Science Rebuts New Claims that Warming Is Destroying Coral Reefs

The Associated Press and many other corporate news outlets are promoting a new report by an environmental activist group claiming climate change is threatening the Great Barrier Reef and other reef systems with irreversible bleaching and death. To the contrary, scientific data show coral reefs are expanding their ranges in response to warming oceans. Also, the majority of Great Barrier Reef corals that have bleached have subsequently recovered, showing coral communities’ resilience to manmade and natural perturbances.

A new paper by the International Union for the Conservation of Nature (IUCN) makes the alarmist reef claims promoted by The Guardian, the Associated Press, the Albuquerque Journal, and others. The Guardian’s article, titled “Great Barrier Reef outlook ‘critical’ as climate change called number one threat to world heritage,” is typical of the media’s fawning and uncritical coverage of the IUCN report.

“The conservation outlook for the Great Barrier Reef has worsened from ‘significant concern’ to ‘critical’ – the most urgent status under the IUCN system,” asserts the Guardian. “The reef suffered its third mass coral bleaching in five years during the 2019-20 summer.”

The Guardian implies that the entirety of the GBR as bleached during these events, but this is not true. As pointed out in Climate at a Glance: Coral Reefs, the Australian Institute of Marine Science documented that only about 22 percent of the reef experienced recent bleaching, with evidence showing much of the Great Barrier Reef has recovered from the bleaching events.

Scientists intimately involved with Great Barrier Reef research commented on the IUCN paper, pointing out climate change was only one possible factor contributing to GBR’s bleaching, with the others being, inappropriate commercial fishing, terrestrial run-off from farms, and urban development along the coast. The latter two activities, in particular, have caused a decline in water quality that has harmed the reef system.

What’s true of the Great Barrier Reef is true of other coral reefs around the world, despite activist claims that climate-induced bleaching events are ringing a death knell for corals around the world. The media prominently reported those claims, only to have all or large portions of the affected reefs recover in subsequent years.

Coral require warm water, not cold water, to thrive and survive. They are unable to live and colonize outside of tropical or subtropical waters. As a result, as the Earth has modestly warmed, coral are extending their range toward the poles while still thriving at and near the equator.

Coral have existed continuously for the past 40 million years, adapting to often abrupt and significant temperature shifts repeatedly. Historically, coral have thrived during periods when ocean temperatures were significantly warmer than they are today.

Moreover, studies show coral can and do adapt to the gradual long-term pace of global warming.

Scientists report that the primary reasons for bleaching events include sediment pollution from nearby coastal lands, chemicals found in sunscreen, and cold temperature events.

Contrary to the fawning media coverage of a paper published by an unabashed activist group, the scientific evidence indicates factors other than warming oceans are the true threat to coral reefs. Thankfully, research also demonstrates coral often recover from and adapt to the bleaching events that do occur.

H. Sterling Burnett
H. Sterling Burnett
H. Sterling Burnett, Ph.D., is the Director of the Arthur B. Robinson Center on Climate and Environmental Policy and the managing editor of Environment & Climate News. In addition to directing The Heartland Institute's Arthur B. Robinson Center on Climate and Environmental Policy, Burett puts Environment & Climate News together, is the editor of Heartland's Climate Change Weekly email, and the host of the Environment & Climate News Podcast.

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