A Closer Look at the Recent Mass Coral Bleaching Events

Naila Moloo
6 min readMar 22, 2022


Climate change is the largest threat that humanity is facing today, impacting our society, biodiversity, and economy. Climate describes the long-term (30+ years) and average weather conditions in a specific region and is regulated by a natural phenomenon called the greenhouse effect. Greenhouse gases, like carbon dioxide and methane, trap radiation in the Earth’s atmosphere and are responsible for keeping the planet warm enough to support a range of biodiversity.

However, human activities such as burning fossil fuels release greenhouse gases into the atmosphere which enhances this greenhouse effect and has been causing the Earth to rise in temperature at an alarming rate of around 0.17°F per decade since 1901. In fact, 2019 and 2020 were both ranked among the top three warmest on record.

The Warming Ocean

We often focus on the effect that climate change has on land (which makes sense, because that’s where we live) but the effects are actually far more acute in the ocean.

Burning so many fossil fuels causes a major increase in the presence of greenhouse gases, and because of this, the ocean is warming rapidly. 90% of the heat in the atmosphere gets absorbed by oceans, and when the ocean warms by such a large degree, everything living there is impacted. One species that has taken a severe hit are coral reefs.

Coral Bleaching

Corals are made of small plankton-eating animals called polyps, so they are live animals. Coral bleaching occurs when there is a major change in environmental conditions mainly with regards to heat. When there are various stressors, the flesh of coral reefs begins to rot and expel the symbiotic algae that live in their tissues and then the corals turn completely white. For reference, here is an image showing the change from a colourful and alive coral to a “bleached” coral.

Not only do coral reefs bring vibrancy and beautiful pigments to the ocean, but they play crucial roles for the environment and economy alike.

Over half a billion people are dependent on coral reefs for food, income, and protection. They protect coastlines, provide habitats for ecosystems, and are key for fields like the fishing industry. On top of this, they provide billions of dollars in income through tourism and recreation, and actively combat climate change; coral reefs are huge carbon sinks because of the tiny photosynthetic cells they contain, so they literally clean the air! This is why it is so detrimental that coral reefs all over the world are turning white.

The Great Barrier Reef

The Great Barrier Reef, located off the coast of Queensland, Australia, has lately been attracting a lot of attention because of how quickly it’s dying, which can be credited to the stress from increased water temperatures and UV radiation. The reason this is so problematic is that, stretching over an area of 133,000 square miles and made up of 3,000 individual reefs, it is the largest coral reef in the world.

Because it is so vast, it also holds vast significance. The reef contributes around 6 billion dollars to the Australian economy and supports over 60,000 jobs, and now there is a sixth mass bleaching event unfolding on the reef, adding to prior events. The Great Barrier has suffered from coral bleaching caused by very warm ocean temperatures over the years; between 2016 and 2017, 50% of corals at the Great Barrier Reef were killed by two ocean heat waves.

What's also scary is this is happening during a La Niña weather event, which normally means rain and cloud cover, translating to cool waters. However, we still see these bleaching events happening and it just shows what global heating is doing to the reef.

Should the Great Barrier Reef be Considered Endangered?

There is absolutely no doubt that coral reefs are under severe threat, and now the United Nations is considering classifying the Great Barrier Reef as endangered. Last year, The World Heritage Committee withdrew from including it on its list of “endangered” sites which came as a shock to many, but now that it’s only gotten worse, UNESCO is currently assessing whether the Australian government has done enough to address threats to the barrier before the World Heritage Committee considers including it on the list of endangered sites in June 2022.

Why has this taken so long to do, though? Why has it taken 1/2 of the Great Barrier Reef being lost, and 98% of the reef affected? The reason falls under the benefit of humans (which isn’t surprising). Because the reef remains such a vital tourist draw for Australia, an “in danger” label could deter visitors and reduce the money it brings in. Now that this is finally being exposed, the reef’s resilience has already been notably compromised.

Can We Save Coral Reefs?

The final question we arrive at, then, is can we save coral reefs like the Great Barrier? If we take immediate action, it’s possible. For me, there are a few things that come to mind.

The number one action item is that governments need to set even more ambitious targets. If we want the reef to survive, the only response can be urgent action and we need to work to a net 0 emissions economy. The government must create policies that will drive systemic change. Why are we subsidizing oil companies? Why at COP 26 did representatives of oil and gas have more seats than the people actually running the conference? If we go to the root of it, it’s all about money-making, which brings me to my second point.

We are stuck in a lens that we view economic growth through, and we have been for years. When we think of economic benefits, we think of it only from a monetary stance, but there’s much more to it. Climate change drives the loss of biodiversity, and this underpins the economy, so although it’s less quantifiable from a monetary point of view, it’s incredibly significant to consider — now more than ever. You can read an opinion piece I wrote on this topic here.

The final point I wanted to bring up is thinking about the notion of epistemological pluralism. We need to understand these matters from different perspectives. The Indigenous people, for example, have been thinking about this for thousands of years and they have ancestral knowledge that is available to all of us. Although we’re just coming to such a realization, this is something where we need diversity of opinion. There is a great article by BBC on how Indigenous knowledge could save the Great Barrier Reef here.


Many people have anxiety around climate change, especially youth, because decision-makers are letting down our generation, but what we have to do is take our eco-anxiety and turn it into eco-action. We all have individual agency so whether it’s writing to your MP, doing things in your school to raise awareness, or getting involved in research projects, we can all become agents of change.

Thank you so much for reading this! I’m a 15-year-old passionate about sustainability, and am the author of “Chronicles of Illusions: The Blue Wild”. If you want to see more of my work, connect with me on LinkedIn, Twitter, or subscribe to my monthly newsletter!