Humans have already used up their allowance for water, soil, clean air and other resources on Earth for the whole of 2017.
Earth Overshoot Day is on 2 August this year, according to environmental groups WWF and the Global Footprint Network.
The date, earlier this year than in 2016, means humanity will survive on “credit” until 31 December.
“By August 2 2017, we will have used more from Nature than our planet can renew in the whole year,” the groups said in a statement.
“This means that in seven months, we emitted more carbon than the oceans and forests can absorb in a year, we caught more fish, felled more trees, harvested more, and consumed more water than the Earth was able to produce in the same period.”
According to campaigners, the equivalent of 1.7 planets would be needed to produce enough natural resources to match our consumption rates and a growing population.
The Earth Overshoot Day measure has been calculated since 1986 and the day has never fallen so early as in 2017. It looks at the balance between global footprint – what humans take from the earth – and biocapacity, which allows us to produce resources and absorb our waste.
In the 1980s, the overshoot day fell in November, shifting back to October by 1993 and to September just after the millennium.
By 2016 it had reached 8 August.