(contributed by Emma Seddon)
Carbon monoxide gathers deadly force slowly . So slowly that you don’t realise anything is happening. You get a bit irritable, then a bit woozy, then a bit lethargic. By the time you start feeling nauseous, it’s too late. All you want to do is lie down and have a little rest, to clear your head. You never wake up.
Carbon monoxide, among other gases, was (and still is) a big problem down mines. Before sophisticated technologies to both detect noxious gases and to remove the risk from them, miners used to take caged canaries into mines with them. Why? Because if toxic, undetectable gases like carbon monoxide were present, the canary would succumb before the miners . A dead or suffering canary would give the miners enough warning time to get out of the shaft before the gaseous effects took hold of them. Cruel, but effective. So effective, in fact, that mine canaries were only phased out in the UK in 1986 .
The world at large is currently in very real danger from carbon dioxide and other greenhouse gases. We’ve got a form of canary which is currently warning us strongly that things are imminently about to get deadly for us. Unlike the miners of old, however, we’re completely ignoring it. I speak of coral bleaching . Hundreds of kilometers of coral are dying, and it’s undoubtedly due to human action. We’ve had, in all fairness, multitudes of natural warnings about the danger we’re putting the planet in through our actions - but coral bleaching is one of the clearest (and deadliest) signs yet. It indicates in the strongest manner possible that our actions are not sustainable, that the planet cannot tolerate them - and that the consequences of our wholescale environmental disregard are about to catch up to us with deadly force. Yet we’re turning a blind eye. Our coral canary is lifeless in the cage, and we’re continuing to mine.
Coral bleaching is essentially the death of a coral reef. It occurs when corals are stressed, and jettison the symbiotic algae within their tissues. In human terms, this is akin to them sloughing off their skins, leaving them skeletally vulnerable. Unsurprisingly, they die swiftly thereafter, leaving behind only their white, bone-like structures. Coral stress is caused by many things, including changes in light levels and the availability of food - but scientists are 99% certain that the recent, wholescale coral bleaching phenomenon is caused by rising water temperatures .
Coral bleaching is not just the death of the poor corals. It also spells disaster for the many, many species which live in and around coral reefs. Coral reefs are complex habitats , providing sustenance and shelter for an astonishing 25% of marine life. They’re enormously important for the preservation of more oceanic species than we may think. Without the coral reefs, it is likely that a chain reaction would cause mass oceanwide extinctions - and that’s without taking into account the widespread impact of the climatic conditions causing the coral bleaching. Coral bleaching is extremely serious. So it’s very, very worrying for marine biologists that the coral bleaching we’re currently seeing is far and away the biggest and most serious bleaching event ever seen.
Thousands upon thousands of kilometers of the Great Barrier Reef are now bleached - an estimated (and horrific) 93% . Many entire colonies have been obliterated , leaving the species which rely upon them extremely vulnerable . Marine biologists - openly devastated by and angry about the phenomenon  - state that the coral are unlikely to recover even if action is taken on climate change, and if no action is taken, we could see the complete extinction of coral within our lifetimes. And this would not only mean the extinction of coral, but the extinction of an incomprehensibly enormous swathe of marine life.
Horrible, undoubtedly, for the oceans - but why should this bleaching be a ‘canary’ for humans? Well, scientists are more or less unanimous in stating that coral bleaching is caused by a rise in oceanic temperatures (itself caused by anthropogenic global warming). Warmer water means less oxygen, which means that not only coral (and all which relies upon it) is under threat, but everything else in the warming oceans as well. From a lesser economic point of view, coral bleaching is going to deliver a pretty hard blow to the Australian tourist industry (for which coral diving draws in millions of dollars each year). From a more serious, human life point of view, the loss of ocean species spells wholesale disaster for human communities around the globe. We rely more heavily than we realise upon oceanic resources. Over 100 million people are directly dependent upon coral reefs in one way or another for their survival , and many hundreds of millions more depend upon the sea for sustenance. Mass marine life extinctions spell bankruptcy at best and starvation at worst for millions of human communities worldwide. No amount of contingency plans and personal cover  can help you when the food and resources simply aren’t there any more. Clearly we should be concerned about coral bleaching for its impacts upon the wildlife and planet - but if we can’t muster any sympathy for that, then surely we can generate a little concern for our own impending predicament?
Apparently not, if the Australian government’s reaction is anything to go by. Although paying lip service to the problem, Australia remains committed to coal mining. Fossil fuels and the like are directly responsible for the death of the Great Barrier Reef - yet Australia recently wholeheartedly approved plans for the world’s largest thermal coal mine to be created in Queensland’s Galilee Basin . The Carmichael coal mine is estimated to ultimately produce more fossil fuel emissions per year than New York city . To push a not inappropriate metaphor, that’s an awful lot of dead canaries. And that’s before we’ve even touched upon the ocean dredging and spoil contamination the mining itself would create. The government only reluctantly agreed not to dump dredge spoil on the dying Great Barrier Reef itself after intense pressure from conservation groups - demonstrating the kind of astonishing, pig-headed blindness we’re up against.
How can we save the Great Barrier Reef? Sadly, we probably can’t. It’s too late for that particular canary. But we can take action now to prevent things from getting any worse. By cutting fossil fuel consumption and generally taking a bit more care of the planet, we could see the oceans beginning to recover for our children and our children’s children in a few decades. Unfortunately, if the actions of the Australian and other governments are anything to go by, it looks like we may all shortly be succumbing to carbon monoxide - both metaphorically and literally.
-  “Carbon monoxide poisoning”
-  “Why did they put canaries in coal mines?”
-  “1986: Coal mine canaries made redundant”
-  “What is coral bleaching?”
-  “Impacts of global warming on corals”
-  “Why Are Coral Reefs Important?”
-  “Great Barrier Reef: 93% of reefs hit by coral bleaching”
-  “Great Barrier Reef: devastating images tell story of coral colonies’ destruction”
-  “Coral bleaching distressing Great Barrier Reef wildlife”
-  “Mourning Loomis Reef - the heart of the Great Barrier Reef’s coral bleaching disaster”
-  “Bleaching Impacts”
-  “Health Insurance”
-  “Australia Is Letting The Great Barrier Reef Die Over A Lot Of Coal”
-  “Coal from Carmichael mine ‘will create more annual emissions than New York”