A recent article in The Hill, “Climate change is not a ‘con job’,” claims that catastrophic, human-caused climate change is killing reefs via ocean heatwaves. This claim is false. [emphasis, links added]
In reality, corals have existed for millions of years, through warmer and colder periods, and in the recent past, coral reefs have recovered from bleaching events and even die-offs, proving the species is adaptive and resilient in the face of climate change.
The Hill article, from Rebecca Vega Thurber, the director of the UC Santa Barbara Marine Science Institute, is framed by Thurber’s annoyance that President Donald Trump says climate change is a “con job.” She claims her personal research experience refutes his comment.
Thurber explains that pollution from fertilizer runoff can kill corals, which is true, but goes on to assert:
“[E]very result we have collected, in every one of these well-intentioned and carefully designed experiments, was waylaid by the increasingly frequent and severe heat waves that have arisen in the last decades.”
She says their efforts to mitigate pollution were “overwhelmed by high water temperatures driven by climate change, or worse, climate change killed our whole experiment.”
Thurber claims marine heat waves in the French South Pacific hampered her work by “transform[ing] these normally bountiful reefs from habitats where there was once 60 percent of the seafloor covered with healthy corals to barren plains with less than 1 percent live coral.”
In point of fact, one long-term study from 2019 showed that rather than a “barren plain,” French Polynesian reefs have an “outstanding rate of coral recovery, with a systematic return to pre-disturbance state within only 5 to 10 years.”
A second study from 2024, published in Nature, sought to understand why reefs bounced back so readily after major heat waves, concluding that:
“Over the past three decades, there have been five main warming events that have caused mass bleaching around Moorea and Tahiti, in 1994, 2002, 2007, 2016, and 2019. Despite bleaching levels up to 100% for some coral species, reefs experienced as high as ~76% recovery following each event. …
“It is currently unknown what controls the ability of coral coverage to recover quickly at these locations. It has been suggested that reefs may develop an increased tolerance to higher SSTs following each bleaching event, and that the increased resilience would allow for a shorter recovery period with less die-off under subsequent SST extremes.”
In short, the scientific literature does not support Thurber’s contention in The Hill that coral reefs are dying off in vast numbers.
Interestingly, [in 2019], The Hill published an article with a different tone, discussing the fact that coral reefs were thriving “despite warming seas,” but the outlet seems to have forgotten this.
What Thurber and The Hill also neglected to mention was that recent mass die-offs did not just coincide with heat waves alone.
Rather, a spate of tropical cyclones and crown-of-thorns starfish outbreaks occurred over the same period, resulting in multiple coral colony declines. Multiple stressors are harder on a species than any of those dangers would be alone.
Thurber mentions that Australian reefs are another part of her area of research, but she does not mention that 2024 was the third year in a row where the Great Barrier Reef had record-breaking coral coverage.
Unfortunately, close study of reef die-offs barely existed in the early parts of the 20th century and before, so short-term records like single-event tied die-offs do not stretch into the preindustrial period for comparison.
As a result, it is all too easy for alarmists to assert, for example, that marine heat waves are unprecedented when there are only a few decades of satellite data to work from.
Longer-term studies, and a knowledge of how coral reefs around the world are built over time, show that coral death is part of the reef construction process.
Coral reefs have survived much hotter periods than today, like the Paleocene-Eocene Thermal Maximum, which was 5-8°C hotter, as well as much colder glacial periods. One reason for this is that coral organisms are not immobile.
Even if particular regions became too hot, which is highly unlikely in our lifetimes, corals could just migrate poleward, as research suggests they did in the past. Change like that might be uncomfortable for narrowly-focused researchers, but it is part of the Earth’s history.
The Hill did a disservice to its readers by publishing this article, which served no other purpose than to frighten readers into ignoring Trump’s important point: bad actors (particularly at the United Nations, where he made the comments) are using climate alarm to promote harmful leftist-favoring policies to enrich themselves.
I am sure that Thurber is a “true believer” in the catastrophic warming narrative, but it does not help her case when essential facts are left out of the argument and when the multiple sources of data that do exist contradict her claims.
Read more at Climate Realism
April, 1970. My wife and I did the ‘glass bottom’ boat tour at Green Island off the coast at Cairns. A 35mm film camera. About half the photos showed ‘dead’ – due to crown-of-thorns starfish. One tiny dot in a reef that’s 1,500 miles long.
I just looked up what those crown-of-thorns starfish are. They look to be quite nasty and can devastate a colony quite quickly. But those who claim that human-caused warming causes the die-outs won’t look for any other explanation. And as the author here points out the length of time where we even have data on ocean “heat waves” is too short to make claims as to how these colonies die off.
The planet is actually cooling and has been since 2006. There is a tectonic hot spot near Indonesia that builds up heat in the ocean, which then heads west. Most of coral bleaching is the coral changing to symbiotic algae more suitable for colder or warmer conditions. Many observers observe bleaching but do not go back six months later and observe the great recovery. The rainforests and corals are the two most resilient ecosystems, evidenced by their complex ecosystems which took millions of years to evolve. Just because they are complex, unthinking ecologists assume they are delicate. It is the exact opposite.