The global population is tipped to surge 24 per cent by 2050, from 7.5 billion to 9.8 billion.
According to IKEA's latest sustainability report, People and Planet Positive 2017, the ageing population is one of the reasons for the rapid growth.
According to the report, 22 per cent of the world will be aged over 60 by 2050, up from 11 per cent recorded in 2012.
It will be the first time in human history that the elderly population outnumbers the youth.
According to the report, more than 60 per cent of Australians aren't ready for an increased population and almost 70 per cent believed Australia was not prepared as a nation.
The report made some predictions about how drastically the country will have to change to be able to cope.
THERE'LL BE NEW CITIES
To cope with the growing population, the report said Australia would need to create a number of new cities as people will start flocking to cities from regional areas.
According to the UN, 70 per cent of the world's population will live in cities by 2050.
Simon Caspersen, from future-living innovation lab SPACE10, said to handle a 9.3 billion population over the next 40 years, there'd need to be new cities established quickly.
"To put it into perspective, that's around six new cities for six million people every month," he said.
"With urbanisation accelerating, there will be increasing pressure on natural resources like water, air, energy and food.
"This means the built environment needs to incorporate elements like spaces to grow food, systems to recycle waste and water, natural cooling and heating mechanisms and design that facilitates all of this."
EVERYONE WILL HAVE HOUSEMATES
IKEA sustainability manager Kate Ringvall told news.com.au urbanisation was a key trend that would affect the way we lived in the future.
"A likely scenario, we believe that the future will be more about 'co-living' - a shared economy where we make do with less space, surrounded by more people.
"From a retail perspective, we will continue to adapt our home furnishings to suit these
future spaces. We expect to see smaller spaces, with clever storage solutions, greener
spaces in our environments - inside and out - and home furnishings solutions which will be better for people and the planet.
SPACE10's Xuan Teo said in the report co-living was the way of the future.
"The rise of the so-called sharing economy, coupled with the planet's rapidly depleting resources and fast-growing population, is forcing us to rethink the concept of ownership and sharing in our everyday lives, including in housing," he said.
"In the future we may have to get used to living with other people - but what opportunities might cohabitation offer us? And what is it about shared living that could persuade us to give up our privacy and redefine what we mean by home?"
WE'LL ALL BE FARMERS
To cope, most of us will start growing our own food.
IKEA sustainability manager Kate Ringvall said in the report that the retail giant was developing its range to make sustainable living easier.
"From bins with built-in recycling sections, to mini greenhouses to help people grow their own herbs and vegetables at home - our goal is to facilitate an eco-friendly lifestyle," she said.
SPACE10 has already teamed up with architects to create The Growroom, a spherical greenhouse where plants are stacked in tiers to maximise space and water flow.
The report said The Growroom was designed for cities with a spatial footprint of 2.8 by 2.5 metres.
"It is designed to create a sense of everyday wellbeing by providing a green oasis where people can connect with nature and smell and taste the abundance of herbs and plants," the report said.
The urban garden will be in Australia for the first time on Wednesday at Hickson Road Reserve in Sydney.
"The experience will bring to life a glimpse in to the future, as we hope to educate Australians on what the future may look like in a 'co-living' scenario," Ms Ringvall told news.com.au.