Opinion | ‘The Last of Us’ Is Right. Our Warming Planet Is a Petri Dish.

Counterintuitively, so can drought. In the American Southwest, long periods without rain have dried out the earth, leading to dust storms. Reported cases of Valley fever, a once-rare respiratory illness caused by soil-borne fungal spores, have soared nearly tenfold since 1998; the fungus has also spread to new regions, including Washington State.

A warming planet is creating more vulnerability in humans, too. Reduced crop yields, for example, lead to malnutrition, while heat stress causes kidney disease. At the same time, deforestation, inadequate safety measures on farms and commercial wildlife trade increase the risk of so-called spillovers, where viruses like Ebola jump from animals to people. Fungi, nature’s savviest opportunists, will use these disturbances to their advantage. We saw this in the 1980s as fungal infections surged alongside H.I.V., a virus that emerged from spillover. We also saw it more recently when a unique fungal disease affected thousands of people in India who had received immune-suppressing steroids as part of their treatment for Covid-19.

Last October, the World Health Organization created a list of “fungal priority pathogens” for the first time. “Fungal pathogens are a major threat to public health,” the group wrote. This was an important symbolic gesture, but it does not give doctors what they need: better tools to fight these infections. There are no approved vaccines. Globally, many countries lack the capacity to diagnose certain common fungal diseases. Even in New York City, where I treat patients, it can take weeks for some to receive a diagnosis for fungal infections. Worse yet, many fungal pathogens already are resistant to the few antifungal drugs we do have available.

In part, this is a technical challenge: It’s difficult to develop antifungals that don’t also destroy our cells. But we cannot develop cures if we don’t try — and right now, fungal research output is abysmal. For example, cryptococcal meningitis, a fungal infection, kills more people than bacterial meningitis caused by Neisseria meningitidis, yet the latter receives over three times as much research funding.

Fungal pathogens simply haven’t been on government funders’ radar — they receive just 1.5 percent of all research funding for infectious disease research. Likewise, pharmaceutical companies have little incentive to invest in research and development, because the potential profit is limited.