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New research shows that warming temperatures in the Indian Ocean could lead to the return of an ancient El Niño- style system not seen since the Ice Age that may increase storms, floods and droughts that occur around the Indian Ocean, impacting vulnerable regions already threatened by the climate crisis.

The study, published in Science Advances, shows that small surface temperature increases in the Indian Ocean could see its associated weather patterns start to match the El Niño patterns currently seen over the Pacific Ocean, as soon as 2050. This matches up with how winds and rainfall used to affect the region during the last ice age, at least 21 000 years ago. This threatens some of the people that are already at extreme risk from the climate crisis, across Africa, Asia and Australia. 

Pedro DiNezio, one of the lead authors of the study, says, “Our research shows that raising or lowering the average global temperature just a few degrees triggers the Indian Ocean to operate exactly the same as the other tropical oceans, with less uniform surface temperatures across the equator, more variable climate, and with its own El Niño.”

You might also like: Reducing Carbon Emissions Will Benefit the Global Economy- Here’s How

The Indian Ocean Dipole and the Australia Fires

El Niño is a weather system characterised by unusually warm water in the Pacific Ocean off the coast of Peru and Ecuador. It is linked to droughts in Australia and heavy rains in South America and is exacerbated by the climate crisis.

The researchers analysed 36 different climate models, picking out the ones that matched current weather conditions most accurately. These models were then used to examine how further warming might change the meteorological conditions around the Indian Ocean.

Currently, the Indian Ocean sees little change in temperature year-on-year; the west-to-east winds tend to keep conditions stable. However, the models show that the climate crisis may reverse these winds, completely altering weather patterns in the region. The study shows that the rising temperatures of today are affecting the Indian Ocean in a similar way as the glaciers did tens of thousands of years ago.

This could lead to increased flooding in some areas to longer dry spells in others, affecting massive parts of the world already feeling the effects of the crisis, as seen recently with the bushfires in Australia. 

These studies are valuable in showing the future impacts of human activity on the planet, and allow countries to plan to a certain extent, however in many countries, there simply are not enough resources to plan for the climate crisis in a meaningful way. 

DiNezio says, “We are certain that the risks of these extreme events are becoming larger and larger as we pump more CO2 into the atmosphere, and certainly going to have an unequal impact on countries in the tropics.”

Featured image by: Jon Sullivan

A new study states that it is not too late to save our planet’s coral reefs before they go extinct.

Coral Reef Extinction Facts

Coral reefs host a quarter of the Earth’s marine biodiversity and support livelihoods of more than half a billion people. But, the planet has already lost half of its coral reefs over the last three decades, and more than 90% of them might become extinct by 2050.

Corals face a number of threats including overfishing, diseases, and pollution, while the biggest of them all is climate change. The world’s largest coral reef system- the Great Barrier Reef, which is visible even from outer space- has lost half of its coral in the past two years because of extreme heat stress from global warming.

While conservationists around the globe are grappling with how to preserve the last surviving ‘underwater rainforests’, the most comprehensive study on coral reefs published last week has suggested a few ways to save them. As part of the research, an international group of 80 scientists surveyed more than 2,500 coral reef systems across 44 countries to determine how to protect them in the face of extensive damages caused by human activities and global warming.

“The good news is that functioning coral reefs still exist, and our study shows that it is not too late to save them,” said Emily Darling, the lead author of the study and a Wildlife Conservation Society (WCS) scientist leading the global coral reef monitoring program. “Safeguarding coral reefs into the future means protecting the world’s last functioning reefs and recovering reefs impacted by climate change. But realistically — on severely degraded reefs — coastal societies will need to find new livelihoods for the future.”

Examining coral abundance in the Indian and Pacific oceans, they found that many of the reef systems were full of complex species that created distinctive structures and were functioning in spite of deadly marine heatwaves in recent years.

Heatwaves had affected many coral reefs during the El Niño event between 2014 and 2017. But 450 reefs in 22 countries survived in protective cool spots. The scientists believe those areas should be the focus of urgent protection and management efforts. Previously, the Indo-Pacific reefs were also hit by mass coral bleaching and heat stress in 1983, 1998, 2005 and 2010, before the world’s most intense, longest and largest bleaching event between 2014 and 2017.

You might also like: Artificial Corals: Improving the Resilience of Coral Reefs (part II)

A marine scientist gathering data on coral reefs in the waters of Fiji. Credit: WCS

How to save coral reefs?

The researchers outlined three conservation strategies to save the reefs: protect, recover, and transform. As part of the first strategy, the international network of coral reef conservation should focus on protecting functioning coral reefs found in East Africa to Southeast Asia, the Coral Triangle, and the Pacific. The second strategy is to promote rapid recovery of coral reefs impacted by the 2014-2017 coral bleaching event. To implement the third strategy, selected coastal communities around the world should be relocated to avoid dependence on reefs that are no longer functioning.

The scientists pointed out that strategic local management can help protect corals through tools such as marine protected areas, or other management restrictions that reduce threats and keep coral reefs above functional thresholds.

“While coral reef sustainability depends largely on reducing carbon emissions, identifying reefs that are likely to respond — or importantly, not respond — to local management is critical to targeting development and management strategies to build the well-being of the millions of people dependent on coral reefs across the globe,” said Georgina Gurney, study co-author from the ARC Centre of Excellence for Coral Reef Studies at James Cook University

The researchers also noted that limiting global temperature within two degrees Celsius over pre-industrial levels is the only way to ensure the survival of reefs.

“Saving reefs will require combining local and global efforts, such as reducing local dependence on reef fish to maintain a reef’s important functions while also reducing carbon emissions to keep warming below 1.5C,” said Tim McClanahan, co-author of the study and Wildlife Conservation Society senior conservation zoologist.

Gabby Ahmadia, director of marine conservation science at World Wildlife Fund and co-author of the study said that the study would help policymakers and conservationists make informed management decisions for coral reefs and the communities that rely on them before they go extinct.

 

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