Professor Hugh Possingham says authorities must confront prospect that some parts of reef are doomed and focus on what to preserve

This article is more than 4 years old

This article is more than 4 years old

Governments must decide which parts of the Great Barrier Reef they most want to save and confront the prospect that some of it may be doomed, an expert on conservation modelling has warned.

University of Queensland professor Hugh Possingham said agencies, including the Great Barrier Reef Marine Park Authority, needed to make tough decisions about which parts of the natural wonder are most worth preserving “rather than trying to save everything”.

Possingham said the looming “triple whammy” of global warming’s impact on the reef – warmer seas, more acidity and more cyclones – meant time was running out and “triage” priorities were needed.

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“We should be identifying the most resilient places – the ones most likely to be able to deal with all these assaults from outside and focusing our attention on them rather than trying to save everything,” he said.

“We need to focus on the bits we can definitely save.”

Possingham, a former Rhodes scholar who is described by the Australian Mathematical Sciences Institute as “the global leader in mathematical modelling and decision science for nature conservation”, conceded it could be “suicide” for politicians to talk of abandoning some parts of the reef over others.

“In politics, there’s a lot of: ‘We can do everything’,” he said.

But a “difficult discussion” was needed with time running out for more research, limits on funding, and the real chance of a “Sophie’s choice” looming for the reef, Possingham said.

“I’ve been asking the GBRMPA and other people several times, what is their plan if things keep going the way they’re going?” he said.

“Are there particular reefs they want to protect? Are there particular sections of reefs? Do they want a few good reefs and lots of degraded reefs? Or do they want everything somewhere in the middle?

“I think it’s a difficult discussion. [But] I would prefer on the environment side that all levels of government have much clearer and more specific objectives and that they would acknowledge that they have to make trade-offs.”

Possingham’s work, including on software for systematic conservation planning, has been hailed as “the most significant contribution to conservation biology to emerge from Australia’s research community”. It has been instrumental in extending marine reserves around the reef.

He was also co-author of “The Brigalow Declaration” which prompted the Beattie state government to bring in a land-clearing ban that helped Australia meet its Kyoto protocol target on carbon emissions.

Possingham said while he welcomed the presence of climate sceptics, it would be “catastrophic” to delay action until the full consequences of how global climate change will play out and coral reefs would evolve were known.

“The person who creates the burden of proof has always got the upper hand because it’s almost impossible to prove anything entirely when we’re talking about large landscapes and seascapes over long periods of time,” he said.

“Technically we’ll never know everything [but] we can’t wait and we’ve got to get to a point where reasonable evidence is enough evidence.”

Possingham said the reef needed an analysis on the most effective steps to preserve it “per unit dollar of activity from the government”.

The same kind of modelling, which involves crunching numbers using “mathematics, statistics, economics and ecology”, has been done at Monash University and elsewhere to work out the cheapest way to reduce carbon emissions.

The analysis applied to carbon emissions, which drive climate change, the reef’s main threat, shows Australia sacrificing less than most other countries to go carbon neutral, Possingham said.

That put the onus on Australia to act, even though the reef’s fate through climate change will be “not entirely, but largely driven by the activities of other countries”.

Australia could go carbon neutral by 2030 “with far less pain than most people think and the average Australian would barely notice the difference”, Possingham said.

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“My view is Australia is a filthy, filthy, filthy rich country … if we can’t make a small sacrifice, I don’t see why people in Bulgaria, Brazil, or Columbia – people who enjoy a far lower standard of living than we do – should do it,” he said.

The key threat to the reef within Australia’s control was sediment and chemical run-off, from grazing and agriculture, that can damage coral and trigger harmful crown of thorn starfish outbreaks.

Looking at the most cost-effective ways to tackle the problem through government funding would lead to a dramatic cut in the number of landholders who received assistance or payments to reduce harmful runoff, Possingham said.

“We know that 90% of the nutrients are coming from probably 10-20% of the properties,” he said.

“So if you wanted to target the money to the places that will deliver the greatest benefits to society, it would not necessarily be equitable, but you would achieve a lot more per unit dollar.”

The federal Coalition, poised again to take office, has pledged up to $1bn in loans for water quality projects linked to the reef, which other conservation experts have said is nowhere close to what’s needed.

Possingham said the challenge of choosing some reef parts over others was that conservation was not guaranteed “given the randomness in coral bleaching and cyclones” and which parts of the reef they affected.

“It’s a bit like going into the casino and playing blackjack (but) blackjack is the one game where you can tolerably make a small profit for a short period of time,” he said.

Possingham will be giving a public address on the “numbers game” of conservation and environmental management challenges at the Edge, State Library of Queensland, on 11 July at 6.30pm as part of the Australian Mathematical Sciences Institute Winter school.