Natural Cyclical Events Impact More Than Human Activity

Recently, I spoke in the Senate regarding the impact of this summer’s flooding on the coral reef. Coral polyps are saltwater creatures. When floodwaters impact the reef, it introduces fresh water, cold temperatures and sediment, all of which cause coral bleaching. El Niño (ENSO cycles) causes a reduction in clouds, resulting in higher solar radiation, higher temperatures, and coral bleaching.

Both of these are cyclical and not caused by human activity. Yet the Great Barrier Reef Marine Park Authority (GBRMPA) appear to be focusing solely on the “climate change is causing warming temperatures and coral bleaching” argument instead of presenting the broader picture.

I was reassured that the GBRMPA accepts that ENSO cycles play a role in coral bleaching. I look forward to more honesty and transparency on this issue from the BOM, CSIRO and the globalist controlled Australian Institute of Marine Science.

Transcript

Senator ROBERTS: Thank you for appearing tonight. Let me start with a simple question: can floodwaters entering the reef from the 28 river systems that discharge onto the reef in a rain event, such as a tropical cyclone, cause coral bleaching, either through fresh water itself, through very low floodwater temperature, or through high nutrient levels or turbidity or sediment?

Mr Thomas: There can certainly be initial freshwater bleaching from flood events.

Mr Quincey: And we did see some of that this year with the cyclones in the north.

Senator ROBERTS: It’s true that corals also bleach from water that is too cold, isn’t it? I can remember that in June 2008 that there were record cold temperatures in various parts of Queensland and the Northern Territory, including southern Queensland, and the southern Great Barrier Reef bleached because of the cold weather.

Mr Thomas: I’m not sure of that particular example. But, yes, bleaching is certainly a stress response that can be triggered by a range of different things. Most recently, though, our biggest concerns have been about warmer waters, not colder waters.

Senator ROBERTS: Was any of the coral bleaching that was evident on the reef in the first quarter of 2024 caused by freshwater and salt intrusion?

Mr Thomas: Yes, as Mr Quincey said. Probably because of flood events prior to and post Christmas in in the north, there would have been some initial freshwater bleaching. I don’t have specific details of that in front of me, though.

Senator ROBERTS: Thank you. Was any of the coral bleaching in the first quarter caused by pesticides or other chemical run-off from farming areas?

Mr Thomas: Direct attribution of those impacts would be difficult for me to provide here today, but we could take some of that question on notice.

Senator ROBERTS: Please. According to a paper from the University of Queensland, simplified: The most devastating mass coral bleaching has occurred during El Niño events … However, El Niño itself does not cause SSTs— sea surface temperatures— to rise in all regions that experience bleaching. Nor is the upper ocean warming trend of 0.11°C per decade since 1971 … sufficient alone to exceed the thermal tolerance of corals. This paper shows that a major contributing factor is El Nino reducing cloud cover, causing ‘higher than average air temperatures and higher than average atmospheric pressures’ and playing ‘a crucial role in determining the extent and location of coral bleaching’ on the reef. Is that a fair statement?

Mr Thomas: I’m not aware of that particular paper. Did you say it was the University of Queensland?

Senator ROBERTS: Yes.

Mr Thomas: I’m not aware of it. I’m sorry. But we would be very interested to read more about it.

Senator ROBERTS: We can get it to you.

Mr Thomas: Yes, please.

Senator ROBERTS: Do you accept natural, cyclical ENSO events play a crucial role in coral bleaching?

Mr Thomas: We would have to defer to climate scientists around the particular localised impacts and how they’ve played out on the Great Barrier Reef.

Senator ROBERTS: Localised impacts, not global?

Mr Thomas: For how those significant meteorological phenomena impact the Great Barrier Reef in particular, I would need to consult with other relevant experts.

Senator ROBERTS: According to the Bureau of Meteorology document ‘124 years of Australian rainfall’, there’s no trend. There’s no pattern. It’s just cyclical. There’s no trend whatsoever, down or up. It’s just natural variation, influenced by cycles. In the last five years, we’ve had three La Ninas. Your website, under the heading ‘What causes coral bleaching?’, makes the comment: The biggest cause of coral bleaching in the past 20 years has been rising water temperatures. On notice if you wish, please provide how much water temperature has increased in the last 20 years, including average and range, showing any spikes that may have occurred.

Mr Thomas: Thank you. We will take that on notice.

Senator ROBERTS: Something like that, maybe?

Mr Thomas: I’m not sure I can reproduce that exactly, but we’ll certainly take that—

Senator ROBERTS: No, I wouldn’t expect you to reproduce it.

Mr Thomas: We will certainly try to take an—

Senator ROBERTS: Thank you. Have you tested those spike temperatures that may have led to bleaching against the ENSO cycle? Have you correlated them?

Mr Quincey: I couldn’t answer now, but we would most likely consult with our colleagues not only in the Bureau of Meteorology but in the CSIRO and the Australian Institute of Marine Science, who do some of that work.

Mr Thomas: We’re not the authors of some of these reports. We work with those relevant institutions. We pull that information together. We try to synthesise it and make the best assessments we can on how we can hone our programs and better manage the Great Barrier Reef into the future. With some of the specificity and science you’re referring to, we really would need to speak to some of our experts.

Senator ROBERTS: Okay. This is the last question. The bleaching impact statement on your website, which you describe as ‘a framework to describe and categorise coral bleaching on the Great Barrier Reef’, only includes one factor: heat stress, which you attribute to climate change, ignoring these other crucially important factors. Is this about blaming bleaching on climate change, which is well-funded, and ignoring the role of natural cycles, which carries no funding? We’ve heard the United Nations say that the planet is now boiling.

Mr Thomas: Is your question about whether our framework for understanding coral bleaching is limited to heat stress?

Senator ROBERTS: Yes, it seems that it’s only limited to heat stress.

Mr Quincey: It has it there as heat stress, but the exposure blocks the subtleties of exactly what you’re talking about—about light intensity and exposure and cloud cover. Also, on our website, we really try to convey that local and regional weather in particular places has a large bearing on the outcomes that we see each summer, and those factors play into that.

Senator ROBERTS: Thank you.