A new study published in PLOS Biology paints a concerning picture of the world's coral reefs. If we don't take action to address the climate crisis, half of these fragile ecosystems could face "unsuitable" conditions by 2035.

The findings are even worse than anticipated, as the negative impacts of climate change interact with multiple stressors, according to lead author Renee O. Setter from the University of Hawai’i.

The fact that coral reefs are in trouble is no secret, and they have long been vulnerable to the climate crisis, and between 2009 and 2018, 14 per cent of the world's reefs were lost due to its effects. Even if we manage to limit global warming to 1.5 degrees Celsius above pre-industrial levels, the Intergovernmental Panel on Climate Change warns that 70 to 90 per cent of tropical reefs could still be wiped out.

What sets this new study apart is its focus on how different stressors interact to harm coral reefs. The research team considered five key stressors: sea-surface temperature, ocean acidification, tropical storms, land use pressures, and human population pressures. By examining how these stressors combine, they sought to understand when and how the reefs would face unsuitable conditions.

In the worst-case scenario, where we continue with business-as-usual emissions, just one stressor would push half of the reefs into unsuitable conditions by 2050. However, when multiple stressors were considered, the timeline accelerated significantly. By 2035, half of the world's reefs would already be in jeopardy. Even under the best-case emissions reduction scenario, the difference was stark, with 41 per cent of reefs facing unsuitable conditions by 2100 when considering only one stressor, but 64 per cent facing the same fate when multiple stressors were accounted for.

The outlook for the worst-case scenario is even bleaker. By 2055, 99 per cent of reefs will face unsuitable conditions due to at least one stressor, and by 2100, 93 per cent will be threatened by two or more stressors. These alarming projections call for urgent action from scientists and conservationists to protect coral reefs.

The study emphasises that we must promptly address available solutions to human disturbances. While the research has global implications, it is significant for local Hawaiian reefs, vital for biodiversity, island culture, fisheries, and tourism. Erik Franklin, one of the study's co-authors, highlights the regional consequences, urging us to recognise the importance of protecting these reefs.

In their next steps, the research team plans to investigate the vulnerability of individual coral species to further comprehend their specific risks in the face of the climate crisis. 

It is crucial that we act swiftly and decisively to save these precious and vulnerable ecosystems before it's too late.

The clock is ticking, and the fate of coral reefs depends on our collective efforts to address the climate crisis and protect their future.