasing globally, we concluded that expecting societies to successfully adapt to all of them is not a realistic option,” they write the authors of the study in an article published in The Conversation.
“The world will need to reduce greenhouse gas emissions that are driving climate change to reduce these risks.”