A stark warning has been issued regarding the world’s remaining carbon budget, revealing that the window to limit global warming to 1.5 degrees Celsius with a 50 percent probability is rapidly closing. A new report from the Global Carbon Project (GCP), a collaboration of international scientists including researchers from Ludwig Maximilian University Munich (LMU) and the Alfred Wegener Institute (AWI), paints a concerning picture of insufficient progress towards climate targets.
The report details a projected rise in global fossil CO2 emissions to 38.1 billion tonnes in 2025, a new record level surpassing 2024’s figures by 1.1 percent. This alarming increase effectively diminishes the remaining timeframe to adhere to the 1.5-degree target to just four years. Achieving a 50 percent chance of limiting warming to 1.7 or 2 degrees Celsius would extend that window to 12 or 25 years respectively – but the current trajectory is decidedly off course.
While the rate of increase in CO2 emissions has slowed in the last decade (averaging 0.3 percent annually compared to 1.9 percent in the previous decade), the effort is demonstrably inadequate to drive emissions towards net-zero in the long term. The report acknowledges some positive developments, notably a slowdown in fossil CO2 emission growth in China and India, attributed to significant investments in renewable energy. A growing number of countries, including the US and EU members, have managed to simultaneously reduce fossil CO2 emissions while experiencing economic growth – a testament to the potential for decoupling economic progress from environmental degradation.
However, the overall picture remains problematic. The report forecasts increases in emissions from all major fossil fuel sources in 2025 – coal (0.8 percent), oil (1 percent) and gas (1.3 percent). Despite a decline in coal combustion emissions within Europe, emissions from oil and gas are projected to rise. The international aviation sector is also contributing to the worsening picture, with a projected increase of 6.8 percent in emissions.
A minor area of positive news lies within emissions from land use, which are anticipated to decline. However, this success demonstrates how targeted environmental policies can yield results, with deforestation rates in the Amazon region falling to their lowest level since 2014.
Importantly, the oceans have absorbed 29 percent of human-caused CO2 emissions over the past decade, acting as the largest natural carbon sink. However, this sink has largely stagnated since 2016, influenced by climate fluctuations and the severe marine heatwaves impacting the northern hemisphere in 2023-2024. Similarly, terrestrial carbon sinks experienced a significant downturn in 2024 due to El Niño conditions, although researchers anticipate a rebound in 2025.
The report also highlights the vulnerability of ecosystems, as demonstrated by the devastating wildfires in 2024. It underscores a critical point: effective climate action and robust ecosystem protection are inextricably linked and urgent, transformative change is required to avert catastrophic consequences. The findings serve as a forceful reminder that current efforts are falling far short of what is needed to secure a sustainable future.
