Washington, Jul 27 (IANS): An international team of scientists, including from NASA, have created a tropical rainforest vulnerability index which shows how the world's rainforests are responding to warming climate and deforestation.

The index was developed by a team of scientists and conservationists who were convened by the National Geographic Society in 2019. It is based on multiple satellite observations and ground-based data from 1982 through 2018, such as Landsat and the Global Precipitation Measurement mission, covering climate conditions, land use, and forest characteristics.

The index shows that the world's three major rainforest areas -- Amazon Basin in South America, Congo Basin in Africa and Asian rainforests face two main categories of threats: the warming and drying climate, and the consequences of human land use such as deforestation and fragmentation from encroaching roads, agricultural fields, and logging.

It showed that these diverse ecosystems have different degrees of susceptibility to these threats.

The Amazon Basin in South America is extremely vulnerable to both climate change and changes in human land use. The Congo Basin in Africa is undergoing the same warming and drying trends as the Amazon but is more resilient. Most Asian rainforests appear to be suffering more from changes in land use than from the changing climate.

"Rainforests are perhaps the most endangered habitat on Earth -- the canary in the climate-change coal mine," said lead author Sassan Saatchi, scientist at NASA's Jet Propulsion Laboratory in Southern California. The study has been published in the journal OneEarth.

These three diverse ecosystems are home to more than half of the planet's life forms and contain more than half of all the carbon in land vegetation. They serve as a natural brake on the rise of carbon dioxide in the atmosphere from fossil fuel burning because they "breathe in" carbon dioxide and store carbon as they grow.

But in the last century, 15 to 20 per cent of rainforests have been cut down, and another 10 per cent have been degraded. Today's warmer climate, which has led to increasingly frequent and widespread forest fires, is limiting the forests' capacity to absorb carbon dioxide as they grow while also increasing the rate at which forests release carbon to the atmosphere as they decay or burn.

The tropical rainforest vulnerability index will help scientists and policy makers planning for conservation and forest restoration activities.