That’s it for corals.
The IPCC has gone full apocalyptic: “Coral reefs would decline by 70 to 90 percent with warming of 1.5°C…” And this catastrophic prophecy will unfold sometime around 2040. (See the graph).
The IPCC is practically holding the Great Barrier Reef Hostage. Things are so dire, the Financial Review has just declared that the next election is the Great Barrier Reef election.
In the game of fine-tuning the carrot and stick, it’s all bad, but there is hope.
Right now the reef covers 348,700 km². And if we are good boys and girls we might only lose 243,000 km²:
Scientists say Australia has a chance to save 30 percent of the Great Barrier Reef if immediate global changes are made to stop temperature rises.
This news will come as a shock to corals on the Great Barrier Reef which are obliviously living across a range of 2,000 kilometers and a span of five degrees Celsius from 27 to 32°C.
But these are magic numbers apparently, and half-a-degree hotter (which is all we are talking about) it will be 27.5 to 32.5°C, which is numerology hell where baby corals go to die.
You and I might think that corals might just emigrate since they shed sperm and eggs in mass spawning events visible from space and have 112 sites known to reseed all damaged areas. But what would we know?
And what would a dumb coral know – possibly something after 200 million years of climate change, most of which was hotter.
Corals survived the rock that killed the dinosaurs. They survived Toba, the supervolcano that left a crater 100km long.
Corals survived a 125m sea level rise at the end of the last ice age. And they survived the ice age — and the fifteen before it.
They also survived the super cyclones that have been hitting the coast of Queensland for the last 5,000 years and there is no sign that storms are getting worse. (see Nott 2001 and Hayne 2001.)
Who knows what handy genes corals carry after 200 million years of climate change?
At least one research team says corals already have the genes to survive another 250 years of warming.
Corals survive across a five-degree range:
The IPCC is going for the full wipe out.
University of New South Wales climate scientist Sarah Perkins-Kirkpatrick says “virtually all” coral reefs would start dying off if global temperatures increased by 2C. — The Australian
…whereas more than 99 percent would be lost with 2C.”
Corals survive massive sea level change
Sea levels have been falling in Queensland for 3,000 years. (Lewis et al 2012) Currently, they are rising globally by about 1mm a year according to 1,000 tide gauges.
However, as the seas return to where they have been scores of times before, apparently corals will be wiped out, just like they never have been.
Corals have been around through all this:
We are worried about a half a degree…
Note that these are polar temperatures on the graph. But that’s the thing, if tropical temperatures had this kind of volatility, how could corals have made it this far?
Instead, because the tropics have their own evaporative air conditioner they don’t get too hot, and as long as we are not in a Snowball Earth scenario, they don’t get too cold either. Water evaporates quickly above 30C.
So the tropics expands and shrinks as the climate changes but it doesn’t go away, and nor have corals.
Things the ABC BBC and CBC won’t tell you about coral reefs:
- In some places, ocean acidification happens every single day. No biggie.
- Fish behave better when artificial tanks mimic these natural daily swings.
- A bit less alkalinity is good news for hundreds of marine species.
- Some coral reefs thrive in a more acidic ocean
- There is a big safety margin: farmed fish seem to cope fine with CO2 levels that are even fifty times higher than today.
- We only discovered coral bleaching in the 1980s but it’s probably been going on for millions of years.
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