A fire in the Brazilian Amazon. Carl de Souza / AFP / Getty Images

As the planet heats up, tundras are thawing, wetlands are fermenting, and forests are succumbing to larger and more frequent wildfires. The breakdown of these natural systems is unleashing huge volumes of emissions, further intensifying warming from the burning of fossil fuels. According to new research, such feedback loops could amplify human-driven warming by 20 to 30 percent.

Even if humans reach net zero emissions later this century, feedbacks would add another 0.2 degrees C of warming, according to the modeling study , published this week in Environmental Research Letters.…