Are Coral Reefs Doomed Within the Next Few Years?

A recent science news report stated that, according to a study signed by 160 researchers, the destruction of coral reefs is now almost certainly irreversible. The report says that most coral reefs will die once global warming exceeds 1.5 degrees Celsius compared to pre-industrial levels.

At present, the climate has warmed by 1.4 degrees, according to scientists, which means that the temperature leading to the irreversible collapse of reefs is expected to be reached within the next few years. When that happens, for example, the ice sheets of Greenland and West Antarctica are likely to collapse.

And that’s not all — according to the lead author of the report, Tim Lenton, one of the tipping points involves the collapse of existing ocean currents, which would have catastrophic consequences. If this were to occur in the ocean circulation system known as the Atlantic Meridional Overturning Circulation (AMOC), it would disrupt the global climate and, among other effects, cool the winters of Finland and the rest of Europe.

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I wanted to highlight this topic because the report provides a clear prediction — one that will be fascinating, if admittedly frightening, to follow in the coming years. It’s especially intriguing because the timeframe mentioned is “in the next few years,” which to my ears sounds more like less than ten years rather than more. At the very least, it doesn’t imply waiting several decades, as shown by the chart published a couple of years ago by the University of Berkeley, which I’ve copied below.

So, I’ll try to remember to follow this issue in the coming years — and to report on it here in this blog, unless I become too senile before the coral reef catastrophe actually happens.

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Before that, however, it’s worth recalling a study from last year which found that coral reef restoration can accelerate the recovery of coral cover and carbonate production so rapidly that the reefs’ net carbonate budgets resemble those of healthy reefs within just four years. And this occurs under the current climate, which is already 1.4 degrees warmer than in pre-industrial times.

And that’s not all — this year another study was published showing that there are also coral reefs that are recovering. At least some can be found in the Chagos Archipelago, where coral cover on both the fore-reef and the lagoon increased by 59–67% after several years of bleaching.

It remains to be seen, however, whether this change of direction is only temporary — or whether it will prove to be permanent.

Previous thoughts on the same topic:
Climate Warning Signs Were There 130 Years Ago – If Only We Had Noticed
Diverging Findings in Antarctic Ice Sheet Research
Big Deal in the Cold North: Finland vs. Canada

The original blogpost in Finnish:
Tuhoutuvatko koralliriutat lähivuosina?