Record-breaking ocean temperatures have triggered an ongoing mass bleaching event that is endangering nearly three-quarters of the world’s coral reefs, the U.S. National Oceanic and Atmospheric Administration’s (NOAA) Coral Reef Watch reported last month.
This is another warning of the climate crisis, the effects of which are being felt most by the working class and the poor around the world as global temperatures, including in the oceans, continue to rise.
The current global coral bleaching event (GCBE4) is the fourth ever recorded and has been ongoing since February 2023. NOAA officially declared it in April 2024. Bleaching has affected coral reefs in all major ocean basins and nearly 70 countries, including the United States (particularly in Florida), Brazil, Panama, Costa Rica, Tuvalu, Fiji, and Australia.
Coral bleaching occurs when the corals are no longer able to support vital symbiotic microorganisms called zooxanthellae. These zooxanthellae algae provide the corals with essential nutrients without which they cannot survive for long. When the surrounding water temperatures exceed the thermal limit that allows this symbiotic relationship, the coral sheds the algae, turning the organism white, a process called bleaching.
The last such event – GCBE3 – occurred from 2014 to 2017 and affected 65.7 percent of the world’s coral reefs. GCBE4 has left 72.9 percent of coral reefs at risk of coral bleaching, according to the latest figures from mid-July, making it the most widespread event on record. It is on track to be the worst, with NOAA having to implement three additional new heat alert levels since GCBE3.
One example is Australia’s Great Barrier Reef (GBR) – the world’s largest coral reef – which was affected by GCBE4. In 2016, the WSWS warned of the consequences of the devastating coral bleaching event that year, which killed almost 70 percent of the GBR’s shallow-water corals.
Since then, four mass bleaching events have wreaked havoc on the health of the GBR, with the most recent event emerging as the most catastrophic of all. A recent study published in Nature found that ocean temperatures in the GBR are higher than at any time in the past 400 years. It said: “The existential threat to the GBR ecosystem from anthropogenic (human-induced) climate change is now recognized.”
In August 2023, an all-time high for global sea surface temperature (SST) was reached at 20.98 °C. These temperatures have maintained, with measurements in June 2024 reaching 20.85 °C. On average, Earth’s oceans have warmed by about 0.88 °C since 1850.
This latest global catastrophe confirms years of warnings by scientists that coral reefs are increasingly being destroyed by heat stress caused by climate change, according to a 2007 paper published in the journal Science stated that corals are becoming “increasingly rare in reefs” due to global warming expected in the 21st century. The authors warned: “Decisive action on global emissions is needed to prevent the loss of coral-dominated ecosystems.”
Although natural climate fluctuations such as the El Niño-Southern Oscillation phenomenon are responsible for these high temperatures, there is no scientific doubt that the main cause is climate change caused by greenhouse gases resulting from the burning of fossil fuels.
The health of coral reef systems is critical to the ecological functioning of the entire planet. Coral reefs are home to 25 percent of all marine species. In addition, approximately six million people around the world, mostly in impoverished countries, depend on coral reef fisheries for their livelihoods.
These ecosystems also play an important role in minimizing other environmental impacts for millions of people around the world. Coral reefs absorb the worst effects of storms and floods in the world’s coastal areas. Globally, 100 to 200 million people living in these areas are at least partially protected from such hazards by coral reefs.
With higher temperatures caused by climate change, bleaching events have become five times more frequent than they were four to five decades ago, reducing the time between bleaching events in which corals would otherwise have time to recover.
Dr Emma Camp, leader of the Future Reefs team at the University of Technology Sydney, explained: “If given a chance, corals are actually resilient and can recover. But as coral bleaching becomes more frequent and more intense, that window of opportunity is getting smaller and smaller.”
These climate events, which are already causing great concern among scientists and people around the world, occur at a global warming of about 1°C. Due to completely inadequate commitments by governments, the world is on track for warming of 3°C above pre-industrial levels by the end of the century.
The 2022 report of the Working Group II of the United Nations Intergovernmental Panel on Climate Change (IPCC), which summarized over 34,000 peer-reviewed publications, concluded that warming above 2°C is enough to threaten severe damage to over 99 percent of coral reefs.
Far from taking the necessary action to curb climate change, the ruling classes around the world have opposed any program that would save coral reefs. The Center for American Progress recently reviewed public statements by all sitting members of the U.S. Congress. It found that 23 percent “publicly deny the scientific consensus of human-caused climate change.” Many of them, including House Speaker Mike Johnson, receive hundreds of thousands of dollars in donations from oil and gas companies.
But climate change cannot be attributed primarily to the shortsightedness and corruption of individual politicians, parties or even governments. The real cause of climate change is the capitalist mode of production, which subordinates all social needs to private profit and divides the world into rival nation states.
A study published earlier this year by global consulting firm ICF estimates that a person born in the United States in 2024 could lose up to $1 million over their lifetime due to the impacts of climate change. Current and future generations of people will increasingly face “more difficult decisions about how to pay for food, shelter and other daily expenses.”
This average conceals the unequal burden on the working population, which is most affected by these impacts.
At the same time, fossil fuel companies like BP, Shell and ExxonMobil collectively rake in hundreds of billions of dollars in profits each year. Much of this wealth is not only hoarded by a small financial elite, but also used to buy back shares and enrich their investors. Ultimately, climate change is an issue that once again demonstrates the class divide that drives the threat to human civilization.
The crucial lesson we can learn from the bleaching, the wider threat of climate change and the response of governments is that the capitalist classes are powerless to avert ecological catastrophe. Only a united movement of the international working class to overthrow the profit system and reorganise society on a socialist basis can adequately protect these vital ecosystems and avert planetary catastrophe.
