2023 was the warmest year on record by a huge margin

The World Meteorological Organization (WMO) confirmed Friday that last year officially broke the world temperature record, with the global annual average rapidly approaching the critical threshold of 1.5°C above pre-industrial levels.
The agency uses six major international datasets to monitor global temperatures, which reveal a new annual average temperature of 1.45°C above the pre-industrial era (1850-1900).
All months between June and December set records. July and August were the two warmest months on record, according to the organisation.
The 1.5°C figure is the temperature limit set in the 2015 Paris Agreement on Climate Change, but it refers to the temperature increase over decades, not to a specific year such as 2023.
The Earth continues to warm
"Climate change is the greatest challenge facing humanity. It is affecting us all, especially the most vulnerable," said the WMO secretary-general, presenting the report's findings. "We cannot afford to wait any longer. We are already taking action, but we have to do more, and we have to do it fast."
To do this, Celeste Saulo explained, we need to drastically reduce greenhouse gas emissions and accelerate the transition to renewable energy sources.
Looking ahead, she warned that since the cooling La Niña phenomenon was replaced by an El Niño warming in the middle of last year - which usually has the greatest impact on global temperatures after peaking - 2024 could be even warmer.
Celeste Saulo, who took office on 1 January, explained that "while El Niño events occur naturally and come and go from year to year, longer-term climate change is intensifying and this is unequivocally due to human activities".
Scorched earth
Since the 1980s, each decade has been warmer than the previous one, and the last nine years have been the warmest on record. Figures extracted from the six datasets show that the decadal average temperature increase in 2014-2023 was around 1.20°C.
"Humanity's actions are scorching the Earth. 2023 was merely a foretaste of the catastrophic future that awaits us if we do not act now. We must respond to the unprecedented rise in temperature with unprecedented action," said UN Secretary-General António Guterres in response to the latest data.
"We can still avoid the worst climate catastrophe. But only if we act now with the ambition needed to limit global temperature rise to 1.5 degrees Celsius and achieve climate justice," he said in a statement.
Long-term monitoring of global temperatures is only one indicator of how the climate is changing.
Other key indicators include atmospheric concentrations of greenhouse gases, ocean heat and acidification, sea level, sea ice extent and glacier mass balance, to name a few. The WMO's interim report on the state of the world's climate in 2023, published on 30 November, shows that records have been broken in all areas.