Malaria Cases Are Spiking on a Warmer, Wetter World

The World Health Organization’s annual malaria report, released Thursday, for the first time includes a chapter “focused on the intersection between climate change and malaria” — and finds that climate change was a factor in a global increase in the disease. There were an estimated 249 million malaria cases in 2022, a five million increase over the previous year. Most of the new cases were concentrated in Pakistan, Ethiopia, Nigeria, Papua New Guinea, and Uganda.

The reasons for the surge seem to be manifold. Across sub-saharan Africa, the Anopheles mosquito, which transmits the disease, is expanding its range as the region warms. Flooding can also leave behind stagnant pools of standing water, which leads to a boom in mosquito numbers, as followed Pakistan’s catastrophic floods in 2022. And as people are displaced by such disasters, those without malarial immunity may settle in areas prone to the disease. In many cases they also live in tents or refugee centers, without simple yet crucial protections such as mosquito nets.

As is so often the case with climate change, the problems are at once immense — increasing heat in Subsaharan Africa and South Asia — and practical — not enough nets. “It is crucial to recognize the multitude of threats that impede our response efforts,” said Matshidiso Moeti, the World Health Organization’s Regional Director for Africa. “Climate variability poses a substantial risk, but we must also contend with challenges such as limited healthcare access, [and] ongoing conflicts and emergencies ... we need a concerted effort to tackle these diverse threats.”