Guardian: At 1.5C 90% of Coral Reefs will Die

Essay by Eric Worrall

But we already breached 1.5C.

Coral reefs are nearing extinction. 2026 must mark a turning point

Jason Momoa
Fri 17 Apr 2026 22.00 AEST

At 1.5C of global warming, up to 90% of coral reefs could be lost. The next few months could be a defining moment.

…

Our coral reefs are under severe stress. The planet has just experienced the most widespread coral bleaching event ever recorded, lasting 33 months into 2025. Scientists warn that at 1.5C of global warming, up to 90% of coral reefs could be lost. Ninety per cent. And 1.5C is not lingering in the distance – it’s extremely close.

Even if the world somehow hits its climate targets, reefs are still getting pummeled by plastic pollution, coastal development, agricultural runoff and overfishing. They’re so fragile. And when reefs weaken, coastlines get hit harder by storms and rising seas. Homes and jobs become exposed. Cultures and sacred places are put at risk. And the incredible range of underwater life found only in reefs – once it’s gone, it’s gone for good.

…

Through my work with the UN Environment Programme and the Global Fund for Coral Reefs, I’ve also seen how smart investments can lead to major change. Even a little bit of finance can go a long way to help people find new ways to earn a living without destroying nature, boost conservation of marine ecosystems and support communities in rebuilding sustainably after they’re hit by extreme weather.

These give me hope. But the hard truth is that we still lack the luxury of time to sit back and rely on what’s already happening. Climate change and unsustainable development are moving fast, meaning we need to move faster.

…
Read more: https://www.theguardian.com/commentisfree/2026/apr/17/coral-reefs-extinction-global-warming-jason-momoa

The problem with claiming 1.5C is a tipping point for coral extinction is we already passed 1.5C, and Coral has not experienced a 90% extinction.

Yale 360: We Briefly Crossed 1.5C But We Still Have Time to Reverse Climate Change

One of the UN articles linked by Jason claims the 2024 1.5C breach didn’t last long enough to count, so perhaps this coral scare is part of an ongoing effort to rehabilitate the 1.5C UN climate campaign.

5 13 votes

Article Rating

70 Comments

Inline Feedbacks

View all comments

Dave Burton

April 23, 2026 2:11 am

Jason Momoa! I guess since he portrayed Aquaman that makes him an expert on marine ecology, by the rigorous standards of the climate industry.

Global warming is no threat to coral reefs. Most coral thrive best in warmest water. Even the very warm southern Red Sea is dotted with healthy coral reefs (unlike the cooler Mediterranean). Reef locations are mostly clustered around the warm equator:

At 7:20 in this BBC video you can hear how wonderfully healthy the coral are in warmest part of the very warm southern Red Sea, off Eritrea:

https://www.youtube.com/watch?v=vSOLDf1a9dA&t=440

Here’s a great lecture by Professor Peter Ridd, about the Great Barrier Reef:

https://www.youtube.com/watch?v=gSSNXjPbpOY

Coral reefs are highly resilient, largely because coral polyps and zooxanthellae float around in the ocean. When conditions change in one place, becoming unsuitable for the organisms currently living there, other zooxanthellae & polyps will soon colonize it, and the reef keeps on growing.

Claims that coral are highly vulnerably to small changes in their conditions are based on lab studies which prevent that from happening, which is unrealistic.

Tom Abbott

Reply to Dave Burton

April 23, 2026 4:08 am

If an atomic bomb blast can’t wipe out corals, then CO2 has no chance of doing so.

AGW is Not Science

Reply to Tom Abbott

April 23, 2026 4:41 am

That was going to be my first reaction. Coral reefs are FRAGILE?! Try visiting Bikini Atoll, where nuclear detonations couldn’t wipe out the coral reefs.

Another actor I don’t need to hear from anywhere but the silver screen.

bnice2000

Reply to AGW is Not Science

April 23, 2026 2:11 pm

Not sure Jason so much acts, as just plays being himself.

Scarecrow Repair

Reply to Tom Abbott

April 23, 2026 7:21 am

Or the 400+ foot sea level rise just a few thousand years ago, or the comet which killed the dinosaurs.

bnice2000

Reply to Dave Burton

April 23, 2026 2:10 pm

And of course, the tropical oceans are self limiting when it comes to temperature, because of the evaporation cycle.

