Professor Emma Johnston says the independent State of the Environment report has been with federal Environment Minister Sussan Ley since last year.
She says the rigorous assessment commissioned by the government is released every five years for a reason, and time is of the essence in the face of escalating, extreme events.
The report is an evidence-based audit of environmental health. It also assesses how well ecosystems are being managed amid climate change, habitat loss and other pressures. It's purpose is to inform policing making and protection efforts.
Conservation groups and the Morrison government's political rivals are among those demanding the report's release before the federal election, with some suggesting it will be bad news and accusing Ms Ley of sitting on it.
Prof Johnston, whose expertise is in marine ecology, says the report for the first time includes a dedicated chapter on extreme events.
"The reason, obviously, is that the influence of extreme events has become so much more apparent over the last five years," she says.
"Sometimes I felt like I was just cataloguing disasters, the reef bleaching, and the big floods and the bushfires. Things are changing so quickly we have run out of time, so we need to move fast."
Prof Johnston is one of three co-chief authors of the milestone 2021 report, which she said was handed to the federal minister in December. It has taken two years to produce with contributions from a total of 32 experts.
"We are looking forward to seeing the report out as soon as possible so it can be used not only by government but also by industry and community groups."
A spokesperson for Ms Ley says the minister will act in accordance with statutory requirements, which require her to table the report in parliament within 15 sitting days of receiving it.
Critics say that with an election imminent, Australians could be denied an independent assessment of five years of management by the coalition before they must vote.
The last State of the Environment report, which looked at the five years up to 2016 found environmental policies and management practices, had achieved improvements parts of the Australian environment.
But some parts were found to be poor and deteriorating, including more populated coastal areas, urban environments, grazing lands where biodiversity was threatened.
