Message from Elisha
The United Nations General Assembly is taking place as I write this month’s message. Though the formal agenda features only one health-focused High Level Meeting (the Antimicrobial Resistance, or AMR HLM, on September 26), the topic will be inescapable throughout the convening. The impacts of climate change will also be at the forefront of the discussions, and the link between increasing temperatures and higher disease risks is more evident every day.
AMR and Climate
According to a landmark study published in The Lancet in 2022, approximately 1.27 million deaths were directly attributed to drug-resistant bacterial infections in 2019. Additionally, AMR was associated with an estimated 4.95 million deaths globally in that year, meaning those deaths involved infections that were complicated by antimicrobial resistance, though not directly caused by it.
As AMR continues to spread, the number of people affected by resistant infections each year is expected to rise, a problem made even more severe by climate change. Higher temperatures increase both the rate of bacterial growth and the rate of the spread of antibiotic-resistant genes between microorganisms. Extreme weather and rising temperatures encourage the spread of drug-resistant infections, and changing weather patterns help bacteria to thrive. In addition, floods, droughts, hurricanes, and wildfires reduce access to clean water, leading to a vicious cycle of increased infections that require more people to take antibiotics, thus creating greater opportunity for antibiotic resistance.
Mosquito-Borne Diseases
Similar to its impact on AMR, climate change is also proving to be instrumental in the spread of mosquito-borne disease. At the moment, several of these diseases are causing alarm. Many models show that malaria will surge with ongoing climate change. The journal Nature reported that locally recorded cases of West Nile virus in Europe in 2024 have surpassed 2023 cases. The problem is certainly not isolated to that region of the world. According to the U.S. Centers for Disease Control, global incidence of dengue in 2024 has been the highest on record. Outbreaks of Oropouche virus disease continue unabated in South America and Cuba, and they are spreading to new, previously non-endemic areas. And, multiple cases of eastern equine encephalitis have been reported in U.S. states, including Massachusetts, Michigan, and New York.
Climate Change and Pandemics
Climate change also increases pandemic risk. Warming and land-use change, especially deforestation, contribute to interspecies contact that increases the chance for pathogens to spillover from animals to people—the intersection at which most infectious diseases emerge. Examples of infectious diseases with such zoonotic origins include HIV, Ebola virus disease, and monkeypox. [Sidenote: for more information on both AMR, climate, and water, sanitation, and hygiene, I encourage you to refer back to GHC’s most recent Global Health Briefing Book.]
As food and water become scarce in regions of the world due to climate change, conflict and migration further fuel the spread of disease. The conflicts in Gaza and Ukraine are painful examples of how overcrowded refugee camps make the spread of disease far too efficient. In addition, disrupted access to healthcare services makes diseases harder to treat and prevent. And, as people abandon communities that are no longer habitable, they may be exposed to pathogens in their new locations to which they do not have immunity.
Time is of the Essence
These very issues—AMR, climate, and health—are also prominently featured on the agendas of the upcoming G20 and UN Climate Change Conference. It is encouraging to see these critical topics rising to the forefront of global policy discussions. However, the urgency cannot be overstated. We are quickly approaching the point where time to devise pragmatic, well-resourced solutions is running out. The moment for ambitious, yet actionable, steps to mitigate these interconnected global crises is now, before the opportunity to make a meaningful impact slips through our fingers.
We will be watching with interest as the discussions take place this week in New York. And we will be ready to provide context for the community and turn talk into accountable action when the 79th session of UNGA comes to a close.