The World Wildlife Fund (WWF) is warning that half of all natural World Heritage Sites are in direct danger from industrial activities such as mining, oil exploration and illegal logging.  That is especially true of the Great Barrier Reef, which is currently undergoing a record bleaching event.

"Despite the obvious benefits of these natural areas, we still haven't managed to decouple economic development from environmental degradation," WWF director general Marco Lambertini.  "Instead, too often, we grant concessions for exploration of oil, gas or minerals, and plan large-scale industrial projects without considering social and environmental risks."

The 229 natural and mixed sites include national parks and nature reserves, forests, coral reefs, islands and coastal areas.  The WWF's new report says 114 of them are threatened - and these sites provide food, water, shelter and medicine to over 11 million people.  That's more than the population of Portugal.  These sites include Germany's Wadden Sea, the Grand Canyon in the US, Machu Pichu in South America, and the Belize Barrier Reef off Central America.

But bleaching damage to the Great Barrier Reef is now believed to be much worse than thought.  A recent James Cook University study revealed that as much as 95 percent of the northern section of the Reef is "severely bleached".  The immediate cause is global warming, but a new threat is on the horizon, and things aren't looking good for the Great Barrier Reef.

Last weekend, Queensland Premier Annastacia Palaszczuk issued permits for the controversial Charmichael coal mine that marine biologists fear could choke out portions of the reef with pollution.  The Australian Conservation Foundation is calling it "grossly irresponsible" to allow the Indian mining company Adani to extract an estimated 60 million metric tons of coal and ship it to Asia through the Reef.  Critics warn the mining project could lead to some five million tons of dredged soil and sediment dumped directly inside the Great Barrier Reef Marine Park.  That sediment would cloud the water, blocking out the sunlight corals and seagrasses depend on to survive.

"The (United Nations) World Heritage Committee is clear and definitive that extractive activities should not occur in World Heritage sites," WWF global conservation director Deon Nel.  "It has consistently maintained a position that oil, gas and mineral exploration and exploitation is 'incompatible with World Heritage status'."

But even if every single gram of coal is safely extracted and shipped, it's still coal - and coal-fired power plants is the world's top source of carbon dioxide emissions, the primary cause of global warming.  Burning coal is also a leading cause of smog, acid rain, and toxic air pollution.