TOKYO - It is imminent and unavoidable that the rise in global temperatures above preindustrial levels will exceed 1.5 C due to decades of insufficient climate action, a U.N. Environment Program report said Wednesday, calling for urgent emissions cuts to minimize the magnitude and duration of overshoot.
To achieve the "lowest possible" temperature overshoot scenario with a peak rise of 1.7-1.8 C before returning to or below 1.5 C by 2100, UNEP said that global greenhouse gas emissions would have to be reduced by 18 percent from the 2025 level by 2030, 45 percent by 2035 and 69 percent by 2040.
While countries are set to implement their Nationally Determined Contributions -- standards set by the Paris Agreement in 2015 -- doing so would only cut emissions by 5-8 percent by 2030 and 11-15 percent by 2035 relative to 2025, according to the report.
UNEP Executive Director Inger Andersen warned that every additional fraction of a degree and additional year of warming above the 1.5 C threshold increases impacts and risks, such as fatal floods, heatwaves and wildfires.
"So, we must pull out all the stops to minimize peak warming and return to 1.5 C by the end of the century. This is possible," Andersen said.
Global emissions in 2025 totaled 58.4 billion tons of CO2 equivalent, almost flat from 2024, according to the report. To achieve the 1.5 C target under the scenario, the world needs to remove 320 billion tons of carbon dioxide over the course of the century.
China was the largest emitter of greenhouse gases in 2025 at 16.1 billion tons, followed by the United States at 6 billion tons, India at 4.5 billion tons, and the European Union at 3.1 billion tons.
Japan's emissions reached around 1.05 billion tons in fiscal 2024 through March 2025, according to the Environment Ministry.
Meanwhile, the report said there are more opportunities to accelerate climate action, with global renewable electricity capacity growing three times faster than expected and solar photovoltaic build-out rising seven times faster since the adoption of the Paris Agreement.
In contrast, total energy supply from coal and oil has grown slower than projected, with climate policies cutting emissions in many places, it said.
