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.