International efforts to tackle climate change reached a major milestone with the Paris Agreement, adopted by more than 190 countries. The agreement aims to limit the average global temperature rise to well below 2 °C, preferably to 1.5 °C. However, questions remain as to whether current national climate pledges are sufficient to meet these goals.
Against this backdrop, a new collaborative study by Assistant Professor Taeyoung Jin of Jeonbuk National University and researchers from Pusan National University evaluated the impact of current climate pledges. Their analysis shows that even if countries follow existing plans, global temperatures could reach 2.48 °C by 2300. This paper was made available online on November 17, 2025 and was published in Volume 174 of the journal Environmental Science & Policy on December 1, 2025.
"Even if every country keeps its current promises to cut carbon emissions, the world is still on track to warm by about 2.5 °C, which is higher than the internationally agreed 2 °C safety limit," says Dr. Jin.
The team carried out their analysis using the Regional Integrated Model of Climate and the Economy (RICE-2010). This model simulates how economic activity, emissions, and climate change interact across different global regions. It works through a feedback process in which economic growth leads to carbon emissions, emissions drive climate change, and climate impacts cause economic damage that can hinder future growth.
The researchers incorporated real-world policy commitments into the model, including nations' 2030 emission reduction targets and long-term net-zero goals. They then projected outcomes up to the year 2300 under four scenarios: (1) a business-as-usual (BAU) scenario with no emission cuts; (2) a social optimum scenario focused on maximizing welfare; (3) a net-zero scenario based on actual country commitments; and (4) a 1.5 °C-compliant pathway.
Under the BAU scenario, global temperatures could rise by as much as 7 °C by 2300. In contrast, the net-zero scenario—based on current pledges—limits warming to approximately 2.48 °C. While this represents significant progress compared to a no-action baseline, it still falls short of the 2 °C target.
The study also estimates that an additional reduction of approximately 5 gigatonnes of CO2-equivalent emissions by 2030 is required to meet the 2 °C goal. Without more rigorous mitigation, total global climate-related damages could reach nearly US$65 trillion by 2200. However, these risks could be mitigated to about US$19 trillion under the net-zero scenario, and further to roughly US$15 trillion under a pathway aligned with the 1.5 °C goal.
Without stronger action, the world could face more extreme heatwaves and floods, higher food and energy prices, and greater economic instability, say the researchers. However, if countries act earlier and cooperate more closely, long-term climate risks can be dramatically reduced.
"Our data reveal that today's climate promises are important—but they are not enough. However, if countries act earlier and more decisively, the overall damage from climate change can be significantly reduced, even if it requires short-term economic adjustments," reflects Dr. Jin.
These findings provide crucial evidence for policymakers as they prepare to update their national climate pledges, highlighting that it is high time for more ambitious and immediate action.
