In this interview, Dr Peter Ridd appeared on Outsiders – Sky News Australia to discuss the IPA’s research on the Great Barrier Reef.
All media appearances posted onto the IPA website are directly related to the promotion and dissemination of IPA research.
Below is a transcript of the interview.
Rowan Dean:
Joining us now is adjunct fellow at the Institute of Public Affairs, great friend of this show, Peter Ridd. Peter, great to see you. Last time I saw you, you and I were diving off the Great Barrier Reef. It was a great day, and we had a terrific time.
I’ve got an article in The Spectator Australia this week which you were instrumental in helping put together from Bill Johnston and David Mason-Jones. And it’s a fascinating story, which I will let you tell. But basically tell the setup about how we now suddenly have discovered this amazing source of data from 1871, very accurate, very scientific about the water temperatures in the Great Barrier Reef way back then. Tell us the story, Rita, and your role in it and how it came about.
Peter Ridd:
Well, of course, everybody knows that the Great Barrier Reef, the water is so hot that the corals are almost boiling up there, and it’s increased in temperature over the last 150 years. But of course there is no data, you’d think, from the water temperature 150 years ago. But actually, there is. And this is what David Mason-Jones, but mainly Bill Johnston were able to find in an archive. And it dates back to 1871. And the Royal Observatory and the Royal Society of Victoria decided to send an expedition, the first major scientific expedition by the fledgling Australian states to observe an eclipse right at the top of Cape York Peninsula. They hired a steamer, which sailed all the way up the coast from Sydney up to the tip of Cape York to observe this eclipse. And guess what. It was a cloudy day and it was a utter disaster. And in fact, when you read the account, they all had a lot to drink that evening to get over the problem. And there it’s just sat there until Bill Johnston came along.
And it turns out that they also water temperature data every time they stopped in the evening on their trip up the coast in this sweltering hot summer. What Bill Johnston has done is then looked at that water temperature data of 150 years ago taken with very accurate thermometers and compared it with the range of variability that you’ll get from one year to the other on that Great Barrier Reef now. And essentially, they found that there’s no material difference between them. If those Victorian gentlemen sailed up the coast in 2025 in the summer, would they notice any difference in temperature? Well, no, they wouldn’t, except for one major caveat. This time, they’d be in a nice air-conditioned cabin and they’d be nice and cool in that sweltering summer.
Rowan Dean:
James.
James Morrow:
But tell me, Peter, these sorts of records must be out there for other sorts of things as well when it comes to the climactic record. We’re told that, oh, well, there’s only this number of years, and they just show everything being hot. But there would be plenty of other sources of data in Australia, farm logs, things like that that go back centuries that should also be contributing to this idea that we have a data set that says, no, the world is not on fire.
Peter Ridd:
Well, I don’t know. For water temperature, it’s very tricky because nobody used to carry a thermometer. But there’s no doubt that the Bureau of Meteorology has changed a lot of the data going back into the 1800s. And that’s official data. That’s the homogenization debate as to whether they’ve done that in a justifiable way. And a lot of people, including Bill Johnston and others think it’s not done in a particularly good way. And I’ve been asking that, well, the Bureau needs to actually go back and check to see whether they’ve done that properly with proper auditors checking what they’re doing.
Rowan Dean:
Rita.
Rita Panahi:
Well, we’ve seen all sorts of data come out in the last five years showing that the Great Barrier Reef is in much better shape than we were led to believe that this catastrophic bleaching that was going to destroy this natural wonder. What’s the latest so-called scientific consensus? Have they acknowledged that perhaps they were a bit alarmist in their earlier predictions, or are they doubling down?
Peter Ridd:
The doubling down, they’re saying. Because we’ve had record amounts of coral in the last three years. We’ve never had more coral in the last three years. And they just say, “Oh, it’s the wrong type of coral.” And ironically, they’re saying it’s the weed coral, the Acroporas, the beautiful platon staple coral. And this is the crazy thing. And they forget that it’s actually those so-called weed corals that are one that are supposedly the most susceptible to hot water bleaching. We’ve ended up with record amounts of this coral that is supposedly most susceptible to climate change. It’s completely crazy.
Rita Panahi:
Wow.
Rowan Dean:
You are almost sounding a little bit like Donald Trump there, Peter, with your, “Never been so much coral. More coral than there’s ever been. Never been so much coral. It’s the best coral.” I love that.
Peter Ridd:
We would expect with a one degree increase in temperature, we should get more coral. You should have coral reefs in Sydney Harbour if it’s five degrees hotter. Because after all, corals grow right down into Victoria, but they grow too slowly because the water temperature is too high, so you would expect with a one degree temperature increase, the corals stay in the Southern Great Barrier Reef should grow 30% higher. Now, this is all well-known stuff, which is completely ignored.
Rowan Dean:
Peter Ridd, always great to chat to you. Thanks so much for coming on Outsiders from Cairns where you are, and wonderful work you do up there in Cairns on the Great Barrier Reef. Peter Ridd.
Peter Ridd:
My pleasure.
Rowan Dean:
Great to have him on the show as always. Coming up, what have we got? We’ve got lots more happening. We’ve got James’ Truth Bomb, now this is very important, in a tick.
This transcript with Dr Peter Ridd talking on Outsiders – Sky News Australia from 29 June 2025 has been edited for clarity.
