Beyond the Bleach: Imagining Life After Coral Reefs in a Warming World.

The fate of the world’s coral reefs has become one of the most certain outcomes in climate science. With global temperatures on track to rise by 1.5 degrees Celsius within the next decade, scientists warn that most coral reefs could be lost—an ecological transformation with wide-reaching consequences.

According to David Obura, chair of the UN’s Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), it is time to stop hoping for a full recovery and start planning for what comes next. “We need to be pragmatic about it,” said Obura, who is also the founding director of the marine research organization CORDIO East Africa. “Let’s be honest about where we are and deal with the consequences.”

The emotional weight of this potential loss is heavy among marine scientists. Melanie McField, a Caribbean reef specialist and director of the Healthy Reefs for Healthy People Initiative, described a collective sense of "pre-traumatic stress syndrome" in the scientific community. “It’s hard to imagine a future without coral reefs,” she admitted, “but it’s likely in the two-degree world we are rapidly heading toward.”

The mechanism behind this collapse is well understood. Corals are highly sensitive to heat. When ocean temperatures rise, they expel the symbiotic algae that give them both their color and primary food source. This bleaching leaves corals vulnerable, and without recovery, they eventually die.

The Intergovernmental Panel on Climate Change (IPCC) estimates that 70 to 90 percent of coral reefs will be lost at 1.5°C warming. At 2°C, that figure climbs to a devastating 99 percent. Even now, with global temperatures approximately 1.4°C above pre-industrial levels, widespread coral bleaching events are already unfolding—potentially marking the start of a global collapse of tropical reefs.

Rather than vanishing completely, coral reefs are expected to evolve into new types of ecosystems. The slow-growing hard corals that build reef structures are likely to disappear first, leaving behind skeletal remains. These remnants will eventually be colonized by algae, sponges, mussels, and more resilient soft corals like sea fans.

“It won’t be the same vibrant reef ecosystem,” explained Tom Dallison of the International Coral Reef Initiative. “There will be more losers than winners.” The structural remains of dead coral—eroded by acidifying oceans and battered by storms—will degrade into underwater rubble over time.

Still, these altered ecosystems may continue to provide some ecological and economic functions, such as habitat for marine life, coastal protection, and limited tourism potential—if properly managed. “They will still exist, but they will look very different,” Dallison said. “Our responsibility is to protect the services they offer.”

The stakes are enormous. Coral reefs are home to roughly a quarter of all ocean life and support about one billion people globally through fisheries, tourism, and shoreline defense. Their decline, therefore, is not just an ecological issue—it is a socioeconomic crisis in the making.

Despite the urgency, much of the research has focused on reef conservation and climate resilience strategies rather than on preparing for post-reef futures. Resource limitations have slowed exploration of what these transformed ecosystems might look like.

While global warming is the chief driver, other threats—like pollution, overfishing, and harmful subsidies—also contribute to reef degradation. Addressing these issues, Obura emphasized, could give remaining reefs a better chance of surviving whatever warming the planet experiences.

Jean-Pierre Gattuso, an ocean scientist at France's CNRS, agrees that saving reefs is a steep challenge while carbon emissions continue. However, he pointed to efforts focused on identifying and restoring heat-tolerant coral strains as a possible beacon of hope.

“How do we keep going when we know what’s coming?” Dallison reflected. “The answer is to find ways to make that dark future a little less dark."

Source:https://phys.org/news/2025-06-hotter-future-coral-reefs-die.html

This is non-financial/medical advice and made using AI so could be wrong.