Coalition backs 'cloud-brightening' trial on Great Barrier Reef to tackle global heating

Graham Readfearn
·5-min read

A government-backed research program to make the Great Barrier Reef more resilient to global heating will spend $4.7m this financial year developing technologies that could shade corals and make clouds more reflective during marine heatwaves.

The announcement confirms the development of a technique known as marine cloud brightening, trialled on the reef in March, will be backed as part of the government’s $443 grant being coordinated by the not-for-profit Great Barrier Reef Foundation.

On Tuesday the government and the foundation announced how it would spend $96m this financial year under the Reef Trust Partnership – the $443m collaboration between government and the foundation.

Related: ‘A mockery’: Great Barrier Reef Foundation raises just $21m of $357m target

Included in the spending for this financial year is more than $15m to try and control coral-eating crown-of-thorns starfish, $39m to improve water quality and more than $3m for community-based projects, including citizen science.

Earlier this year the reef suffered its third mass coral bleaching event in five years. About one quarter of the reef suffered severe bleaching in the most widespread event ever recorded, affecting the full length of the 2,300km world heritage marine park.

Dr Daniel Harrison of Southern Cross University is the scientific lead for the $4.7m program to investigate cooling and shading techniques.

Harrison told Guardian Australia: “We want to know if this will work, and we want to know as quickly as possible.

“It’s critical that [greenhouse gas] emissions come down, but that alone won’t preserve a lot of the ecosystem value of the reef so we need to do other things as well.”

About half of the $4.7m will be spent developing atmospheric modelling and monitoring to understand how particles in the air that clouds need to form behave over the reef.

In-kind support of $1.86m from a consortium of academic institutions led by Southern Cross University, including the CSIRO, will be added to the $4.7m.

Guardian Australia revealed that in March Harrison led a small research team to trial cloud-brightening equipment on Broadhurst reef near Townsville.

In the experiment, a modified turbine with 100 high-pressure nozzles was placed on the back of a boat to spray trillions of nano-sized salt crystals into the air.

When deployed at a larger scale, those salt crystals theoretically mix with low-altitude clouds to reflect more solar energy away from the waters around the reef.

Brightening clouds could work on a scale large enough to both shade corals and cool sea surface temperatures that could be the difference between corals dying from bleaching or recovering.

A technique known as fogging will also be developed over the coming 12 months. Using a similar deployment technique, larger droplets create localised fog that would aim to give some protection to individual reefs or groups of reefs that hold particular importance, either because of their cultural values, importance to tourism, fishing or for their biodiversity.

Harrison said atmospheric modelling and surveying would be used to check whether the cloud-brightening approach could have any wider impacts. Engineering facilities would also be built.

He said the cloud-brightening approach, if proven, would be deployed over the course of a month or two if temperatures got too high. The fogging technique would be used over a shorter time frame.

He said both approaches could be switched off rapidly and the salt crystals remained in the air for only a day or two depending on conditions.

Announcing the $96m of spending for the year, environment minister Sussan Ley said: “Over the next 12 months we will be testing new approaches and technologies to protect and preserve the Great Barrier Reef, building on the partnership’s key on-ground achievements from its first two years of operation.”

Anna Marsden, managing director of the foundation, said there were “more than 60 reef-saving projects” under way in regional Queensland.

She said: “The significant investment of $96m will mean that two-thirds of the $443m partnership will have been committed to reef-saving projects within a year.

Related: Unesco urged to declare Great Barrier Reef 'in danger'

“Saving the reef is a huge task, but there is hope. We are proud to be doing our part to bring together people and science to deliver outcomes that will preserve the reef in the face of growing threats.”

The foundation has a target to raise $357m in donations to top up the government funding, but Guardian Australia revealed last week that only $21.7m had been raised so far.

A world heritage committee meeting scheduled for early July this year in China has been postponed, but was to consider if the reef should be placed on an “in danger” list.

Australia has already conceded that climate change has caused damage to the unique attributes that led to it being listed as a world heritage site in 1981.

Greens senator Larissa Waters criticised the work plan for this financial year, saying it “talks about the need to tackle climate change and transition to clean energy, but does nothing towards that goal”.

She said plans to tackle crown-of-thorns starfish and shading the reef were “Band-Aid solutions”.

She said: “This work plan is more rearranging of the deck chairs on the Titanic by a federal government that ignores and worsens the climate crisis, and underfunds water quality improvement by orders of magnitude.”