Global atmospheric carbon dioxide (CO₂) levels surged faster in 2024 than in any year since records began a stark warning that the Amazon rainforest, once a powerful carbon sink, is faltering under pressure.
A new satellite analysis by researchers from the University of Edinburgh reveals that the Amazon absorbed far less CO₂ in 2024, contributing to the record global rise of 3.73 parts per million (ppm) well above the long-term average. This finding comes from NASA’s Orbiting Carbon Observatory (OCO-2), a satellite launched in 2014 that has transformed how scientists monitor CO₂ across the planet. Yet, despite being fully operational and capable of running until 2040, OCO-2 now faces shutdown due to proposed NASA budget cuts.
Since the 1950s, CO₂ concentrations have climbed from 315 ppm to over 420 ppm today. But what’s most alarming is the speed of this increase. “Every extra ppm represents roughly 2 billion tonnes of carbon about four times the combined mass of every human alive,” researchers noted.
The OCO-2 satellite revealed that in 2023 and 2024, tropical regions particularly the Amazon experienced sharp drops in carbon absorption. Extreme drought and rising temperatures have weakened the forest ability to act as a carbon sponge. Data also show similar slowdowns in parts of southern Africa and Southeast Asia, while modest increases in carbon absorption were seen over North America and Europe.
According to Dr. Liang Feng and Professor Paul Palmer from the University of Edinburgh, the 2024 pattern resembles past El Niño years, such as 2015–16, but the recent El Niño was relatively weak. Instead, prolonged drought in the Amazon appears to have magnified the crisis. Rivers like the Tapajós have dried to record lows, leaving boats stranded and ecosystems severely stressed.
Scientists warn that this may signal a long-term decline in the Amazon’s resilience. If forests can no longer absorb enough CO₂, a larger share of human emissions will stay trapped in the atmosphere, making it harder to meet global climate targets.
Experts stress the need for continued satellite monitoring to understand these shifts. “We wouldn’t be blind without OCO-2,” the authors said, “but we’d be seeing far less clearly.” Losing it, they warn, would cripple our ability to track the carbon cycle in real time just as the planet largest rainforest sends its clearest warning yet.
The study urges urgent investment in both ground research across tropical ecosystems and long-term satellite observation. As climate stresses intensify, protecting tools like OCO-2 may be just as crucial as protecting the forests themselves.