"The Amazon forest faces a substantial risk of deterioration if the worldwide temperature rise surpasses the critical threshold of 1.5 degrees Celsius"
A new study published in Nature Climate Change has revealed that exceeding the Paris Agreement's 1.5°C warming target could have critical consequences for the Amazon and Siberian forests. The research, conducted by a team of scientists, assessed the health of these forests using two key metrics: net primary productivity and forest cover.
The scientists employed a modelling framework designed to rapidly examine a range of climate outcomes, projecting the impact of various emissions scenarios on forest health. Their findings suggest that large areas of both Amazonian and Siberian forests could experience reduced net primary productivity by 2100 due to the overshoot, compared to a scenario with no overshoot.
In the Amazon, most dieback scenarios occur under hot and dry conditions, according to the authors. Similarly, Siberian forests, part of the broader Arctic permafrost region, face increased risks from climate-induced changes, including thawing permafrost that threatens their stability and carbon storage capacity.
The researchers used hundreds of climate-model simulations to investigate the risks of overshoot for the Amazon and Siberian forests. Across all simulations where global warming in 2100 surpasses 1.5°C, 37 per cent show "some amount of dieback" in the Amazon and Siberian forests. However, the risk increases further in the long term, with "55 per cent of simulations exhibiting dieback by 2300".
The study also highlights the possibility of regional tipping points potentially further amplifying and locking in future forest shifts, even with negative emissions. The greatest uncertainty in this study comes from the spread of climate sensitivities, with the possibility of forests facing harmful impacts even under low emissions scenarios if climate sensitivity is higher than expected.
The maps provided in the study show a comparison of net primary productivity in the Amazon and Siberian forests between a renewable energy (non-overshoot) scenario and a negative emissions (overshoot) scenario in the year 2100. The findings underscore the importance of avoiding even temporary overshoot of the Paris target to minimize devastating climate impacts.
"We can't afford complacency" in addressing climate change and its impact on forests, the study concludes. The authors used the results to identify which future temperature and rainfall conditions result in net forest "dieback" in the Amazon. Additionally, the research finds a change in the composition of Siberian forests, with vegetation shifting from grassy surface types to more trees and shrubs in a process called "woody encroachment".
This study underscores the urgent need for global action to keep warming below 1.5°C and protect these vital global ecosystems.
The new study in Nature Climate Change suggests that exceeding the Paris Agreement's 1.5°C warming target could lead to critical consequences for the Amazon and Siberian forests, impacting their net primary productivity and forest cover. The scientists employed a modelling framework to project the impact of various emissions scenarios on forest health, with large areas of both forests potentially experiencing reduced productivity by 2100.
The researchers found that most dieback scenarios in the Amazon occur under hot and dry conditions, while Siberian forests face increased risks from thawing permafrost due to climate-induced changes. Across all simulations where global warming surpasses 1.5°C in 2100, 37% show "some amount of dieback" in these forests, increasing to 55% by 2300.
The study also suggests the possibility of regional tipping points, further amplifying and locking in future forest shifts. The findings underscore the importance of avoiding even temporary overshoot of the Paris target to minimize devastating climate impacts. Additionally, the research finds a change in the composition of Siberian forests, with vegetation shifting from grassy surface types to more trees and shrubs in a process called "woody encroachment".
This study underscores the urgent need for global action to keep warming below 1.5°C and protect these vital global ecosystems. The transition to renewable energy and reducing carbon emissions are essential steps in mitigating climate change's impact on forests, biodiversity, and health-and-wellness, which are interconnected with environmental-science and SDG goals. Ignoring climate change could have serious implications for medical-conditions and health-and-wellness, as well as contributing to ongoing climate change.
