"Corals Are Thriving in Modest Warming"

 Source:

https://www.heartland.org/news-opinion/news/corals-are-thriving-in-modest-warming

"Climate alarmists have long hyped an alleged threat of purported human-caused climate change to coral reefs,

blaming every bleaching event on warming oceans and ocean acidification, and claiming the damage is permanent.

The evidence shows these claims are untrue.

The notion that climate change could cause the extinction of coral reefs is among the least-supported but most persistent assertions climate alarmists make.

Less than 20 percent of the world’s ocean area has been mapped or explored in detail.

Although coral reefs make up only 2 percent of the ocean floor,

they are often called the rain forests of the ocean because of all the seagoing species that have been discovered and described,

25 percent spend all or part of their lives on or interacting with coral reefs, depending on them for food, shelter, and protection.

The oceans are far from acidic, and they are not threatened with becoming acidic from increasing carbon dioxide emissions.

In fact, the oceans’ health is improved, not harmed, by increases in carbon dioxide.

Carbon dioxide nourishes phytoplankton, which form the foundation of the marine food chain.

The first corals arose during the Cambrian period, about 535 million years ago.

The number and types of corals increased dramatically more than 400 million years ago, when global temperatures and carbon dioxide concentrations were much higher than at present.

Corals have proved adaptable, expanding their range, evolving, and thriving through periods of higher and lower temperatures than the Earth is either currently experiencing or reasonably expected to reach in the foreseeable future.

Although adaptable, corals are limited to warm waters and aren’t found near either of the frozen poles.

Recent warming has allowed corals to expand their range modestly poleward while still thriving near the equator.

Bleaching is caused by a variety of factors, some known, some still unknown.

For most corals in most places that have suffered bleaching, human development of one sort or another, such as chemicals (including sunscreens), silt, and waste from coastal development or commercial agriculture is a prime factor.

Fortunately, many if not most of the portions of coral reefs that have suffered bleaching in recent years have already recovered.

Scientists have had no clear count of the total number of corals or coral species now in existence.

... A peer-reviewed study published recently in Nature Ecology & Evolution reveals there are more than 500 billion coral colonies in the southwestern Pacific Ocean alone.

The researchers note theirs is the first study to measure the number of corals in a large region.

Previous estimates of coral species and colonies were all based on “qualitative expert opinion”—in other words, speculative guesses—instead of observational surveys of ocean reefs.

Based on the staggeringly large and diverse number of coral and mixed coral colonies the researchers found in this one section of the Pacific, the study’s authors conclude it is extremely unlikely coral in general, or almost any coral subspecies in particular, faces extinction pressures in the foreseeable future.

Commenting on the sheer number of corals and coral species, the authors write,

    Our analysis suggests that approximately half a trillion corals (0.3 × 1012–0.8 × 1012) inhabit these coral reefs, similar to the number of trees in the Amazon.

Two-thirds of the examined species have population sizes exceeding 100 million colonies, and one-fifth of the species even have population sizes greater than 1 billion colonies.

... This means global corals would not be at risk of extinction even if there were only 10 percent as many corals as there are now.

Of course, this is just the number of corals and coral species found in a portion of the Pacific Ocean.

There has yet to be similar survey of coral reefs in the Atlantic, but there is no reason to think tens to hundreds of billions more corals won’t be discovered there if such a survey is done.

Phys.org interviewed several of the authors of the study, including lead author Andy Dietzel, Ph.D., from the ARC Centre of Excellence for Coral Reef Studies at James Cook University.

Dietzel told the journal “the eight most common coral species in the region each have a population size greater than the 7.8 billion people on Earth.”

The research contradicts the International Union for the Conservation of Nature’s (IUCN) claim that 80 coral species are facing an elevated risk of extinction.

Twelve of those species have estimated population sizes of more than one billion colonies, the researchers found.

“As an example, the finger-coral, Porites nigrescens, ranks amongst the ten most abundant species we examined.

It’s also not considered to be highly susceptible to coral bleaching—yet it is currently listed by IUCN as vulnerable to global extinction,” Prof. Sean Connolly, a coauthor of the study, told Phys.org.

Climate alarmists have made much ado about bleaching events in recent years in portions of Australia’s Great Barrier Reef.

This research shows the reef is far from being destroyed.

“We counted an average of 30 corals per square meter of reef habitat,” Connolly told Phys.org.

“This translates into tens of billions of corals on the Great Barrier Reef—even after recent losses.”

Even if the number of corals making up the Great Barrier Reef were not so varied and numerous, corals have proven resilient in the face of climate change over the eons of their existence, as I noted above.

Recent surveys show many of the coral colonies making up the Great Barrier Reef that have suffered bleaching have subsequently recovered or are in the process of doing so.

This study should put an end to the myth that corals are threatened with extinction by current or reasonably expected climate change.

The available evidence is clear: coral reefs are numerous, and modest warning does not threaten them with extinction."