'Cloud brightening' could help Great Barrier Reef

Using experimental “cloud brightening” technology and introducing heat-tolerant corals could help slow the Great Barrier Reef’s climate change-fueled decline by up to 20 years, Australian scientists said on Thursday.

The reef faces “precipitous declines” in coral cover over the next five decades due to “intense pressure” from climate change, a study published in the peer-reviewed journal Royal Society Open Science said.

Climate change is causing marine heatwaves, more intense cyclones and flooding — all of which are damaging the health of the reef.

“Coral reefs are some of the most climate-vulnerable ecosystems on Earth,” lead author Scott Condie said.

“The model projections suggest that coral cover on the Great Barrier Reef could fall below 10 percent within 20 years.”

But ambitious human interventions combined with “strong global climate action” could slow the rate of decline, said Condie, a senior research scientist at the government’s science agency, the CSIRO.

The Great Barrier Reef has already suffered three mass coral bleaching events in five years and lost half its corals since 1995 as ocean temperatures have climbed, according to separate research.

Condie and his co-authors modeled the potential impact of interventions such as “cloud brightening,” which was first trialed on the reef last year.

The technology sends salt crystals into the air, making clouds reflect more sunlight to cool waters around the reef.

They also modeled expanded measures to control the predatory crown-of-thorns starfish, which consume the corals and proliferate when bleaching forces bigger fish to leave an area.

“The results suggest that combinations of interventions may delay decline of the Great Barrier Reef by two decades or more,” Condie said.