The world may have already missed its chance to limit global warming to 1.5 degrees Celsius, according to two new studies in Nature Climate Change.

The Paris Agreement was inked in 2015, with 196 countries agreeing to rein in greenhouse gas emissions to keep the global average temperature increase to "well below” 2 C and ideally cap it at 1.5 C compared to preindustrial times. The new analyses show the world will surpass the latter, underscoring the urgent need to cut carbon emissions.

"Every increment of warming above 1.5 degrees Celsius means worse extremes,” said Alex Cannon, a research scientist with Environment and Climate Change Canada, and author of one of the studies. "If we continue warming the atmosphere, consequences will be greater.”

In 2024, global temperatures reached 1.5 C for the entire year, the first time it’s happened in recorded history. It was a stark departure from previous projections: The Intergovernmental Panel on Climate Change report published just a year earlier suggested that temperatures would reach 1.5 C in the early 2030s if emissions weren’t cut. The breach left scientists wondering, "is this a sign? Are these short-term exceedances above that level indicative of us actually reaching that target sooner than we expected?” said Cannon.

The reason for those questions is because the Paris Agreement’s 1.5 C threshold isn’t focused on daily or even yearly temperatures. Instead, it’s based on a 20-year retrospective average, which means the world won’t know it’s hit 1.5 C until after the fact. The two new studies attempt to get around that by using climate models to look ahead based on current data to see if we’ve already entered a 20-year period above 1.5 C.

Cannon’s study, and a separate study led by Emanuele Bevacqua, a climate scientist at the Helmholtz Centre for Environmental Research in Germany, both suggest that’s exactly what’s happened.

"I pronounce the 1.5 C target mostly dead," Kate Marvel, a research physicist with NASA Goddard Institute for Space Studies who was not part of either study, said in an email. "Yes, a single year over 1.5 C doesn’t necessarily mean the average temperature over the next 20-year period is going to be 1.5 C,” she said, "but these papers make a pretty compelling case that in models, the first single year above 1.5 C is likely to fall within that 20-year period.”

The findings are part of a growing body of research warning the world that its climate targets are increasingly out of reach and that heating is accelerating. In fact, this January was the hottest on record despite the cooling influence of an emerging La Nina.

The new studies put the odds of being in the midst of a 20-year period where the Earth breaches 1.5 C to be somewhere between "likely” and "virtually certain.” Despite that, both Cannon and Bevacqua agree that heating can be arrested by drastically reducing fossil fuel use.

But the chance of that happening is shrinking given the Trump administration’s assault on climate action. Since taking office, his administration has taken steps to increase fossil fuel production and withdraw the U.S. from the Paris Agreement. Other world leaders are reportedly considering following suit, creating headwinds for the deep emissions cuts needed.

The 1.5 C threshold was included in the Paris Agreement largely at the behest of small island developing states, many of which would be wiped off the map by sea level rise should the planet heat beyond it. More recent research has found that even at 1.5 C, small island developing states risk flooding from sea level rise.

"Even if we reach the 1.5-degree global warming level threshold in the future, we should still aim to not exceed this too much or even make sure that this is our temporary exceedance so that we can stabilize the temperature and at some point cool the temperature,” said Bevacqua.

That’s been a rallying cry for years. The world, though, has failed to heed it as carbon pollution has continued to climb to record highs.

"Rapid near-term emissions cuts can limit peak warming and reduce climate risks,” said Marvel. "Whether or not that merits action is not (just) for scientists to decide.”