The Nino regions show no warming in 47 years.

ps.. I wonder how corals survived during the Holocene Optimum and other periods when the world was warmer than the current “tepid” period, barely a degree or so above the coldest period in 10,000 years. 😉

Dave Burton

Reply to bnice2000

April 23, 2026 9:01 pm

Prof. Ridd discussed that very thing, in his lecture. It wasn’t the temperatures which mainly affected the GBR during the Mid-Holocene Climate Optimum, it was the fact that the sea level was about a meter higher near Queensland and the GBR. Prof. Ridd explained what happened when the sea level decreased.

strativarius

April 23, 2026 2:36 am

In 1989 we had 10 years to save the planet.

It’s still here.

Tom Abbott

Reply to strativarius

April 23, 2026 4:11 am

The Climate Alarmists keep moving the goal posts.

It’s about all they can do.

MarkW

Reply to Tom Abbott

April 23, 2026 7:30 am

It’s the only exercise most of the get. They don’t do field work anymore.

KevinM

Reply to MarkW

April 23, 2026 9:28 am

Had the same thought when I read the AMOC Collapse part 98 story. A group of PhDs brainstormed, what work could we do that would never require us to stand up and walk away from our computers? Aha, a model study based on curve fitting insufficient data! Brilliant! Is there a snack machine nearby?

abolition man

Reply to strativarius

April 23, 2026 7:55 pm

In the 1960s there were 10,000 to 12,000 polar bears; today only 30,000 remain! Blame CO2!

Oldseadog

April 23, 2026 2:45 am

My BS alert went off at this paper so I clicked on the “most widespread coral bleaching event ever recorded” link and it looks horrendous. Then I read what the thing actually recorded and found that it was the temperature at which coral might bleach, and included lots of places where there are no warm water corals at all.

AGW is Not Science

Reply to Oldseadog

April 23, 2026 6:34 am

“Might,” “Could,” “May,” ad nauseum.

The foot soldiers of the Climate Waffe.

Godzilla *might* appear someday too. 😆😅🤣😂

Oldseadog

Reply to AGW is Not Science

April 23, 2026 6:52 am

If “ifs” and “ands” were pots and pans there’d be plenty of work for the tinkers.

abolition man

Reply to AGW is Not Science

April 23, 2026 7:57 pm

I believe you misspelled “waffle!” At least it makes more sense.

DD More

Reply to Oldseadog

April 23, 2026 11:09 am

oldest coral origins date back to the Ordovician period (488–444 million years ago), with early, extinct rugose and tabulate corals appearing during this time. The earliest known diverse fossil reef is the 480-million-year-old Chazy Fossil Reef in Vermont, USA, showcasing early reef-building,

Key Findings (500 Million Years Ago to Present)

Drastic Temperature Swings: For most of the past 500 million years, Earth was in a “warmhouse” or “hothouse” state, too hot for polar ice caps.
The “Hottest” Periods: Temperatures were exceptionally high during the Cretaceous and early Eocene periods, with tropical temperatures extending toward the poles.

Coral still taking care of themselves.

Right-Handed Shark

April 23, 2026 3:13 am

Momoa needs to watch this on a loop until he ‘gets it’

Scissor

Reply to Right-Handed Shark

April 23, 2026 3:45 am

Sounds like Momoa should cut down on the reefer.

Dave Burton

Reply to Right-Handed Shark

April 24, 2026 3:21 pm

Absolutely! And everyone else, too!

That’s Dr. Jennifer Marohasy’s video, documenting the investigation which she and Dr. Walter Starck conducted of a supposedly (according to a paper in Nature) mostly dead coral reef. The healthy, living coral there is spectacular, and so is the photography!

“Just because something is published in Nature, it doesn’t mean that it’s wrong.”
– Professor Martyn Poliakoff

Dave Burton

Reply to Dave Burton

April 25, 2026 4:31 am

Clarification:

I wrote, “according to a paper in Nature,” and at 6:59 in the video, Dr. Marohasy says, “The branch structure I’m defining is specific to the genus Acropora. Yet according to a scientific report, published in the prestigious journal Nature, there are no longer any Acropora at Stone Island. According to the current consensus, there were Acropora when Kent was photographing more than a hundred years ago, but since 1994 there are, and I quote, ‘no living Acropora colonies.’ They’re dead, along with other corals, now covered in mud.”

