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Reefs Passed the Tipping Point Long Ago.


Have the world’s coral reefs already passed a tipping point? That is the headline of an article in Grist this week concerning the latest circumtropical coral bleaching event now taking place. It’s a sad question in several respects.

First, it’s sad because it focuses attention on the tipping point, some strange sort of milestone along the path to degradation that our ill-considered human activities are propelling the planet along. Are we going to remain unconcerned until the tipping point is reached, and what if we miss the tipping point – does that mean we don’t need to bother being concerned because it is too late?

It’s sad also because it asks the question of reefs as if their problems are somehow separate from those of other systems on the planet.  Perhaps we can decide that, yes, reefs have now reached the tipping point, but, not to worry, because grasslands, and temperate forests, and marine kelp forests have not yet done so.

It’s also sad because it puts us in the role of spectators rather than perpetrators. We can remain outside the biosphere, certainly outside the marine system, objective, rational observers, calmly keeping score as the world dissolves into chaos around us.

This year’s bleaching of the 2300 km long Great Barrier Reef is well documented, and similar intensities of bleaching are occurring at many other locations around the world in this 4th circumtropical bleaching event.
Image from press release issued jointly by AIMS, GBRMPA and the Australian government.

Some History

In 1982-3, coral reefs first responded to warm sea temperatures during a severe el Niño by mass coral bleaching on a regional scale (the Pacific coast from Costa Rica south through Panama and Colombia, and out at the Galapagos Archipelago). They have been bleaching intermittently ever since, with the first circumtropical event occurring in 1997-8. The frequency of bleaching events has been increasing. The cover of living coral on the world’s reefs has diminished.

Scientists have done the research to confirm what is happening and why. They have made projections into the future of what will happen if we continue to warm the planet. IPCC has reported the science, stating in 2018 that if the world managed to hold warming to +20C, we’d expect to lose 99% of coral reefs worldwide – meaning that coral-dominated biotopes would essentially cease to exist. Even at +1.50C, the aspirational goal from the Paris Accord, losses by 2100 were expected to be 95%.

Scientists have also done the research to document the considerable value to humans of coral reefs, as well as to quantify the numbers of humans directly dependent on coral reefs for their livelihoods, their food, or for protection from ocean storms. Trillions of dollars worth of value provided by living reefs.

None of it seems to make a scrap of difference because, despite the repeated bleachings, and despite the evident loss of coral cover, and despite the increased information concerning consequences, the world goes merrily on, burning fossil fuels and increasing the concentrations of greenhouse gases in the atmosphere. The bleachings of coral reefs are just nature stories – something beyond the lives of watchers of the evening news – something a bit less heavy than the usual shootings, wars, rapes and pillaging that seem to occupy us most of the time.

Our Place on This Planet and the Real Tipping Point

If the mass bleachings have done anything, it is to reveal how hopelessly disconnected the first world is from the natural world. And how selfishly we cling to our energy-intensive, polluting way of life. Our economists continue to teach about the need for perpetual economic growth. Our demographers document the growth of our out-of-control population, but don’t bother to explore what it might take to slow, stop and reverse. Social scientists and internationalists concerned with the extent of human suffering in the world preach sustainable development to raise living standards among those suffering the most while conveniently ignoring the fact that reducing the consumption of the wealthy (countries as well as individuals) is the only way development across this planet can ever be equitable and sustainable. And the marketplace, that divine construction of our consumer economy, continues to encourage ever more consumption of stuff we do not need. This planet cannot sustain a population of 8 billion people living ‘western’ lifestyles – the coral reefs are just the first obvious casualty of our plundering ways.

I recognize that there are individuals among us first world people who do see what we are doing. They try to live more sustainably, and often commit themselves to working to influence others. They are making a difference illustrated by the fact that the concentration of CO2 in the atmosphere is now growing linearly rather than exponentially. I commend them, and hope that their numbers and influence grow. But the forces allied against them – corporations and individuals that continue to put personal profit ahead of all else, our peculiar belief that accumulating wealth = success = happiness, and political and tax structures that reward wealth accumulation – and our natural tendency to continue behaving as we have always behaved all conspire to limit their effectiveness. Never mind our unrealistic faith in the permanence of the world as we know it. That it has taken 30 years for the nations of the world to commit to an eventual phasing out of use of fossil fuels – a commitment still being resisted by back-tracking corporations and governments – shows just how incapable we are of making pragmatic, sensible decisions that would benefit us all.

If we want to know the date for the tipping point for coral reefs, we need to look behind us rather than into the future. One could answer Grist’s question by saying the tipping point was passed back in 1983 because that is when the writing was on the wall. Our activities had warmed the planet sufficiently by 1983 that a strong el Niño could turn thousands of kilometers of tropical sea surface into an environment inhospitable to the delicate partnership between corals and their algal symbionts.

With hindsight, that was the point at which reefs worldwide tipped from having an optimistic to a pessimistic future. If we continued to warm, as we clearly have, reefs would bleach again and again, until the frequency of bleaching in any given geographic area would become too quick to permit recovery. (That frequency is somewhere between once a decade to once every 30 years, depending on whether one measures recovery as return to previous levels of abundance of coral, or return to previous levels of abundance and species diversity.) Once a reef’s coral biota shifts to becoming both less abundant and less diverse, the complex, interconnected, dynamic, hugely diverse, living wonder we call a coral reef is tumbling down a path toward something a whole lot less wonderful. Since 1983, we have continued to march dimly forward like lemmings towards the metaphorical cliff while dutifully reporting each bleaching, each more detailed prognostication about the future. And the reefs worldwide are less wonderful than they once were.

Even further back in time, somewhere in the 1950’s, there is another tipping point. That is the point at which our global economy began its exponential increase in use of energy and concomitant release of greenhouse gases to the atmosphere. That is the point at which our activities began to rapidly change the composition of the planet’s atmosphere and therefore, its weather. That is the point at which our hubristic failure to see ourselves as part of the living planetary system really began to have critical implications for our future well-being, as well as for the lives of countless other species including corals. And that is why we call the modern age of this planet the Anthropocene. Not anything to be proud of.

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