The near vertiginous rise in the growth of coral over the last five years across Australia’s Great Barrier Reef should put the tin hat on the ubiquitous Armageddon predictions of the imminent collapse of the reef – at least for the time being. According to the latest survey by the Australian Institute of Marine Science (AMS), coral cover rose by 27% in the northern reef. Massive growth of 26% and 39% were recorded in the central and southern areas respectively.
As late as October 2020, the BBC was telling stories about the Reef losing half its coral and citing a study that said it was due to “warmer seas driven by climate change”. No doubt the recent heartening news of recovery will delight Extinction Rebellion supporter and Guardian activist George Monbiot. He was one of the first to start the coral doomsday ball rolling by telling his readers in 1999 that the “imminent total destruction of the world’s coral reefs is not a scare story”. Forecasting that most of the coral in the Indian Ocean will die by 2000, he suggested that one of the world’s great ecosystems “is now on the point of total collapse”.
Tropical coral thrives in waters between 24°C and 32°C. It is highly adaptable but seems to dislike sudden changes in temperature, often caused by natural weather oscillations such as El Niño events. Under such conditions it can die back and bleach, but as recent evidence shows, it quickly recovers when normal localised conditions return. Global warming started to run out of steam a couple of decades ago and there has been a standstill for at least seven years. However, minor long term temperature changes are unlikely to cause many problems for highly resilient coral. The resilience is clearly shown below in the latest AMS figures for the northern Reef.
The recovery was just as dramatic in the central part of the reef.
AMS data for the northern and central Reef, where water temperature is higher, show that there were very rapid increases in the coral cover. This was helped by few ‘disturbances’, of which the most significant was a recent absence of crown-of-thorns starfish attacks. It is also noted that most of the recent increase is due to the fast-growing Acropora coral – which of course accounts for a lot of the routine die backs when conditions turn less benign. All of this looks like natural processes, although the AMS is still wedded to the notion that human-caused climate change is a major culprit. The Reef remains exposed to “the predicted consequences of climate change”. The observed recovery “can be reversed in a short amount of time”, it says.
Significant research into the Reef only got going in the mid 1970s. Before that, the area was largely unobserved and few records about bleaching and temperature changes were made. Last Monday, the Daily Sceptic reported that a treasure trove of 1871 sea temperatures taken on board a scientific mission travelling the length of the Great Barrier Reef had recently been compared to current measurements logged at the same areas. No differences were found by research scientist Dr. Bill Johnson, leading him to conclude that: “Alarming claims that the East Australian Current have warmed due to global warming are therefore without foundation”.
The dataset has been know about for a few months but largely ignored, presumably because the findings disturb the current political agenda. A common dismissive trope was that the measurements were likely to be inaccurate. However, it seems unlikely that a group of scientists in 1871, on a scientific mission travelling to view a total solar eclipse off Cape York, were unable to correctly use a thermometer. The readings may have flaws and be open to other interpretations, but they undoubtedly offer an interesting insight into the history of the Reef. Certainly, such rare data should not be dismissed out of hand.
The lack of vintage temperature data is a big problem in the climate world. The main surface temperature database used by the IPCC and scientists around the world is HadCRUT, run by the U.K. Met Office Hadley Centre and the Climate Research Unit at the University of East Anglia. A recent PhD student John McLean found that the database was started in 1850, but after five years just three stations were reporting data from the whole of the southern hemisphere. It wasn’t until 1950 that 50% of the area was covered.
Meanwhile, it will be interesting to see if the Reef’s dramatic recent recovery affects the huge funds and grants that have poured into the area over the last 25 years. Biologist and long time observer of Reef politics, Jennifer Marohasy has documented the growth of the finance involved since 1998. This was when the World Wildlife Fund launched its campaign focused on the Reef, and saw its Federal Government grant increase seven-fold over four years to A$3.5 million. She notes that Reef temperatures are now monitored by the AMS at 80 sites, “and do not show a long term warming trend”. Furthermore, says Marohasy, there are no studies showing either a deterioration in coral cover or water quality. But still the headlines suggest a problem, she reports.
In January this year, the Australian Government announced A$1 billion to save the Reef. In Marohasy’s view, “This is really protection money to be paid to the Reef Mafia; not really to protect the Reef”. There will be a rush to get the money, she continued, “and then it will be taken out into the pockets of the many who will continue the myth of the dying Great Barrier Reef”.