The world has hit Earth Overshoot Day, when people have used up the resources the planet can provide for the year, on the earliest date ever, experts warn.
Earth Overshoot Day marks when people have used up the food, timber and other natural products the Earth can sustainably provide, and the planet has absorbed as many carbon emissions as a result of human activity as it can, for the year.
This year the day has fallen on July 29, the earliest date since humans began overusing the planet's natural resources in the 1970s, the Global Footprint Network, which calculates the date, said.
It means humans are using nature 1.75 times faster than the planet's systems can regenerate - the equivalent of using 1.75 Earths.
Mathis Wackernagel, co-inventor of Ecological Footprint accounting and founder of the Global Footprint Network, said: "We have only got one Earth - this is the ultimately defining context for human existence.
"We can't use 1.75 without destructive consequences."
He warns that humans will have to operate within the means of the Earth's natural resources, either deliberately or as the result of disaster.
The "overspend" of the natural budget is leading to deforestation, soil erosion, the loss of wildlife and build-up of carbon dioxide in the atmosphere which is fuelling climate change.
A campaign to £MoveTheDate is calling on efforts to push the date of Earth Overshoot Day back five days every year to reach a situation where humanity is living within the planet's means before 2050.
Friends of the Earth climate campaigner Aaron Kiely said: "Earth's resources are finite, and we are in a climate emergency.
"Today is a warning about how wrong we are currently getting things because this isn't an overdraft we can dip into and pay back.
"We know what the solutions are so it's time to be hopeful and bold and grab the opportunity to make a positive difference while we still can."
In the UK, Friends of the Earth is calling for the Government to adopt a climate action plan by 2020, including aiming for 100% clean energy, investing in green, affordable transport, banning fracking, funding huge scale insulation and eco-heating schemes and doubling tree cover.
