Carbon dioxide (CO₂) emissions generated by fossil fuels and cement manufacturing in the world, the main responsible for the , will grow again in 2025. Specifically, 1.1% compared to 2024, as predicted by the report, the analysis in which 130 international experts participate and which this year celebrates its twentieth edition. The main headline, for yet another year, is that emissions will increase to 38.1 gigatons. Since the Paris Agreement was signed in 2015, whose fundamental objective is to reduce greenhouse gases expelled so that they practically disappear by mid-century, CO₂ emissions have grown by 9.8%.
The data is undoubtedly bad because it leads to the worsening of this crisis. The window is increasingly closing to ensure that the increase in average temperature remains within the safety margins established in the Paris Agreement itself. The pact established that the average increase on Earth should remain below 2 degrees Celsius compared to pre-industrial levels, and as far as possible below 1.5. About half of the CO₂ expelled by human activity. If we continue at the same pace as 2025, in just four years the so-called carbon budget to keep the average global temperature below 1.5 degrees will be exhausted.
In fact, from the world of science it is considered inevitable that in the next decade this barrier of 1.5 will be overcome in a stable manner. The only option left to comply with Paris would be for this overshoot to be only temporary, which would require drastic reductions in other short-lived greenhouse gases in the air, and the uncertain techniques for capturing and storing carbon dioxide from the atmosphere.
The carbon budget to meet the 2 degrees objective will be exhausted in 25 years if the current pace continues, the report also points out. Pep Canadell, one of the coordinators of the report and executive director of the Carbol Global Project, speaks of a kind of cat and mouse game, in which the world population and its demand for energy grow year by year and renewables, despite increasing exponentially, do not fully cover all that energy need and displace fossil fuels.
But there is also some hope. “The peak of emissions is very close,” says Canadell. “We are just a few years away,” and it will be during this decade, although Canadell does not dare to specify it in one year. The ceiling of global emissions will be reached by the “exponential growth of renewables.” But reaching the peak, this expert warns, will not be “enough,” because what has to happen right after is that they fall quickly to zero.
According to UN calculations, the new plans that countries are presenting under the Paris Agreement will lead to emissions of all greenhouse gases – not just CO₂ – being reduced by 12% in 2035. Although this is good data, it is not enough to stay within the safety margin: according to the UN, these emissions are required to be 55% lower within 10 years to comply with the 1.5 path and 35% for the of the 2 degrees.
These reductions are, for now, only estimates of what can be achieved with the implementation of the Paris Agreement and the promises of the countries that are part of the treaty. But what has happened so far is that, since it was signed, the world’s carbon dioxide emissions have grown by the aforementioned 9.8%.
Yes, there is a slowdown in the growth rate. In the decade just before, between 2005 and 2015, the increase was 18.8%, almost double that of the following one.
In both cases, both in the growth rates and in the near peak of emissions and the fall forecasts for 2035, China is the key. It is the main world emitter of CO₂—accumulating 32% globally—but it is also the first country in terms of the installation of renewables and the development of electric cars within and outside its borders.
For 2025, the report predicts that China’s CO₂ will grow by 0.4%, but with a high range of uncertainty (between -0.9% and 2%), as Canadell acknowledges. To know the final data we will have to wait until next year. In any case, for the second consecutive year there is a clear slowdown in emissions. This is due, the authors explain, “to moderate growth in energy consumption combined with extraordinary growth in renewable energy generation,” which has led to stagnation in coal use.
For India, which accounts for 8% of global emissions, an increase of 1.4% is forecast, significantly lower than the pace it has had until now. In addition to the growth of renewables, weather conditions have meant that less energy was required this year.
This is just the opposite of what has happened in the EU (6% of global emissions), where cold and windless conditions in many parts of Europe have led to an increase in the use of natural gas and a 0.4% increase in carbon dioxide. This possible increase breaks a sustained trend in emissions in the EU. Canadell, however, is not concerned as he considers it something temporary linked to the weather.
He is more concerned with the situation in the United States, the second largest emitter in the world with a share of 13%. The report shows a 1.9% increase in emissions for this year. And this growth, which breaks the trend of recent years, is linked to the rise in natural gas prices (because the US has exported much more due to the invasion of Ukraine). This has led to more coal being used, which was experiencing a continued decline due to its higher costs than natural gas. This is the most dangerous of the fossil fuels when it comes to global warming.
Regarding the future in the United States, Canadell considers that Donald Trump’s policies against renewables and in favor of fossil fuels, major sponsors of the Republican, are going to have an impact on that country’s emissions. They will fall, this expert predicts, but they will do so more slowly than expected with the previous Administration.
35 countries lead the way
Canadell highlights two more positive points of this year’s edition. On the one hand, the existence of a group of countries – 35 nations that currently accumulate 27% of all carbon dioxide emissions on the planet – that have significantly reduced their gases at the same time as their economies grew in the period between 2015 and 2024. This shows the path that can be followed. Among those countries are most EU members, including Germany, France, Spain, the United Kingdom, the United States, Australia and South Korea. In the previous decade, 2005-2014, they were half that number, 18.
The other point that this expert highlights is the decrease in CO₂ emissions linked to deforestation and changes in land use, which will fall again in 2015. According to the preliminary calculations contained in the report, once the gases expelled by the fossil sector and those linked to land use are combined, this year’s emissions are expected to amount to 42.1 gigatons, slightly less than the 42.4 of 2024.
