The emissions data released Thursday contains some glimmers of good news. The yearly amount of carbon dioxide released by deforestation and changes in land use appears to have declined over the past two decades, to around 3.9 billion tons in 2022. Once that is included, humanity’s total carbon dioxide emissions from fossil fuels and land use have stayed roughly flat since 2015.
Part of the story, researchers said, is that forests appear to be expanding or recovering in many regions, such as on abandoned farmland in Europe. As those trees grow, they absorb carbon dioxide from the atmosphere. That has helped offset a fraction of the emissions produced by deforestation, which remains stubbornly high in places like Brazil, Indonesia and the Democratic Republic of Congo.
Still, there are large uncertainties around land use emissions, and it is too early to say whether this trend is robust, said Julia Pongratz, a geographer at the University of Munich, who worked on the report. While it’s relatively straightforward to count up how much oil, gas and coal countries are burning, it’s much harder to estimate how much carbon dioxide is actually released when farmers clear away rainforests or set fire to peat lands.
Under the Paris agreement in 2015, world leaders agreed to limit total global warming to “well below” 2 degrees Celsius (3.6 degrees Fahrenheit), compared with preindustrial levels, and to make a strong effort to hold warming to 1.5 degrees Celsius. The world has already warmed 1.1 degrees Celsius, and scientists warn that with every additional fraction of a degree, tens of millions more people worldwide would be exposed to life-threatening heat waves, food and water scarcity.
The new data shows that time is running out to reach those targets. If emissions were to merely stay flat at 2022 levels, the researchers found, the world would likely put enough carbon into the atmosphere to exceed the 1.5 degree Celsius threshold within nine years, and exceed the 2-degree Celsius threshold within 30 years.
“On our current course, without massive cuts in emissions, we’re going to exhaust our remaining carbon budget very, very quickly,” said Pierre Friedlingstein, a climate scientist at the University of Exeter, who helped led the research.