More than half of the world's wildlife has disappeared over the past 40 years and humans are largely attributed to this loss, a report by the conservation group World Wildlife Fund (WWF) revealed on Tuesday.

The Living Planet Report, which is published biannually by the WWF and is based on the Living Planet Index of the Zoological Society of London that monitors over 10,000 vertebrate species, revealed that the decline in the population of the world's animals is worse than previously believed. Two years ago, the WWF's report put the figure of wildlife loss at only 28 percent for the period between 1970 and 2008.

The report revealed that the population of amphibians, birds, fish, mammals and reptiles dropped by an average of 52 percent between 1970 and 2010 but the worse impact was seen in freshwater species, which saw a decline of 76 percent over the same period, or almost double than the biodiversity loss experienced by land and other marine species. It also showed that the biggest declines occurred in tropical regions particularly in Latin America, which lost 83 percent of animals in four decades.

The drop in wildlife population is mostly blamed on man-made activities such as excessive emission of carbon dioxide, cutting of trees, pumping of groundwater, hunting and overfishing albeit invasive species and diseases also posed threats to wildlife population.

"If half the animals died in London zoo next week it would be front page news," said Zoological Society of London Director of Science Ken Norris. "But that is happening in the great outdoors. This damage is not inevitable but a consequence of the way we choose to live." 

Although the impact of climate change on wildlife species remains disputed until now, the Living Planet Report 2014 noted that the effects of the changing climate have become a growing concern and WWF officials put hope in a global effort that could curb global warming and its unwanted effects.

"Ambitious and focused negotiations over an international climate deal to be agreed in Paris next year are a clear opportunity to control, and hopefully reverse, the trends highlighted in the Living Planet Report," WWF-UK Chief Executive David Nussbaum said.

Among the animals that are seriously threatened by a collapse in their population include the forest elephants in Africa, which are threatened by habitat loss and poaching, and marine turtles whose numbers have dangerously dwindled because of the destruction of their nesting grounds and hunting.