Imagine losing forever all video footage of your children growing up. As a nation, Australia faces an equally unthinkable prospect. A substantial component of our 20th-century audiovisual cultural heritage – documenting our growth as a nation – will disappear by 2025 due to deterioration of the magnetic tape on which it is stored.

On UNESCO World Day for Audiovisual Heritage – 27 October – National Archives Director-General David Fricker has highlighted the urgency to save this irreplaceable material before it is lost.

As the keeper of the memory of the Australian Government, the National Archives holds the largest collection of audiovisual records on magnetic tape in Australia, and is tasked with preserving this material and making it accessible for future generations.

From Countdown and Playschool to ASIO surveillance, Antarctic exploration, Indigenous customs and language, secret military operations and censored movie footage – the National Archives' collection of magnetic media represents the unique and irreplaceable memory of our nation and the evidence of the actions and decisions of the Australian Government.

Across the world, experts agree that magnetic tape which has not been digitised by 2025 will be effectively lost forever due to degradation or technological obsolescence. The solution is preservation through mass digitisation of the magnetic tapes.

The National Archives holds close to 950,000 film, audio and video items of which 28 per cent is on magnetic media. To date the National Archives has digitised approximately 75,000 audio and video items on magnetic tape and continues to prioritise this significant preservation work. However, 190,000 individual audiovisual items remain at risk of loss, and time is running out.

The National Archives estimates that it will cost $25 million to save this priceless heritage material. David Fricker, National Archives Director-General says, 'Knowing that this precious collection is at risk, it is difficult to overstate the urgency to act now to preserve and keep accessible these records that belong to future generations of Australians. Without decisive action now the heartbreaking prospect of losing a substantial part of the memory and evidence of the events and decisions that shaped our nation could soon become a reality.'