Newly released data about Australia's Great Barrier Reef is being distorted by some as evidence coral is thriving under waters warmed by human emissions. But scientists caution cover is only one measure of the health of the complex ocean structures and said monsoon activity that cooled the region's waters at the height of the season in 2026 is too unpredictable to be relied upon.
"Yet another disaster for climate scammers," says an August 11 X post by podcaster Tom Nelson -- the producer of misinformation-riddled climate film (archived here).
Nelson's post includes a graphic purportedly showing "record high" coral cover in Australia's Great Barrier Reef in 2026.
"Last 5 years, Great Barrier Reef coral cover better than ever. But many deeply worried people don't want to hear," adds Bjorn Lomborg, a long-time climate contrarian, in an August 15 post, also on X (archived here).
The posts draw from a real report published by the Australian Institute of Marine Science (AIMS) on August 11 (archived here).
In it, AIMS states that hard coral cover across all three regions of the reef "increased slightly or remained similar to levels recorded in 2025."
It said this signaled the start of a recovery from record bleaching events that struck the region in 2024, fueled by warmer waters due to human emissions (archived here).
But coral cover trends in 2026 "do not nullify the longer-term, emerging trend of volatility on the Reef," an AIMS spokesperson told AFP in an August 20 email.
The "Reef remains under pressure from climate change."
Independent experts agreed that the report did not prove long-term resilience or recovery.
Sara Cannon, postdoctoral fellow at the Institute for Oceans and Fisheries at the University of British Columbia (UBC) in Canada (archived here), told AFP: "The recovery is genuinely encouraging, and it shows the reef retains real capacity to regrow when conditions allow. But resilience is a ratio: recovery rate against disturbance frequency and severity."
Marine scientists highlight the increased fragility of the Great Barrier Reef over recent decades (archived here).
One factor is monsoons -- a shift in winds that often causes a very rainy season or a very dry season (archived here). They have been studied as a natural relief to bleaching events across the globe (archived here, here and here).
At the end of the 2025-26 summer, the AIMS report said the reef benefited from monsoon activity which brought increased cloud cover and rainfall that reduced sea surface temperatures and likely limited bleaching events at a critical point in the season (archived here).
"The reef caught a break from the weather," said Cannon in an August 20 email. "That is a favorable roll of the dice, not evidence of increased biological resilience."
Ove Hoegh-Guldberg, emeritus professor at the University of Queensland, concurred (archived here).
"We cannot rely on tropical cyclones and monsoons as an insurance policy for the Great Barrier Reef," he told AFP in an August 21 email.
Additionally, storms can cause direct damage to coral, themselves, as well as localized flooding that can kill certain species (archived here).
Scientists also said the health of a reef cannot be grasped from the percentage of hard coral cover alone.
The metric does not account for its biodiversity, composition, the size and age structures of its colonies, as well as its density or disease load.
"Reading reef health from cover alone is a bit like assessing a forest from canopy cover in a satellite image: useful, but it will not distinguish old growth from a young monoculture that regrew after a fire," UBC's Cannon said.
Experts have repeatedly told AFP that acropora coral species drive rapid structure rebounds (archived here).
"They are first to grow and first to go, and the 2024-25 results illustrated exactly that," Cannon remarked, highlighting acropora corals' high mortality rates during the mass bleaching events experienced during those years.
Kate Quigley, a senior research fellow at James Cook University in Australia, also said cover is not the only measure of a reef's ability to maintain high levels of biodiversity (archived here).
A "reef can have high coral cover but still be fundamentally different from past states and may not provide the same suite of functions that the reef previously performed," she told AFP in an August 19, 2026 email.
Fast growing coral are also the most vulnerable to heat stress, cyclone damage and harm from crown-of-thorns, a large, venomous starfish native to Indo-Pacific that feeds on corals (archived here).
Crown-of-thorns populations are on the rise in certain regions of the Great Barrier Reef, according to AIMS data.
Several scientists AFP spoke to highlighted the "high volatility" of the Great Barrier Reef's cover as a serious concern.
It "should be interpreted as the response of a large and resilient system to severe stress from repeated extreme events," said University of Melbourne senior lecturer Benjamin Henley in an August 19 email (archived here).
Previous research across the Great Barrier Reef shows marine heatwaves can simplify reefs by reducing diversity and altering community structure outright (archived here).
AFP has extensively covered misinformation surrounding ocean acidification and coral bleaching events, including at Australia's Great Barrier Reef.