By 2035, half of the world's coral reefs could face unsuitable environments

If climate change continues, there is more bad news
for the planet.
In a new study published Oct.
11, researchers at the University of Hawaii in the United States revealed that in a worst-case scenario, half of the world's coral reef ecosystems would be permanently exposed to unsuitable environments
for just a dozen years.

The ability of ecosystems to adapt to changes in their environment depends to a large extent on the type and impact
of their specific environmental stressors.
Coral reefs are particularly sensitive to
these unsuitable environmental conditions.
However, the timeline for environmental suitability has been controversial
.

Using CMIP5, an experimental framework designed to calculate global models designed to improve knowledge of climate change, the researchers looked at global projections of five environmental stressors, from historical scenarios to 2100 projections
.
These stressors include sea surface temperatures, ocean acidification, tropical storms, land use, and population projections
.

"While the negative impacts of climate change on coral reefs are well known, this study shows that they are actually worse than expected due to a broad mix of climate change-induced stressors," said study lead author Renee Setter, a doctoral student
at the University of Hawaii in Manioa.
"We also found that corals will face multiple stressors, which is an even bigger obstacle and challenge that needs to be overcome to increase the likelihood of
survival.
"

Seth and his colleagues found that in a business-as-usual scenario, 2050 is the median year
when environmental conditions are expected to become unsuitable for the world's coral reefs, given a single stressor.
If multiple pressures are taken into account, this date will be reduced to 2035
.
In addition, it is predicted that by 2055, most of the world's coral reefs (99%) will face unsuitable conditions
, according to at least one of the five stressors studied.
It is estimated that by 2100, 93% of the world's coral reefs will be threatened
by two or more stressors identified by researchers.

"We know that corals are vulnerable to rising sea surface temperatures and ocean heatwaves caused by climate change
.
But to better understand the overall risks to these ecosystems, it's important to expose coral reefs to entirely anthropogenic impacts and numerous stressors," added co-author Eric Franklin, an associate research professor
at the University of Hawaii.
"This has a big impact on our local Hawaiian coral reefs, which are key to
local biodiversity, culture, fisheries and tourism.
"

The research team is now preparing to move on to the next phase of its work
.
They will further study the impact
of climate change on individual coral species.
By identifying which species are more likely to survive in unsuitable environments and which may be more vulnerable, the team hopes to better understand which species may be more vulnerable to future stressors
.