Scientists claim Great Barrier Reef could start disappearing in three decades

Australia's multi-billion dollar tourism industry is under increasing threat from climate change with The Great Barrier Reef predicted to start vanishing in 30 years, according to a new study by Gold Coast researchers.

Scientists found rising temperatures and sea levels created ocean acidity, causing coral to grow slowly and reef sediments to dissolve.

Southern Cross University's Professor Bradley Eyre said the acidity also threatened sea wildlife such as oysters, crabs and lobsters.

“We need to act now and act on governments globally to reduce Co2 significantly so we can offset this impact of ocean acidification,” he told 7 News on Friday.

A separate report by environmental advocacy group The Climate Council has revealed popular visitor destinations like the Great Barrier Reef were at risk, with major cities in coastal areas expected to face more frequent flooding in coming years.

The Climate Council pushed the government to do more to reduce carbon emissions harming the Reef, as well as Australia's beaches and national parks.

Tourism is the nation's second-largest export industry, valued at $40 billion and employing more than 580,000 people, it said.

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Australia's Red Centre region is also impacted, with predictions of more than 100 days annually above 35 degrees Celsius by 2030, The Climate Council study found.

"Tourists travel across the globe to see Australia's remarkable natural wonders, but these icons are in the climate firing line as extreme weather events worsen and sea levels continue to rise," ecologist and report co-author Lesley Hughes said.

"Some of our country's most popular natural destinations, including our beaches, could become 'no-go zones' during peak holiday periods and seasons, with the potential for extreme temperatures to reach up to 50 degrees in Sydney and Melbourne."

A separate report last year from Deloitte Access Economics valued the Great Barrier Reef as an asset worth $56 billion, which included its tourism revenues and its indirect value for people who have not yet visited but know it exists.

The World Heritage-listed site, which attracts millions of tourists each year, is reeling from significant bouts of coral bleaching due to warming sea temperatures linked to climate change.

"Without credible climate policy that cuts Australia's rising carbon pollution levels, the impacts of climate change will only intensify and accelerate across the country over the coming decades," Climate Council chief executive Martin Rice said.

Environmental advocates on Thursday urged Canberra to move away from coal-fired power generation.

With its heavy use of coal-fired power and relatively small population, Australia is considered one of the world's worst per capita greenhouse gas polluters.

"The extra heat from global warming will further reduce the tourist season and make some enterprises unviable," said Liz Hanna, from the School of Environment at the Australian National University.

"Protecting the tourism industry protects jobs and protects Australia's economic wellbeing."

Canberra insists it is taking strong action to address the global threat of climate change, having set an ambitious target to reduce emissions to 26 to 28 percent from 2005 levels by 2030.

Australia sweltered through its third-hottest year on record in 2017, with seven of its 10 warmest years experienced since 2005.