Scientists have singled out New Zealand as a potential "ark" to reboot civilisation if a deadly pandemic swept the planet.
In a study just published in the international journal Risk Analysis , researchers found that New Zealand, along with Australia and Iceland, could serve as "lifeboats" to help humanity recover from a full-scale extinction event.
One of the authors, Professor Nick Wilson of Otago University, said that threat had never been higher, with the threat increasing as technology advances.
"Discoveries in biotechnology could see a genetically-engineered pandemic threaten the survival of our species," he said.
"Though carriers of disease can easily circumvent land borders, a closed self-sufficient island could harbour an isolated, technologically-adept population that could repopulate the earth following a disaster."
To identify those best islands to prepare as refuges, the researchers devised a scoring system taking into account the characteristics of each island nation's population, location, resources and society.
The results showed Australia to be the most favourable refuge on paper, because of its vast oversupply of energy and food.
It was closely followed by New Zealand and then Iceland.
The researchers ranked island nations with populations of more than 250,000 as possible refuges, considering that the larger the population, the more likely it was that the refuge would ultimately be able to reboot global civilisation.
Wilson said it was important to consider in advance how to mitigate low-probability but disastrous scenarios such as an extinction-level pandemic.
"It's like an insurance policy. You hope that you never need to use it, but if disaster strikes, then the strategy needs to have been in place ahead of time."
The lead author of the study, Dr Matt Boyd, research director at Adapt Research, said humans could wittingly or unwittingly unleash a modified organism with the potential to kill all of humankind.
"The worst case scenario could see multiple genetically engineered pandemic organisms being released at once.
"We need to be ready for these situations. Our study shows that certain island nations have the characteristics needed to preserve technological culture through a catastrophic event."
Boyd said International Health Regulations (IHR) generally didn't support border closures in pandemic situations.
However, the scenarios the IHR assumes are not existential threats to humanity, he said.
"It may be that a clear and pressing need arises where the only option for humanity is an island refuge."
The researchers say that for such a strategy to succeed, preparations must be made ahead of time.
They suggest that New Zealand consider investing in resiliency measures and rehearse the rapid introduction of border controls.
Previous research by the same authors has shown border closure to be a cost-effective measure in major pandemic situations, where thousands of New Zealanders could potentially die, such as in a repeat of the 1918 flu pandemic.
Wilson said New Zealand could also collaborate on planning with other island nations that are most likely to be able to survive a pandemic threat, such as Australia.
"Resiliency planning could also take account of other threats, such as a nuclear war in the Northern Hemisphere, which New Zealand is also relatively well-positioned to survive."