Geneva, Sep 30 (IANS): The World Wide Fund for Nature (WWF) said Tuesday that the global wildlife population has declined by more than half over the last four decades.

The Living Planet Report 2014, the 10th edition of WWF's biennial publication, said the population of fish, birds, mammals, amphibians and reptiles have declined by 52 percent since 1970, Xinhua reported. Freshwater species have suffered a 76 percent decline, an average loss almost double that of land and marine species.

The report noted that the biggest recorded threat to biodiversity comes from the combined impacts of habitat loss and degradation. Fishing and hunting are also significant threats.

In addition, the report noted climate change was becoming increasingly worrisome, with research finding that climate change was already responsible for the possible extinction of species.

It also said the ecological footprint, a measure of humanity's demands on nature, continued its upward climb and humanity's demand on the planet was more than 50 percent larger than what nature could renew.

"The findings of this year's Living Planet Report make it clearer than ever that there is no room for complacency," WWF's Director General Marco Lambertini said in a statement.

"Biodiversity is a crucial part of the systems that sustain life on earth, and the barometer of what we are doing to this planet, our only home," he added.

He called for bold global action in all sectors of society to build a more sustainable future.

WWF is one of the world's largest and most respected independent conservation organisations. WWF's mission is to stop the degradation of the earth's natural environment and to build a future in which humans live in harmony with nature.