Australia has dropped a few spots on a list of the worst-polluting countries in the world.

Australia's environmental situation has improved in the last year, according to the WWF's biennial Living Planet Report.

In a small bit of good news – WWF says water quality on the Great Barrier Reef has improved with a 15 per cent reduction in pesticide pollution and 13 per cent reduction in fertiliser pollution.

But the international conservation group has warned that the planet is still struggling to sustain the demands of modern life.

The Living Planet Report lists the ecological footprints of 152 nations, and has placed Australia at 13th on the ranking of largest ecological footprint per person.

Despite its low population, Australia ranks highly due to significant industrial carbon emissions and the impacts of crops and grazing.

Statistically, if the rest of the world lived like Australians it would need 3.6 Earths to sustain the demands on nature.

But the country is getting better, it seems, as Australia's ecological footprint was ranked seventh largest in 2012.

High-income countries have a per-capita ecological footprint around five times larger than low-income countries, but the poorer regions tended to suffer the greatest ecosystem losses.

Alarmingly, the report also found wildlife populations worldwide have more than halved in just 40 years.

The figure was according to the Living Planet Index, which is run by the Zoological Society of London and tracks over 10,000 vertebrate species populations from 1970 onwards.

“The scale of biodiversity loss and damage to the ecosystems essential for our well-being is alarming and a direct consequence of the way we produce and consume,” WWF Australia chief executive Dermot O'Gorman said.