Satellite data disputes mapped forest area, mismatch could complicate climate efforts: Study

New Delhi, Jan 14 (PTI) Maps derived from global forest datasets that are based on satellite images concurred on a "forest" location only 26 per cent of the time. This mismatch can undermine efforts aimed at tackling climate change, biodiversity loss and poverty for which forest maps are crucial, according to a new study.

Researchers including those from the US' University of Notre Dame said estimates for metrics, such as amount of carbon stored in forests or number of people living in poverty near forests can vary, sometimes by a factor of 10.

The mismatch can introduce substantial uncertainty in tackling climate change, biodiversity loss and poverty for which forest maps are crucial, they added.

"Forests are essential to tackling the triple crises of climate change, biodiversity loss, and poverty," the authors wrote in the study published in the journal One Earth.

"A variety of global forest datasets based on satellite imagery now exist. However, our research reveals that maps derived from these datasets often disagree on what counts as 'forest', thereby introducing substantial uncertainty into these global efforts," they said.

"Ten global forest datasets agreed on only 26 per cent of mapped forest area," the team wrote.

Co-author Daniel C. Miller, associate professor at the University of Notre Dame's school of global affairs, said, "When land is viewed from the sky, it's difficult to know at a global scale whether something is a forest or not. Some might consider a small patch of trees to be a forest, but for others only a large, dense area of trees will count." Three case studies -- Kenya's forest carbon, forest-poverty mapping in India, biodiversity habitat in Brazil -- were analysed to show how the digital maps affect human lives and global policy challenges.

For example, in India, the number of people estimated to be living in poverty near forests in 2016 fluctuated from 23 million to 252 million, depending solely on which map was used, the researchers said.

Identifying people affected by forest policy decisions is critical for meeting Sustainable Development Goals (SDGs), they said.

Miller said future work should integrate hybrid data by combining on-the-ground views with satellite data.

"By bridging the gap between satellite technology and on-the-ground reality, we can provide more accurate, inclusive data that truly supports both the planet and the people who protect it," he said. PTI KRS NB NB