The Paris Agreement, adopted in 2015, represents an international commitment aimed at limiting the increase in global average temperature by 2100. well below 2 °C compared to pre-industrial levels, with the aim of keeping it below 1.5°C. This goal is achieved through individual countries' Nationally Determined Contributions (NDCs).

A new probabilistic assessment of climate change prospects in the post-Paris Agreement period (2015–2024), based on a Bayesian statistical approach, yields mixed results. Analysis, which is based on an equation expressing emissions as the product of population, GDP per capita and carbon intensity, confirms that efforts to mitigate carbon dioxide emissions have been more than offset by rapid economic growth.

Significant progress in intensity, despite rising emissions

Data from the first nine years of the Paris Agreement (2016-2024) showed a substantial improvement in one of the key components: carbon intensity (CO2 emissions per unit of GDP). Global carbon intensity decreased by 25 % between 2015 and 2024, representing an annual rate of improvement 3,1 %This pace is significantly faster than the historical average from 1960-2015, which was just 1.1 % per year.

Despite this significant progress, total CO2 emissions worldwide not only did they not fall, but they increased significantly by 5.6 % (average annual increase of 0.6 %) in the post-Paris period.

The main reason why emissions have continued to rise lies in economic growth metrics: world Gross Domestic Product (GDP). World GDP (measured on a purchasing power parity basis, PPP) grew by 41 %, which represents an annual increase 3,9 %This rapid economic growth more than canceled annual improvement in carbon intensity (3.1 % per year). This dynamic illustrates why climate change is called a “super hard problem”, as the rapid economic growth that is the aspiration of many governments has led to a dramatic setback in emissions reductions.

Differences in world economies

Different world economies have shown different results:

• China achieved an outstanding reduction in carbon intensity (37 % reduction), meeting and slightly exceeding its NDC-1 target. However, its exceptionally rapid economic growth has led to a massive increase in total CO2 emissions of 18 %.
• USA They saw a 10 % decrease in CO2 emissions (close to their NDC-1 target of a 15 % reduction) and a 32 % decrease in carbon intensity.
• Germany reduced CO2 emissions by 28 % and carbon intensity by 37 %.

Interestingly, although China, the US and Germany have achieved similar percentage improvements in carbon intensity (in the range of 32–37 %), their absolute intensity levels differ dramatically: the US intensity is about 50 % higher than Germany, while China’s intensity is more than three times compared to Germany. This suggests that countries with higher emissions have significant room for rapid and massive improvement.

Implications for global warming

As a result of the fact that total emissions have increased despite improvements in intensity, the expected increase in global average temperature by 2100 has been reduced only modestly. While data up to 2015 predicted a warming of 2.6°C, new data up to 2024 have only pushed this projection down to 2.4°C.

The likelihood of keeping warming below 2°C remained low – at 17 %However, the risk of the most catastrophic warming (above 3°C) has been substantially reduced, from 26 % to 9 %.

To achieve the 2°C target, all countries would need to meet their more ambitious NDC-2 commitments and continue at this pace beyond 2030 (the so-called “Continued” scenario). In this case, the projected temperature increase would be reduced to 2.0°C and the probability of staying below 2°C would reach 53 %However, if only the original NDC-1 targets were met and efforts continued, the probability of staying below 2°C would be only 34 %. To achieve a 66 % probability of staying below 2°C, the largest emitters require further increases in their NDC targets (e.g. China by 13 % and the US by 14 % above NDC-1). JRi

More information: Jitong Jiang et al., Climate change mitigation efforts to reduce carbon dioxide emissions and meet the Paris Agreement have been offset by economic growth, Communications Earth & Environment (2025).