Climate change ‘to damage half of all coral reefs by 2035’

Potential impact ‘worse than feared’ due to broad range of threats

Half of the world’s coral reefs will be damaged by environmental stress by 2035, a new study reveals.

The researchers looked at global projections of five environmental stressors that can affect coral reefs.

These are sea temperature, ocean acidification, tropical storms, land use and human population projections.

Their results, published in the journal PLOS Biology, showed how little time it will take for coral reefs to be detrimentally damaged by these factors.

They found that if things continue as normal, environmental conditions are estimated to be unsuitable for coral reefs by around 2050 as a result of just one of these stressors.

When multiple stressors are considered, the date falls to 2035.

By 2055, they predict that 99 per cent of the world’s coral reefs will be suffering from unsuitable conditions based on at least one of the five stressors.

And by 2100, they anticipate that 93 per cent of these reefs will be under threat by two or more of the stressors identified.

Renee Setter, a doctorial student at the University of Hawai’i at Mānoa, and lead author of the study, said: “While the negative impacts of climate change on coral reefs are well known, this research shows that they are actually worse than anticipated due to a broad combination of climate change-induced stressors.

“It was also enlightening to find that coral would face multiple stressors – posing an even greater hurdle and challenge that would need to be overcome to increase the possibility of survival.”

Dr Erik Franklin, associate research professor at the University of Hawaii at Manoa, and co-author of the study, said: “We know that corals are vulnerable to increasing sea surface temperatures and marine heatwaves due to climate change.

“But it is important to include the complete anthropogenic impact and numerous stressors that coral reefs are exposed to in order to get a better sense of the overall risks to these ecosystems.

“This has great implications for our local Hawaiian reefs that are key to local biodiversity, culture, fisheries and tourism.”

Now, the team is set to prepare the next phase of their work. Researchers plan to look closer at how climate change is going to affect individual coral species.

Through these next steps, they will be able to discover which species are more likely to survive the unsuitable conditions and better understand which species may be more at risk to future stressors.

SWNS