The Earth may have already entered an era of intensified global heating that the Paris Agreement was aimed to avert, two new studies examining the record breaking temperatures of 2024 have found.
The research, published in Nature Climate Change, suggests the unprecedented heat last year could mark the beginning of a multi-decade period where the average global temperature consistently exceeds 1.5C above pre-industrial levels.
In 2024, temperatures rose above 1.5C for 12 consecutive months.
This matters because 1.5C is the key target set by the 2015 Paris Agreement, the level countries were trying to avoid exceeding to limit catastrophic climate impacts.
The first study, from Germany, suggests Earth has likely entered a 20-year period where global temperatures will consistently average above 1.5C.
“Multiple datasets and approaches from different organisations converged on a 2024 average increase of 1.55C above the pre-industrial baseline," the study says.
The second study, led by researchers from Canada, says June 2024 marked the 12th consecutive month with global mean surface temperatures at least 1.5C above pre-industrial levels.
The study shows that having 12 consecutive months above 1.5C means there’s a 76 per cent chance that we’ve already hit that long-term warming threshold under current climate policies.
If this trend continues for 18 consecutive months, the research says, the breach of the Paris Agreement threshold will be virtually certain. January 2025 was the 19th month to cross that mark.
Dr Andrew King, senior lecturer in climate science at the University of Melbourne, who was not part of either study, says the research highlights how "single months and years over the 1.5C mark are likely to be features of a longer period the world has entered in which the climate averages more than 1.5C of global warming”.
Without rapid decarbonisation, he warns, it will be difficult to prevent the climate from remaining above this threshold.
"Global greenhouse gas emissions remain at or near record levels, and global warming has even accelerated in recent years.
“A major shift is needed to decarbonise our society and economy; otherwise, we will keep warming the planet and causing more and more damage.”
These studies are a timely reminder of how far we really are from tackling climate change properly.
But Dr Tom Mortlock, head of climate analytics Asia-Pacific at Aon and Adjunct Fellow at the Climate Change Research Centre at UNSW, adds: "2024 was the warmest year on record globally, with average temperatures exceeding 1.5C. While often used interchangeably, this is not the same thing as breaching the Paris Agreement threshold of 1.5C."
He explains that the Paris Agreement's targets refer to 20-year averages, meaning we won’t officially know if we’ve crossed the threshold until years after it happens.
"Whether we have [breached the Paris target] or not, the fact remains that we only have about six years left in the global carbon budget at current rates to give ourselves a 50/50 chance of still making the Paris target.
"If this new research is correct, 2024 may be the first sign that we have already overshot this target."
These warnings come after confirmation from the World Meteorological Organisation (WMO) that 2024 was the hottest year on record, with global temperatures approximately 1.55C above pre-industrial levels.
The impacts of this warming are already being felt globally. From deadly wildfires in California to catastrophic flooding in Valencia, Nepal, and Sudan, studies have shown climate crisis has made extreme weather worse.
Scientists say the time has come when we have to make hard choices in order to prioritise the climate.
“Get ready for a '1.5 world'” says Dr Paul Read, director of the Future Emergency Resilience Network (FERN).
“Sometime soon we're going to have to make serious alterations to our socioeconomic, energy, and infrastructure systems that transcend 'politics as usual’.
“We can do it with resource wars and misery or else creativity and compassion. I like to think most people would choose the latter no matter what flavour of politics they prefer."
