Climate change, not El Nino, played a predominant role in the unprecedented drought that afflicted the Amazon rainforest last year, causing rivers to dry up, impacting river communities, and leading to the deaths of endangered dolphins, according to a report from World Weather Attribution, an international network of scientists.
The study, released on Wednesday, revealed that human-induced global warming was the primary driver behind the extreme drought, making it 30 times more likely, with higher temperatures being the major factor.
The research focused on events from June to November in the previous year, highlighting that global warming, attributed to fossil fuel combustion, reduced rainfall and intensified drought conditions by increasing evaporation from plants and soil.
While both climate change and El Nino contributed roughly equally to reduced rainfall, elevated global temperatures emerged as the principal cause of the severe drought.
All nine Amazon rainforest countries, including Brazil, Colombia, Venezuela, and Peru, felt the impact of the drought, which is expected to worsen after the rainy season ends in May.
The consequences have been devastating, with communities facing challenges in accessing food, medicine, and other essentials. Many people resorted to dragging boats over dried-up sections of the Amazon River.
Crops withered, fish disappeared, and low river levels made travel impossible, prompting long lines on riverbanks for relief supplies.
The city of Manaus, the largest in the region, experienced months of choking on wildfire smoke due to the drought.
The study also highlighted the ecological impact, with researchers in Brazil estimating that at least 178 endangered pink and grey river dolphins perished, and thousands of fish died due to low oxygen levels in tributaries.
The report underscores the vulnerability of the Amazon rainforest and its critical role in addressing climate change by absorbing vast amounts of greenhouse gases. The unprecedented scope of the drought, affecting the entire Amazon basin, raises concerns about the health of the forest.
Researchers warn that continued warming could lead to more frequent occurrences of the combination of low rainfall and high temperatures, potentially pushing the Amazon towards a point of no return, where it transforms from a lush rainforest into a dried-out biome.
With the planet experiencing its hottest year on record, the study adds urgency to global efforts to limit temperature increases. The world is approaching the 1.5 degrees Celsius (2.7 degrees Fahrenheit) threshold that nations aimed to stay within to avert the worst consequences of climate change, including deadly heat, rising seas, flooding, and wildfires.
Study co-author Friederike Otto, a climate scientist at the Imperial College of London, emphasized the need to address climate change to prevent more frequent and severe events like the Amazon drought.