Technically, the (Clark, 2016) paper was published BY Nature, not IN Nature.

It used to be that Nature was just a single journal, but for several decades they’ve been dividing and expanding. Even before their 2015 merger with Springer, they were already publishing more than 80 journals, including Scientific Reports, which is the journal that published (Clark, 2016).

On 18 Nov 2019, The Grauniad published a hit piece by Graham Readfearn, claiming that this video misrepresents the Clark paper. They reported that the paper’s lead author, Tara Clark, said, “we never claimed that there were no Acropora corals present [at Stone Island] in 2012.”

That’s deceptive. Clark’s paper said, “very little sign of coral re-establishment was found at Stone Island,” and it later said that, “in 1994, no living Acropora colonies were found at either location and the majority of the large faviids that featured so prominently at Bramston Reef in c.1890 were dead, covered in algae and/or mud.”

Those two statements obviously imply that there were few if any living Acropora colonies there, which is inconsistent with the large, healthy Acropora colonies filmed by Drs. Marohasy and Starck.

Dr. Marohasy also has an informative webpage about Bramston Reef and the healthy coral colonies which they found there:
https://jennifermarohasy.com/2019/05/corals-other-side-of-mud-flat/

1saveenergy

April 23, 2026 3:19 am

[“At 1.5C 90% of Coral Reefs will Die”]
Wot a load of luck-balls !!

Shame is that people will take the word of an idiot actor, in preference to someone like Professor Peter Ridd.

Tom Abbott

Reply to 1saveenergy

April 23, 2026 4:13 am

The Climate Alarmists repeat this nonsense about every six months.

Along with their other memes.

Bill Toland

April 23, 2026 3:22 am

Jason Mamoa could have claimed that 110% of coral reefs will die. It’s just as realistic as his claim of 90%.

Eng_Ian

Reply to Bill Toland

April 23, 2026 4:14 pm

And most of the believers would have no problem with 110% dying.

Math(s) is racist.

Phillip Chalmers

Reply to Bill Toland

April 23, 2026 8:39 pm

Why not? He is a Guardianista

Dave Burton

Reply to Bill Toland

April 24, 2026 3:27 pm

Unfortunately, such innumeracy is widespread. 110% coral die-off is no more nonsensical than a 1000% drug price reduction.

feral_nerd

April 23, 2026 3:52 am

Climate psychosis stems from a fundamental misunderstanding about the natural world, its many systems, and the web of life inhabiting it. The chronic worriers believe the earth is a fragile thing that wilts under the mildest stress, a silly belief easily rebuked. If this were true, life would have died out eons ago of natural causes, or never have come into being. In reality, Earth and its living inhabitants are fantastically resilient. They have to be to survive in a world that changes constantly and is periodically subject to random traumas.

Climate psychosis is a perceptual disorder, like so many other fear-based belief systems.

RickWill

April 23, 2026 3:53 am

Both Grok and MS Copilot “know” the ocean surface cannot sustain more than 30C due to convective thermo-regulation.

Global Warming™ is dead. UNIPCC runs out of money by 2028 and AR7 is going nowhere because the oceans of the SH have stopped warming. There is no spin that can counter a whole hemisphere losing heat.

The latest catchphrase in Australia is “drill baby drill”. Australia is the most diesel dependent economy in the G20 and makes enough of it to run one farm. The rest is imported – totally reliant on the rest of the world. POTUS Trump has kindly donated a ship load of diesel so Australian farms can get the winter wheat sown.

Tom Abbott

Reply to RickWill

April 23, 2026 4:18 am

It looks like the Climate Alarmists are running up against things their CO2 theory can’t explain in the Southern Hemisphere.

I eagerly await their attempts to explain these things away.

Trump is out there collecting Iranian oil tankers. I’m glad he is helping Australia out.

Tom Abbott

April 23, 2026 4:05 am

We also breached this so-called tipping point in the 1930’s.

Coral Reefs did not disappear then.

Then, after that, the temperatures cooled by about 2.0C down through the 1970’s.

Recently, temperatures in 2024, warmed to the level of the 1930’s. Today, temperatures have cooled by about 0.5C from the temperature high point of 2024.

What happens next?

Well, after the 1930’s high point, the temperatures cooled by about 2.0C. This also happened after the temperature high point in the 1880’s.

So, if history is any guide, the temperature today should continue to cool.

CO2 has nothing to do with it.

