Just under eight months into the year, humanity has already consumed its annual allotment of renewable resources, a thinktank that tracks mankind's impact on Earth said Thursday.

"If you think of the whole year as a total budget, it turns out we have used it up by August 13," Mathis Wackernagel, president of Global Footprint Network, told AFP.

Referred to as Earth Overshoot Day, it is the estimated date when humanity's demand on nature for the year exceeds what Earth can regenerate annually.

Global Footprint Network estimated that humans would need the resources produced by just over one-and-half Earths to keep up with what we will use this year.

"We spend 1.62 times what Earth can renew," said Wackernagel. "Like with money, you can dip into your inheritance or your savings for a time, but only a certain amount of time."

Humanity is overusing resources, for example, by pumping more carbon dioxide into the air than the planet can adsorb, over fishing or hacking down more trees than nature can regenerate each year.

The group calculated the "overshoot" point by crunching UN data on tens of thousands of sectors like food production and trade. Over the last several decades, the date has been getting progressively earlier in the year.

In 1993 Earth Overshoot Day was on October 21, in 2003 on September 22, and last year on August 19.

According to the group's calculations, humans used only about three-quarters of the Earth's annual resource allotment in 1961. By the 1970s, economic and population growth sent Earth into overshoot.

Some countries already feeling the pinch are places like Haiti, Syria and Afghanistan, all troubled countries which cannot produce everything they need, and cannot afford to buy it either.

"If you don't have the resources to support yourself it gets extremely tight," Wackernagel said.

- Population surge -

Global Footprint Network sees the climate talks in Paris later this year -- where the UN is aiming to get a global agreement to reduce greenhouse gasses -- as a chance to change.

Assuming global carbon emissions are reduced by at least 30 percent below today's levels by 2030, Earth Overshoot Day could improve to September 16, 2030, the group said.

Meanwhile, new data released at a conference in the United States on Monday indicated that the demand for resources is unlikely to slow as the world's population is expected to boom in the coming decades.

The number of people on Earth is forecast to grow from 7.3 billion now to 11.2 billion by the end of the century, John Wilmoth, director of the UN's population division, said at the Seattle conference of global statisticians.

High fertility rates in Africa are one of the key drivers of the increase, with the continent's number of people expected to swell from 1.2 billion at present to as many as 5.6 billion by 2100.

Wilmoth said the growing population could make worse a range of problems like pollution, distributing scarce resources as well as political instability and crime.