Wildfires, logging make World Heritage forests carbon emitters, study shows

Sacramento Metropolitan firefighter Clint Alexander monitors the Rim Fire near Camp Mather, California. The fire burned 160,980 acres on the northwest side of Yosemite National Park. Photo: Max Whittaker/Reuters

Oliver Griffin

October 29 2021 07:28 AM

Some of the world’s most protected forests are emitting more carbon than they absorb, driven by wildfires and activities such as logging , a new report has shown .

At least 10 forests designated World Heritage sites – including Yosemite National Park in the US – have been net carbon emitters over the past two decades, the report said.

“That even some of the best-protected forests such as those in World Heritage sites can contribute to climate change is alarming and brings to light evidence of the severity of this climate emergency,” said Tales Carvalho Resende, report co-author and project officer for Unesco.

Forests are vital for curbing climate change due to their ability to work as so-called carbon sinks. Trees and other plants absorb carbon dioxide and emit oxygen, removing greenhouse gases from the atmosphere.

All 257 forests together do act as a net carbon sink, according to the research, which analysed a period from 2001 to 2020. Still, human activities including logging are hindering their ability to capture and store more carbon than they emit.

Unesco investigators and researchers from advocacy groups the World Resources Institute and the International Union for Conservation of Nature combined satellite data with on-site monitoring and found that, together, the heritage sites saw net absorption of 190 million tons of CO2 annually over the 20-year period.

The findings drew on data that mapped greenhouse gas emissions and absorption by forests globally. The researchers used this and monitoring of the heritage sites to understand what is putting forests at risk.

“I would expect all of them to be removing carbon from the atmosphere, and not to be sources of carbon,” said Carlos Sanquetta, a forestry engineering professor at the University of Parana in Brazil.

While only 10 of the Unesco forests were found to have been carbon emitters, the report said other sites also showed clear upward trajectories in emissions.