Between 1970 and 2010, the planet lost 52 percent of its wildlife, according to data collected by the World Wildlife Fund and the Zoological Society of London. That’s an alarming statistic even while certain creatures like otters, wolves and buffalo make a comeback.

The Living Planet Report released last week is based on an index that measures 10,380 representative populations of mammals, birds, reptiles, amphibians and fish. The report said the number of land and marine animals both plunged by 39 percent in less than half a century, while the worst loss occurred to freshwater animals at 76 percent.

Deforestation across every continent accounts for much of the decline in numbers of land animals such as elephants, gorillas and big cats that depend on lush forests for food and habitats in which to mate. The poaching of animals is another cause of this disaster.

Overfishing has devastated the number of marine animals faster than they can replenish themselves. Whales, sharks and dolphins are threatened as much as small fish, as fishing nets that are miles long drag indiscriminately across the ocean floor. Freshwater fish are also in steep decline as dams and pollution that disrupt habitat take a toll.

Coral reefs are succumbing to diseases caused by industrial farm runoff that empties into oceans from damaged rivers. Oxygen-depleted zones hundreds of miles wide are popping up in the world’s oceans. Consequently, bird populations decline as their feed stocks die off.

The report says that 1.5 Earths are needed to maintain humanity at the rate that it consumes resources for “food, fuel and fibre, the land we build on and the forests we need to absorb our carbon emissions.” World leaders need to take seriously the WWF’s call for international talks on sustainable development goals and actions, including on climate change, that will reduce the depletion of resources and the harm to Earth’s wildlife.

Changing mankind’s patterns of consumption, waste and pollution will not only transform economies arguably for the better, but it is also the only rational thing to do on a planet with a growing human population and finite natural resources.

Editorial by the Pittsburgh Post-Gazette