Scientists have warned that the planet is heading towards a climate disaster.
More than half of the turning points, which could lead to irreversible changes on Earth and threaten civilization, have become active, the scientists said in an article in the journal Nature.
They pointed out that nine turning points could have a sequential effect such as dominoes.
"We fear that it will be impossible to stop this relay, forming a chain that would threaten the existence of human civilizations," the article said.
Active turning points include the loss of Arctic sea ice, the Greenland and Antarctic ice sheets, the permanent melting of ice and the destruction of northern forests and the Amazon rainforest.
The scientists called for urgent action to take strong action to reduce emissions beyond the 2015 Paris Agreement.