Deforested areas of the Amazon Basin have a limited ability to recover due to recent changes in climate, according to a study published today.
Limited growth in a drier climate has restricted the amount of carbon that new trees can lock away from the atmosphere, reducing their ability to counteract the effects of global warming.
The research was carried out by NCEO and University of Edinburgh’s Professor Mat Williams and Dr Jeff Exbrayat and researchers at Nanjing University of Information Science and Technology in China. They found that forests replanted today would only likely recapture two-thirds of the carbon they have lost to the atmosphere in the past 20 years through deforestation and climate change.
Their findings could inform conservation strategies, including goals set out in the Paris Agreement, in which many countries have committed to reforestation.
The scientists say that while replanting forests remains an effective way to counter the effects of climate change, even this may prove challenging.
The researchers used artificial intelligence to combine satellite data and climate records to reconstruct annual maps of forest change due to deforestation and climate change in the Amazon Basin. Over two decades to 2012, the overall amount of carbon lost to deforestation and climate change combined was 2.2 billion tonnes. This is equivalent to about 10 years’ worth of fossil fuel emissions from countries spanning the Amazon Basin.
The study is the first to differentiate between the impact of human activity in the Amazon – such as deforestation or changes in land use – and the impact of climate change, to quantify the carbon-storing potential of new forests.
Deforestation Scars in Amazon Basin seen from Space (Contains modified Copernicus Sentinel 2a data 2016 (NCEO CAF) (17 July)
Further studies of tropical regions involving new satellites should enable scientists to work with affected countries to better conserve and manage their forests.
Professor Mathew Williams, of the University of Edinburgh’s School of GeoSciences, said: “Owing to the impact of climate change, replanted and recovering forests may not grow to the sizes found in the undisturbed Amazon.”
Dr Jean-François Exbrayat, who is also based at the University of Edinburgh, led the study. He said: “Technological advances are enabling us to build a clearer picture of the resilience of the Amazon and other tropical forests, which will help develop strategies to safeguard these environments.”
The research, published today in Scientific Reports, was funded by the Natural Environment Research Council’s NCEO.
NCEO scientists will share their research with the public at UnEarthed. Explore the world at your feet, a free interactive showcase of environmental science at Our Dynamic Earth, Edinburgh, from 17-19 November.