According to new data from Copernicus, the European Union's climate monitoring service, the planet has just reached a "shocking" new milestone, enduring 12 consecutive months of unprecedented heat.
Copernicus data shows that every month from June 2023 to May 2024 was the world's warmest month on record.
The 12-month heatwave was "shocking but not surprising" given man-made climate change, said Copernicus director Carlo Buontempo, who warned of worse to come. Unless pollution from planet-warming fossil fuels is curbed, "this streak of warmest months will go down in history as relatively cold," he said.
Copernicus published its data on the same day that António Guterres, Secretary General of the United Nations, gave an impassioned speech in New York on climate change, labeling fossil fuel companies as the "godfathers of climate chaos" and for the first time explicitly calling on all countries to ban advertising of their fossil fuel products.
Guterres urged world leaders to quickly take control of the spiraling climate crisis or face dangerous tipping points. "We are playing Russian roulette with our planet," he said on Wednesday. "We need an exit off the highway to climate hell."
As temperatures rise, global climate commitments are "hanging by a thread," he warned.
Copernicus data shows that every month since July 2023 has been at least 1.5 degrees warmer than temperatures before industrialization, when humans began burning large amounts of planet-warming fossil fuels.
The average global temperature over the past twelve months was 1.63 degrees above this pre-industrial level.
Under the 2015 Paris Climate Agreement, countries agreed to limit global warming to 1.5 degrees above pre-industrial levels. Although this target refers to warming over decades, rather than a single month or year, scientists say this break is an alarming signal.
"This is a harbinger of increasingly dangerous climate impacts close to the horizon," said Richard Allan, a climate professor at the University of Reading in Britain.
The news comes as the western US experiences its first heat wave yet this summer, with temperatures reaching triple digits. But unprecedented heat has already left a trail of death and destruction across the planet this spring.
Dozens of deaths have occurred in India in recent weeks as temperatures soared toward 50 degrees Celsius (122 Fahrenheit); brutal temperatures in Southeast Asia have led to deaths, school closures and shriveled crops; and as the heat increased in Mexico, howler monkeys fell dead from the trees.
The hotter air and oceans also bring heavier rainfall and devastating storms like those that have hit the United States, Brazil, Kenya and the United Arab Emirates this year.
The recent heat offers "a window into the future with extreme heat that will challenge the limits of human survival," said Ben Clarke, a researcher at the Grantham Institute at Imperial College London. "It is critical that people understand that every tenth of a degree of warming exposes more people to dangerous and potentially deadly heat," he told CNN.
"Extreme events, fueled by climate chaos, are piling up, destroying lives, devastating economies and harming health," Gutteres said.
Humanity has an outsized impact on the world, he said, likening it to the meteor that started the process of wiping out dinosaurs 66 million years ago.
"In the case of climate, we are not the dinosaurs," Guterres said. "We are the meteor. We are not alone in danger. We are the danger."
An even hotter future
Global temperatures are expected to fall below record levels in the coming months as El Niño - a natural climate phenomenon that is raising the Earth's average temperature - weakens.
But that doesn't mean the end of the long-term trend of rising temperatures as humans continue to burn fossil fuels that warm the planet. "While this streak of record months will eventually be interrupted, the overall signature of climate change remains and there are no signs of a change in such a trend," Buontempo said.
Guterres' speech also referenced new data released by the World Meteorological Organization, which showed a nearly 86% chance that at least one of the years between 2024 and 2028 will break the warmest annual record, set in 2023.
The WMO also calculated a nearly 50% chance that the global average temperature over the entire five-year period between 2024 and 2028 would be more than 1.5 degrees above pre-industrial levels. That would bring the world closer to exceeding the long-term limit of 1.5 degrees that is central to the Paris Agreement.
Guterres placed the blame for the climate crisis squarely on fossil fuel companies that are "raking in record profits and consuming trillions in taxpayer-funded subsidies," he said.
These companies have spent billions of dollars over the past decades "to distort the truth, mislead the public and sow doubt," he added. He called on every country to ban fossil fuel advertising, similar to advertising bans introduced around the world for other products that harm human health, such as tobacco.
"We are in a moment of truth," he said, adding that the battle for a livable planet would be won or lost this decade.
He called on world leaders to take immediate action, including massive cuts in global warming pollution and an immediate end to all new coal projects. He urged rich countries to phase out coal by 2030, cut oil and gas production by 60% by 2035 and increase the flow of finance to the poorest, most climate-sensitive countries.
"We cannot accept a future where the wealthy are sheltered in air-conditioned bubbles while the rest of humanity is ravaged by deadly weather in unlivable countries," Guterres said.
For more CNN news and newsletters, create an account at CNN.com
