Children born today may be the last generation to see coral reefs in all their glory, according to a marine biologist who coordinates its efforts to monitor the decline of the world's most colorful ecosystem.
Global warming and acidification of the oceans have already severely reduced 16-33% of all hot water reefs, but the rest are vulnerable even with a larger heater fraction, said David Obura, president of the Coral Specialist Group of the International Union for Conservation nature.
"It will be like many blinking lights," he said Observer. "It will not happen immediately, but there will be death by 1000 strokes. Between now and 2 degrees Celsius, we will see more reefs escaping from the map."
Obura added, "Children born today may be the last generation to see the coral reefs in all their glory. Today's reefs have a history of 25 million to 50 million years and have survived tectonic collisions such as Africa in Europe and India in Asia. But in five decades we have undermined the global climate so fundamentally that in the next generation we will lose the globally connected recipe system that has survived for millions of years. "
The warning follows a UN report on climate change, which has improved coral risk assessments after a faster global bleaching than expected. Intergovernmental Panel on Climate Change (IPCC) scientists have warned that if heating reaches 2C, now very likely in the next 50 years, there would be a chance of more than 99% of tropical corals being eradicated.
"Most of the evidence available suggests that coral-dominated ecosystems will be no longer at or above this temperature," said the IPCC study, which was approved by all 195 UN nations last month.
In addition to having lost one of the most beautiful and many bio-habitats on earth, the UN report has warned of the severe impact on fisheries and millions of people living in coastal communities that will lose vital income sources and will be less protected from storms.
Corals are often described as submarine forests, but they are declining much faster than the Amazon. Together with the Arctic and mountain landscapes, reefs – which have evolved over hundreds of millions of years – could be among the first ecosystems to be eradicated by the climate crisis. An increase in temperature of only 1 to 2 ° C can trigger an escape of algae on which corals depend, draining their color and making the structure fragile. These bleaching events may be temporary if the water cools, but the more frequent and the longer they last, the greater the risk of irreparable damage.
But that's exactly what happens. Whitening was first observed in 1983. It was seen globally in 1998, then in 2010, then for three consecutive years between 2015 and 2017.
"The coral bleaching events are so severe and so frequent around the planet that cold systems break into isolated pockets," said Obura. "Some of these will undoubtedly survive this century, but the highest scientific evidence tells us that if we do not do everything to limit heating to 1.5 degrees Celsius, we will lose 99% of coral reefs in the world in the coming decades ".
Eleven of the 29 World Heritage reefs have already been bleached. As far as current trends are concerned, UNESCO estimates that it will increase to 25 by 2040.
On a broader scale, the reefs in Saudi Arabia, Madagascar, Hawaii and Papua New Guinea are the most vulnerable, which are likely to undergo a bleaching before the global average of 2043. Those with a longer survival expectation large – yet thin – Egypt, Australia (including the Great Barrier Reef), Cuba, Indonesia and the Philippines.
But there are other threats that go beyond heating and acidity. Outside the Philippine island of Palawan, dusty reefs have been severely affected by sewage drainage from tourist resorts, pollution from boats and reckless fishing, including pumping cyanide into the coral structure to stun the floating fish and pull up and sell off for home aquariums in China.
According to Vince Cinches, the Southeast Asian Oceans Campaign of Greenpeace, it is a calamity that this is happening in the Coral Triangle, which should be a haven because it is one of the oceanic regions most resistant to climate change. "Even in the Philippines, we quickly lose coral, "he said. "We need to reduce the stress of overfishing, coastal development, pollution, mining, tourism and climate change."
Although some conservatives risk their lives to prevent this, economic pressures continue to grow and chances for survival of coral are weak. The IPCC report noted that even if the temperatures were kept at 1.5 ° C, between 70 and 90% of the reefs would be lost.
Some of the more than 800 species of corals have already been declared missing, but as long as the main cold builders have continued to exist, there is a weak possibility that these complex systems can be rebuilt if the temperatures are to stabilize.
Scientists like the Weapon are moving more and more to support rather than observation, but they say the last great function of corals is to teach people to better care for other ecosystems.
"I'm a generation of scientists who want to disappear. It's very depressing," he said. "Over 1.5 degrees Celsius, about 50 years old, will be legendary ecosystems with beautiful virtual amusements and a treasure of fantastic historical movies and images, but little to be seen in real life."
"We are trying to do more than to record the decline by making activist statements." We must convey the message that we must stop this from other ecosystems, which motivates us. impact. "