The sustainable megacity

Every week, 1.5 million people move to towns and cities, putting huge demands on local resources and environments. Yet with the right techniques and technologies, urbanisation and sustainability can go hand-in-hand.

The megacities of the future

For the world’s growing population, the future is urban. It’s estimated that by 2030 there will be 41 “megacities” with more than 10 million inhabitants¹. Today there are just 18². The people in these cities will consume 81 percent of the world’s resources³. Twenty years later, by 2050, these urban populations will need 50 percent more food and 17 percent more water than they do today⁴. They will want to live comfortably, too. There are still 1.2 billion people without electricity today: tomorrow’s urban dwellers will want modern housing and energy, with a pleasant indoor climate.

This shift to cities comes at a cost. By 2050, current projections suggest that population growth and urbanisation will generate a two- to three-fold rise in global energy use for the building sector, with a similar impact on associated emissions⁵. When global environmental targets demand major reductions in energy use and CO₂ emissions, it’s hard to see how this urbanised world can be sustainable.

Tackling environmental challenges

Cities, however, present many opportunities to tackle environmental challenges. Apartments and offices that are renovated and built with high levels of insulation need much less energy to heat and cool than traditional structures, so it’s already possible to begin shrinking a city’s environmental footprint. For cities to use space efficiently, buildings often need to be taller and closer together, which can increase the risk of fire. Using non-combustible building materials such as stone wool insulation means that high-density living is possible without higher fire risk.

And meeting the need for food and water in growing cities necessarily demands more land and resources. With cultivation systems that use sustainable growing media to precisely target water and nutrients at crops, suppliers of food to urban populations can achieve big yields from small spaces.

The ROCKWOOL Group is at the forefront of developing materials that will help the cities of tomorrow to grow sustainably.

^{1 https://esa.un.org/unpd/wup/Publications/Files/WUP2014-Highlights.pdf
2 https://en.wikipedia.org/wiki/List_of_largest_cities
3 https://www.mckinsey.com/global-themes/urbanization/urban-world-the-global-consumers-to-watch
4 https://pubdocs.worldbank.org/en/862271433768092396/Holger-Kray-RO-SustainableAg-hkray-ENG.pdf 
5 https://www.gbpn.org/sites/default/files/IPCC_AR5__Implications_for_Buildings__Infographic__WEB_EN%20%281%29.pdf}