There's a 50:50 chance the planet will pass the 1.5C warming threshold in the next 5 years

(CNN)There's now a 50:50 chance that the world will surpass a critical threshold of 1.5 degrees Celsius of global warming in the next five years, a new World Meteorological Organization report shows, warning of heating that could have devastating impacts on systems like coral reefs as well as Arctic ice.

The report says that surpassing the limit is likely to be temporary -- temperatures could come back down again -- but science shows that even a temporary overshoot could bring irreversible changes to the planet.

The report warns that at least one year between 2022 and 2026 will surpass the 1.5C mark and that there is a 93% chance that the period will see the warmest year on record. It's also almost certain that, on average, the next five years will be hotter than the last five.

In 2015, the chances of world temperatures temporarily exceeding 1.5C over the next five years were close to zero. Those odds have been inching up ever since as humans continue to emit greenhouse gas, primarily from the use of fossil fuels.

Scientists have warned that the world needs to limit global warming to 1.5C above the temperatures experienced before industrialization to avoid the more catastrophic effects of the climate crisis. In 2015, most of the world signed onto the Paris Agreement, aiming to limit temperature rise to 2C, but preferably 1.5C.

The world is already at least 1.1 degrees Celsius warmer than it was before industrialization.

"This study shows -- with a high level of scientific skill -- that we are getting measurably closer to temporarily reaching the lower target of the Paris Agreement on Climate Change," WMO Secretary General Petteri Taalas said in a statement accompanying the Global Annual to Decadal Climate Update.


The report says that surpassing the limit is likely to be temporary -- temperatures could come back down again -- but science shows that even a temporary overshoot could bring irreversible changes to the planet.