"Unfortunately, time is up."
That's the bleak warning headlining a concerning new report where climate scientists conclude Earth's vital signs are now worse than anything humans have seen.
The climate situation is now so bad that life on Earth is imperilled, the scientists said, pointing to 20 of 35 identified planetary vital signs that are teetering at record extremes.
Those red-lining vital signs meant "profoundly distressing scenes of suffering" will unfold on the planet's population, the report published today in Bioscience declared.
One of the paper's lead scientists predicted "we're on our way" to a world hallmarked by "unbearable heat and shortages of food and freshwater".
"Life on planet Earth is under siege," the report said, while presenting a range of climate and disaster data scientists said showed that "we are now in an uncharted territory".
The report said for decades scientists had been warning of a future "marked by extreme climatic conditions" because of escalating global temperatures caused by human activities that release greenhouse gasses into the atmosphere.
"We are seeing the manifestation of those predictions as an alarming and unprecedented succession of climate records are broken, causing profoundly distressing scenes of suffering to unfold.
"We are entering an unfamiliar domain regarding our climate crisis, a situation no one has ever witnessed firsthand in the history of humanity."
Data in the report illustrated how many climate records were broken by "enormous margins" in 2023, particularly ocean temperature and sea ice records, scientists said.
In July, Earth recorded its highest average surface temperature ever; scientists said there was reason to believe it was the highest temperature in the last 100,000 years.
This year there have already been 38 days with global average temperatures more than 1.5 degrees Celsius above pre-industrial levels, the report said, and an "extraordinary series" of climate-related records had been broken around the world.
The rapid pace of change had surprised scientists and caused concern about the approach of damaging tipping points "sooner than expected", the report continued.
"Exceptional heat waves" had swept the world, leading to record high temperatures, and the oceans "have been historically warm" in 2023.
This year had seen "unprecedented low levels" of sea ice surrounding Antarctica.
All of those climate indicators were a sign that "we are pushing our planetary systems into dangerous instability", the report said.
Professor William Ripple, a lead co-author of the report, was deeply concerned by his team's findings, and feared for a kind of societal "collapse" and what may be coming.
"Without actions that address the root problem of humanity taking more from the Earth than it can safely give, we're on our way to the potential partial collapse of natural and socioeconomic systems and a world with unbearable heat and shortages of food and freshwater."
Ripple said the report found "little progress" as far as humanity combating climate change.
"The statistical trends show deeply alarming patterns of climate-related variables and disasters," he said.
Dr Thomas Newsome, from the Global Ecology Lab at the University of Sydney, one of the co-authors of the study, said humans needed to "drastically speed and scale up efforts" to combat climate change.
"Extreme weather and other climate impacts are disproportionately felt by the poorest people, who have contributed the least to climate change," he said.
Global daily mean temperatures never exceeded 1.5 degrees above preindustrial levels prior to 2000, and have only occasionally exceeded that number since then.
However, the report said that 2023 had already seen 38 days with global average temperatures above that mark by 12 September - more than any other year.
In 2023, climate change likely contributed to a number of major extreme weather events and disasters, the report said.
The devastating wildfires which ripped across Canada this northern hemisphere summer had pumped more than 1 gigaton of carbon dioxide into the atmosphere.
That enormous discharge was greater than Canada's total 2021 greenhouse emissions.