Climate change is putting pressure on the world’s blood supply, according to a new study published in The Lancet Planetary Health. Fires, hurricanes and floods are hampering donations, blocking transportation and increasing demand, creating imbalances at the very times of greatest need. In the United States, in 2025 alone, the Red Cross has already recorded nearly the same number of donation cancellations as in 2024, with thousands of cancellations related to disasters such as Hurricane Helene or the fires in Los Angeles. As the study states, “These events can disrupt blood donation activities, compromise transport and storage infrastructure, and exacerbate the spread of infectious diseases, thereby affecting both the sufficiency and efficiency of blood supplies.”
In addition, high temperatures are expanding the spread of blood-borne viruses such as dengue, Zika and West Nile, reducing the number of eligible donors. The study authors call for targeted planning, early warning systems and the use of artificial intelligence to monitor infectious outbreaks and predict critical issues.
“For many patients living with urgent medical care needs, crises do not stop with natural disasters,” said Pampee Young, medical director of the American Red Cross. “Rather, in some cases, the stress caused by a disaster can trigger a critical situation for people battling conditions such as sickle cell anemia.”
The study emphasizes that ensuring safe and available blood is a top priority for health systems around the world. An adequate supply is essential for many medical procedures, from surgeries to trauma care, from cancer treatments to chronic disease management. The integrity of safety protocols and supply chains is crucial to preventing transfusion-transmitted infections.
