The latest forecasts from the World Meteorological Organization (WMO) indicate that there is 70% chance that the average global temperature in the period 2025-2029 will be more than 1.5 °C higher as in pre-industrial times (reference period 1850-1900). This 1.5°C limit is particularly important because the world’s governments committed to limiting global warming to this level in the 2015 Paris Climate Agreement. The agreement aims to keep the temperature increase “well below 2°C” and to “pursue efforts to limit it to 1.5°C”, recognizing that this would “significantly reduce the risks and impacts of climate change”.

However, scientists from the WMO and the Intergovernmental Panel on Climate Change (IPCC) emphasize that global temperature increases should be properly measured as 20-year average, not as an average over a short five-year period. For this reason, the predicted exceedance of 1.5°C in 2025-2029 does not automatically mean a breach of the Paris Agreement target, which is assessed based on the longer-term average. To estimate the 20-year average, meteorologists use a combination of observations over the past ten years and forecasts for the next ten years. According to this methodology, the 20-year average of global temperatures in 2024 was 1.44°C higher than in the pre-industrial period, although the year 2024 itself was 1.55°C warmer. Physicist Adam Scaife noted that "on a global average we are still below 1.5°C".

Despite the measurement methodology, the predictions for the coming years are worrying. In addition to the 70% chance of exceeding 1.5°C on average in the period 2025-2029, the WMO report states 80% probability that at least one year between 2025 and 2029 will be warmer than the warmest year so far, 2024It is even 86% chance that at least one year in this period will be more than 1.5°C warmer than pre-industrial levels. The predictions also include 1% chance that one year in 2025-2029 will be more than 2°C above pre-industrial levelsScaife called the possibility "shocking" as it was "virtually impossible" just a few years ago.

Keeping warming below 1.5°C, even in the long term, would require a “lucky intervention from natural climate variability,” such as the La Niña phenomenon, according to Adam Scaife, but it is "highly unlikely"Leon Hermanson of the UK Met Office added that a volcanic eruption would "change the forecast considerably" because it would temporarily lower temperatures.

WMO Director of Climate Services Chris Hewitt stressed that while it is tempting to focus on whether the 1.5°C limit has been exceeded, "Every tenth of a degree counts - it's really important to keep warming as low as possible"The Paris Agreement, he said, has already contributed to reducing the expected increase in temperatures. The upcoming COP30 climate talks in Brazil are seen as an important "an opportunity for the world to unite" and for politicians "take climate action". Spring