The world is on track to deplete its remaining carbon budget within six years, pushing global temperatures beyond the 1.5C threshold, a major international study has found.
The latest annual update by the Global Carbon Budget, which tracks where carbon emissions end up in the Earth's system, found that time is running out to prevent dangerous temperature rises.
“It’s very likely we will exceed the 1.5C limit if emissions continue at the current rate,” said French climate scientist Philippe Ciais, one of more than 120 scientists who contributed to the report, in an interview with RFI.
Current trajectories show there's a 50 percent chance that 1.5C will be breached by the end of the decade.
Released Wednesday, the study includes emissions from both fossil fuel burning and land-use changes, such as deforestation, which releases carbon stored in forests.
It projects that fossil fuel emissions will reach 37.4 billion tonnes in 2024 – a 0.8 percent increase from 2023.
The World Meteorological Organisation (WMO) last month flagged record greenhouse gas emissions in 2023, warning this will commit the world to rising temperatures for decades to come.
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Rising fossil fuels
While deforestation-related emissions have declined over the past 20 years, those from fossil fuels continue to rise. Although the rate of increase has slowed since the 2000s, there is still no sign of a sustained decline, Ciais explained.
Some regions have shown progress in reducing emissions. Europe has seen decreases since the late 1980s or early 1990s, and the United States since 2005. However, India's emissions are rising sharply, while China saw nearly 5 percent growth in 2023 due to increased coal use.
Natural carbon sinks – forests and oceans that absorb carbon dioxide – continue to play a vital role but face mounting pressures. Oceans absorb carbon dioxide consistently, but land-based sinks are more vulnerable to climate impacts.
"When we have a warmer or drier climate – for example, there was a very large drought in the Amazon in 2023 – they can suddenly start releasing carbon," Ciais said.
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Forests under pressure
The report attributes around 60 percent of global deforestation-related carbon emissions to three main regions, each affected by unique pressures.
“In Brazil, it’s mainly illegal deforestation linked to the expansion of livestock farming, which is an extremely important and very centralised industry,” Ciais said.
In Africa, deforestation is largely driven by subsistence farming and the use of wood for energy.
In Southeast Asia, however, much of the forest loss comes from large-scale plantations, such as oil palm and rubber, which store less carbon than the native tropical forests they replace.
The study emphasises that natural forests are significantly better at capturing and storing carbon than planted monocultures.
“In a hectare of primary forest, there are more than 150 species living together. It’s the entire plant ecosystem that absorbs CO2, much more than monocultures,” Ciais said, explaining the biodiversity and density that make natural forests so effective.
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Threshold breach
The findings come as the European Union's Copernicus Climate Change Service reports that 2024 will be the first year when global temperatures exceed the 1.5 degrees Celsius warming threshold set by the Paris Agreement.
The agency says 2024 is also virtually certain to be the warmest year on record.
For 16 consecutive months from June 2023 to September 2024, global mean temperatures exceeded previous records by a wide margin, according to the WMO.
Even if emissions were rapidly reduced to net zero, the current temperature levels would persist for several decades due to the long life of CO2 in the atmosphere, scientists say.