DipChip

April 23, 2026 4:27 am

“At 1.5C of global warming, up to 90% of coral reefs COULD be lost”.

The USA COULD have another record setting Hot summer like 1936, Imagine the hype, followed by another 25 years of 21st century weather.

KevinM

Reply to DipChip

April 23, 2026 9:36 am

That’s one of the real possibilities that scares me –
It can get 1930’s hot for a decade without confirming agw, that seems to be something that can ‘just happen’. Then I’d have to wait another decade feeling dumb until the 1940’s temperatures set in.

MarkW

Reply to DipChip

April 24, 2026 9:27 am

During the Holocene Optimum temperatures were several degrees warmer than today, and stayed that way for thousands of years. Coral didn’t die off.

Bill Toland

April 23, 2026 4:31 am

I am old enough to remember when the Guardian was a decent newspaper. The Guardian seems to become more and more detached from reality with every passing year. When it comes to the climate, the Guardian appears to have jumped the shark completely.

Ed Zuiderwijk

Reply to Bill Toland

April 23, 2026 5:21 am

It’s called George Monbiot Syndrome, GMS.

Bryan A

Reply to Ed Zuiderwijk

April 23, 2026 5:56 am

I thought that was the Moneybot syndrome. Anything for Clicks and thereby Money.

KevinM

Reply to Bill Toland

April 23, 2026 9:40 am

Here you are on the Internet… what could the Guardian write today for you to read tomorrow morning that you could not know about before the literal printed paper lands on your doorstep? They are selling keepsakes for people who need physical evidence that they exist – written without disdain, I like a print copy of the headline that says my favorite sports team won.

Ed Zuiderwijk

April 23, 2026 5:15 am

Methinks we should send Jason a few brochures advertising scuba diving holidays on the GBR.

strativarius

Reply to Ed Zuiderwijk

April 23, 2026 5:47 am

If only he could be returned to Stargate Atlantis.

Bryan A

April 23, 2026 5:48 am

Are Coral Reefs so tenuous that they can’t survive an ever changing climate?
Are Coral Reefs a recent phenomenon or have they been around for thousands of millennia?
(Coral has existed for 500MY!)
Haven’t Coral Reefs survived repeated Glacial/Interglacial cycles for at least the last 880,000 yrs? (Each and every one since the closing of the Panama Isthmus 3.4mya)
Haven’t Coral Reefs survived even warmer temperatures and higher CO2 levels?
(Both Temperatures of up to 9°C warmer and CO2 levels of over 3000ppm have existed)
Didn’t Coral Reefs survive being inundated from Melt water Pulse 1A?
(Sea Level rise was at a rate of 40mm – 60mm/yr or .12-.2″/yr … 1.2′ – 2′ per decade)

John Greer

April 23, 2026 6:09 am

Are Corals Dying From Global Warming? No. Like most things, corals grow faster in warmer temperatures. Sample data from 49 reefs shows 5 times greater calcification rate at 29 C than 23 C annual sea surface temperature. See chart.

Len Werner

April 23, 2026 7:15 am

It is an interesting phenomenon that an actor can reach adulthood and still be so ignorant, and not know it–and that it might be wise to just shut up and not prove it. That must be an important quality of narcissism. Check the Jurassic–the geologic era, not the movie–and get back to us.

I did check his bio; it is starkly obvious that his qualifications for stating anything about coral reefs beyond ‘Gee they’re pretty but I got scratched by one once on a Baywatch set’–is 0.00.

Graemethecat

Reply to Len Werner

April 24, 2026 12:18 am

Actors are paid to dress up and spout words written for them by scriptwriters. They have nothing worthwhile to say about anything other than drama.

SwedeTex

April 23, 2026 7:19 am

Actors. By definition they use illusion to create reality and are so dumb they have to have others write the words they say.

Mr.

April 23, 2026 7:20 am

Somebody send Jason the observed, documented experiences of the Bikini Atoll coral reefs obliteration by atomic bonds testing in the 1950s, and their astonishing full recovery to full size just ~65 years later.

Also in the 1950s, our TVs, radios, newspapers and magazines were bombarded with multiple ads that intoned –
Scientists [always in white coats] warn that unless [fill in what we are doing / not doing], up to 90 % of [very important things] could be lost.
[SO SEND US YOUR $$$ NOW]

John Hultquist

April 23, 2026 8:41 am

Jason Momoa? What happened to Al Gore in his “ManBearPig” persona?
It seems the current era of men-have-beards requires a propagandist with unruly facial hair.

