Coral reefs will completely disappear in 30-40 years
Last reviewed: 16.10.2021
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Australian professor Peter Seil from the United Nations Institute for Water, Environment and Health published the book "Our Dying Planet", in which he predicted a very unattractive future for us and our descendants.
In addition to the usual things - climate change is not for the better, ocean oxidation, impoverishment of fish stocks, environmental pollution and the spread of "dead zones" in the coastal waters - the author believes that until the end of the century (perhaps, in 30-40 years) the coral reefs will disappear completely. This will be the first ecosystem destroyed by man, emphasizes the scientist. Already people were born who will live in a world devoid of corals.
"We create a situation where the organisms that build coral reefs either disappear or will be extremely rare," the specialist writes. "Because of this, they can not build a structure, which we call a reef." And we are working on their destruction for many years. "
Coral reefs are an important link in biodiversity. They are home to every fourth marine species, although they occupy only 0.1% of the area of the World Ocean. By the number of species per unit area, they are even more diverse than tropical forests.
Recent studies have also shown that in case of death of corals, medicine will lose many useful substances. For example, a few months ago, a new method of treating leukemia based on a sponge inhabiting reefs was announced. Corals also found compounds that can serve as a powerful sunscreen.
And economic value! First - the fish. Secondly, tourism. About 850 million people live within 100 km of reefs, and for about 275 million of them reefs are a source of subsistence and livelihood. In addition, reefs protect low-lying islands and coastal areas from extreme weather conditions, absorbing waves.
Carbon emissions from human activities are the main cause of the expected decline. First, the greenhouse effect increases the temperature of the ocean surface (in the last century it increased by 0.67 ˚C). Because of this, photosynthetic algae are disappearing, providing corals with energy, and they become discolored, and then die within a few weeks.
Secondly, water oxidizes. About a third of the carbon dioxide that we put in the atmosphere is absorbed by the ocean surface. As it turned out relatively recently, as a result of this process, reef organisms find it more difficult to extract the compounds necessary for the creation of carbon skeletons from water.
However, Mr. Sayle forgets to make an important reservation about the amazing vitality of corals (if we believe our data on previous episodes of mass extinction of species). "There have been periods of existence and absence of reefs, despite the fact that the reef creatures have been living for hundreds of millions of years," says Mark Spalding of Cambridge University (Great Britain). "If climatic conditions permit, they build their fantastic structures, and if not, await as their unremarkable invertebrates."
It should be noted that the disappearance of reefs usually preceded mass extinctions. The author ominously calls them an ecological analogue of a canary in a coal mine. About 20% of coral reefs have died in recent decades. Mass discoloration is a relatively new phenomenon: scientists have been observing corals since the 1950s, but this was only noticed in 1983. "In 1998, I witnessed how literally 80-90% of Seychelles coral reefs perished in a matter of weeks," Mr. Spalding recalls with horror. Only this episode led to the disappearance of 16% of the coral of the planet.
Mr. Sale says that the subsequent cases of mass extinction of corals in 2005 and 2010 were not so impressive just because there were almost no corals left.
These dramatic episodes coincide with unusual weather conditions (for example, El Niño), that is, they may be the result of natural causes, but because of climate change now happen more often and lead to more serious consequences. In short, the fight against global warming is an urgent matter. Under no circumstances should the atmospheric concentration of carbon dioxide exceed 450 ppm. Today, this figure is about 390 parts per million, and many experts believe that the "500" mark will be overcome quite soon.
Efforts at the local level can also be useful. Alex Rogers of Oxford University (UK) says: "We know for sure that if you stop overfishing and water pollution, the corals will have a much better chance of recovery. But that we will not save them - we will only gain a little time if climate change continues at the current rate. "
Although not all scientists agree with the timeframe outlined in the book, the crisis is obvious. "When it comes to destroying an ecosystem during the life of one human generation, it's just a figure of speech," Mr. Rogers said. "But the idea is correct: people do not understand how fast the changes are happening now."
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