Tropical forests may be warming to a point where plant photosynthesis fails, study warns

LOS ANGELES — Teeming with life and stretching across multiple continents, tropical forests are often called the “lungs of the planet” because of their ability to suck up climate-warming carbon dioxide and exhale oxygen — a process known as photosynthesis.

But even as these critical ecosystems work with Earth’s oceans to help scrub CO2 from the atmosphere and give us air to breathe, tropical forests have long faced growing threats from fires, poaching and deforestation.

Now, new research suggests that humanity’s unchecked burning of fossil fuels may pose an entirely new danger.

In a study published recently in the journal Nature, scientists concluded that tropical forests could be drawing closer to the temperature threshold where leaves lose the ability to create life-sustaining energy by combining CO2, water and sunlight.

“We have known for