Populations of mammals, fish declined by 60 percent.

Earth's biodiversity has experienced a period of cataclysmic destruction and loss in recent decades with wild vertebrate populations declining by nearly two thirds, according to a report published by the WWF on Tuesday.

Populations of mammals, birds, fish, reptiles and amphibians declined by 60 per cent between 1970 and 2014, the most recent year of available data, the conservation group said in its Living Planet Report.

Human activities, including habitat destruction and degradation, as well as over-fishing and over-hunting and other forms of overexploitation were among the primary causes of the decline.

"We may be the last [generation] that can take action to reverse this trend," the report warned. "From now until 2020 will be a decisive moment in history."

The level of decline was extremely high in South and Central America, where 89 per cent of vertebrates were lost.

Freshwater species were also severely affected, experiencing an 83 per cent decline.

"There cannot be a healthy, happy and prosperous future for people on a planet with a destabilized climate, depleted oceans and rivers, degraded land and empty forests, all stripped of biodiversity, the web of life that sustains us all," WWF director general Marco Lambertini wrote in the report.

A review of progress on sustainable development in 2020 - following goals set by the UN in 2015 and the 2015 Paris climate agreement - is when the world should "embrace a new global deal for nature and people, as we did for climate in Paris," he said.