For the first time since the pandemic, carbon emissions from fossil fuels could fall this year

The annual Global Carbon Budget reports provide a rigorous and detailed account of the state of global carbon dioxide (CO₂) emissions and their sinks. The large group of institutions and scientists responsible for compiling these reports presents, each year to coincide with the climate summits (COP), a continuously updated analysis of CO₂ sources and sinks. This enables an assessment of the varying impact of environmental policies on controlling atmospheric CO₂ concentrations – the root cause of current climate change.

This year’s report comprehensively documents the positive development of a decoupling between CO₂ emissions and economic growth, contrary to what had been the case when the climate summits first began. Emissions are currently falling whilst the economy is growing. The main reason for this decoupling lies in the rapid expansion of clean and renewable technologies for electricity generation (primarily solar and wind) and of electric vehicles. However – and this is the bad news – the rise in global energy demand is not yet being offset by the roll-out of renewable sources for electricity generation and electric mobility; therefore, the roll-out of clean energy must be accelerated in order to control CO₂ emissions and, consequently, the rise in its concentration in the atmosphere, which is the cause of climate change. At the current rate of CO₂ emissions, we will reach the 1.5 °C temperature rise stipulated in the Paris Agreement in less than four years. The report emphasises that the relatively favourable figures for fossil-fuel-based CO₂ emissions this year are, in part, influenced by geopolitical events that have significantly reduced emissions; consequently, caution is required when quantifying the observed trends.

In short, this annual report, together with previous ones, enables the monitoring – essential for governments to design their climate strategies – of the efforts made to reduce CO₂ emissions and the effectiveness of carbon sinks in absorbing carbon. Although slightly positive trends are evident, the collective global effort to reduce emissions should be stepped up to comply with the global temperature rise limits set out in the Paris Agreement.

This annual exercise, which has been systematically assessing trends in fossil emissions and CO₂ sinks for over two decades, is of great value as it enables us to determine whether the trends in net contributions of this climate forcing factor to the atmosphere are rising or falling.

The projected decline in fossil CO₂ emissions in 2026 (-0.4 per cent) is an encouraging sign, although to determine whether this represents a trend reversal or is due, in part, to a temporary factor, decreases will need to be observed over several years. The most notable aspect of the report is precisely this underlying trend, in which several dozen countries are reducing emissions whilst their economies are growing (there were far fewer such countries a decade ago). Even so, the authors themselves caution that a decline in a single year does not constitute a peak and that atmospheric CO₂ levels continue to rise.

The main limitation is that the figure for 2026 is a projection based on partial data and carries a wide margin of error; consequently, a slight increase cannot be ruled out once the 2026 data are finalised. There also remains a high degree of uncertainty regarding emissions from deforestation and the ocean’s actual absorption capacity. What does appear to be confirmed by the historical data series is that climate change is already weakening biological sinks and that the powerful El Niño event of 2026 could cause the terrestrial sink to collapse again in 2027, as it did in 2023–2024.

The message is clear: the carbon budget for 1.5 °C is almost exhausted, and CO₂ capture is now doing less and less to offset annual emissions.