According to The Guardian, climate scientists have warned that excessive heat in the Earth’s seas has crossed the “threshold of no return” since 2014.

According to Kyle Van Houtan, a researcher at the Monterey Bay Aquarium and co-author of a new study about the findings published in the journal PLOS Climate, “we’ve shown that climate change is not something that is uncertain and may happen in the distant future — it’s something that is a historical fact and has already occurred.”

“2014 was the first year for the worldwide ocean to reach the 50% threshold of high heat, therefore becoming ‘normal,’ with the South Atlantic (1998) and Indian (2007) basins crossing this barrier earlier,” the researchers wrote in the report.

The findings present a bleak picture that should serve as a forewarning of what’s to come.

Professor John Abraham of the University of St Thomas told the newspaper, “Oceans are crucial to understanding climate change.” “They cover nearly 70% of the planet’s surface and absorb more than 90% of global warming heat,” says the report.