KevinM

Reply to John Hultquist

April 23, 2026 9:45 am

Someone must have told Gore to be quiet for another year and a half.

Sparta Nova 4

April 23, 2026 9:01 am

Funny. The nova definition of climate (pirated from micro climate definition when satellites started gathering data) is a 30 year average of weather.

So the past 3 years define the 30 year average?

Hmmmmm…..

Also, coral bleaching is not coral death.

KevinM

April 23, 2026 9:18 am

At 1.5C 100% of everything mortal will (eventually) die. 4000+ years of written history and scientific progress and I have no evidence of a single human that’s been here the whole time.

KevinM

Reply to KevinM

April 23, 2026 9:22 am

Hey waitaminit isn’t most of the coral in the reef already dead? Like the top surface is stony shells containing live critters and the interior is stony shells containing formerly-alive (aka dead) critters.
It’s a surface area vs volume calculation on an irregular shape that requires sonar and computer scripts to execute.

Phillip Chalmers

Reply to KevinM

April 23, 2026 10:58 pm

Spot on. Even the chalky white looking coral at the surface is not dead; it has just shed its coloured passengers (algae which are sometimes stressed by changes in salinity, light, warmer or colder water) and is taking more on board which thrive better at that particular time and place and weather conditions.

Graemethecat

Reply to KevinM

April 24, 2026 12:21 am

I remember being told by my Biology teacher ca. 1974 that the GBR was doomed by the proliferation of the Crown of Thorns starfish.

KevinM

Reply to Graemethecat

April 24, 2026 8:45 am

GBR = Great Barrier Reef
I first thought GBR = Great BRitain and pictured starfish crawling out of the ocean with machine guns and flying WW2 bomber jets made of seashells.

MarkW

Reply to KevinM

April 24, 2026 9:29 am

With the possible exception of a couple of plants, nothing has survived for that time period.

Gunga Din

April 23, 2026 10:56 am

Jason Momoa played Aquaman in a number of movies I really liked.
But him speaking as some kind of expert on coral reefs?
Reminds of those commercials where someone “saves the day” and is asked if he’s a doctor (or whatever) and responds, “No. But I stayed at a Holiday Inn Express last night.”
Also a similar line in a different commercial (I don’t remember what it was for), “No. But I play one on TV.”

Westfieldmike

April 23, 2026 12:23 pm

It’s a fact that corals love warm water, they thrive in it.

Bob Armstrong

April 23, 2026 1:16 pm

Why are corals so stupid they keep choosing tropical seas ? There’s plenty of cold water around .

Leon de Boer

Reply to Bob Armstrong

April 23, 2026 7:56 pm

That is actually the funny fact corals can’t survive in cold water because they depend on symbiotic algae (zooxanthellae) that require warm, sunlit water to photosynthesize and provide food.

So the actual scientific studies you would think would be studying zooxanthellae. Zooxanthellae Type D, are more resistant to high temperatures. So if the waters are getting warmer what you can expect is the zooxanthellae Type D to thrive and coral species that can utilize them will become dominant.

Acropora millepora, Porites lutea and a number of others readily do it. So the composition of the reef may change but it will not die. There will be winners and losers on species that rely on the coral but that is natural selection at play.

So the title should be coral reef may change but die is so much more emotive by the leftards.

Graemethecat

Reply to Bob Armstrong

April 24, 2026 12:22 am

There are corals living in deep Arctic waters.

Edward Katz

April 23, 2026 2:04 pm

Since when do alarmist outlets like The Guardian worry about factual accuracy? If the facts refute their claims, just message them a bit by adding more potential doomsday scenarios to the mix and downplay or completely ignore their previous inaccurate claims. Canada’s CBC is good at these sorts of stunts as well. When the predicted huge decline in polar bear populations was proved to be false, the network switched its extinction threats to types of seals and penguins. If this proves to be off-target, it’ll quickly find something else.

bnice2000

April 23, 2026 2:17 pm

Great Barrier Reef bleaching most often occurs during El Nino events when the sea level in the region drops and exposes the near surface coral to too much direct sunlight.

The coral critters don’t like that, so they take a short holiday.

Here is the SST in the GBR region at the 2015 bleaching event