Earth Approaches a Second Year Exceeding the 1.5°C Climate Goal

The aim of restricting global warming to below 1.5°C faces challenges as recent climate data suggests global temperatures remain alarmingly high, with 2025 tracking closely to 2024’s record heat.

April 2025 marked the second hottest April on record, losing out only to April 2024, as per reports from the European Union’s Copernicus climate service and the nonprofit Berkeley Earth. That month, global temperatures consistently exceeded 1.51°C above pre-industrial levels, marking 22 consecutive months over this critical threshold. Copernicus reports. The average temperature for April 2025 remained cooler than April 2024, still surpassing pre-industrial levels by 1.49°C.

This unrelenting warmth has astounded scientists. The year 2024 was deemed the hottest on record, with an average global temperature exceeding 1.55°C above the pre-industrial average. It marked a significant event as it was the first calendar year to surpass the 1.5°C threshold. Under the 2015 Paris Climate Agreement, nations pledged to limit global temperature increases to well below 2°C, ideally to 1.5°C.

Scientists had anticipated that the cooling effects of the La Niña weather pattern would emerge in January, offering some relief. However, global temperatures have remained persistently elevated, raising concerns about 2025 possibly following 2024 in exceeding the critical 1.5°C marker. “The recent La Niña event hasn’t provided the expected cooling relief,” stated Robert Rohde from Berkeley Earth during a briefing on May 13.

Data from Berkeley Earth suggests an 18% likelihood that 2025 will be the hottest year recorded, and a 53% chance of it being the second hottest. Rohde estimates a 52% probability of having an average temperature exceeding 1.5°C this year.

The trajectory of global temperatures for the remainder of the year relies heavily on whether new El Niño or La Niña patterns emerge in the Pacific, according to Rohde.

The ongoing hot streak has dashed hopes of capping global temperatures at the 1.5°C Paris target. Although targets are assessed over a 20-year average, researchers are increasingly worried that recent high-temperature streaks have led to a breach of this threshold. “It’s becoming inevitable that we’ll see a long-term average above 1.5°C in the next decade,” Rohde cautioned.

Last year, scientists warned that exceeding 1.5°C would result in a three-year period of significant temperature rise, effectively compromising the goals of the Paris Agreement. Similarly, a paper released earlier this year indicated that 12 consecutive months above 1.5°C have already signaled a long-term warming trend at that level.

Richard Allan from the University of Reading expressed surprise at the durability of the warmth. Findings from the past two years and new record temperatures have fundamentally altered the scientific perspective on the feasibility of limiting warming to 1.5°C. “Without substantial mitigation efforts or extraordinary volcanic events in the next 20 years, we expect we will be above the 1.5°C threshold,” he remarked.

Nevertheless, he maintains that the Paris Agreement’s goal of limiting warming to below 2°C remains attainable. “It is crucial to strive for temperatures beneath that threshold,” he emphasized.