Cities around the world are literally growing, and a new study suggests that as urban areas expand, they tend to reach skyward rather than sprawl.
While upward expansion has historically been limited to a handful of large cities such as New York and Tokyo, global high-rise development has expanded significantly over the past few decades. Yet, analyses of urban growth to date have generally stuck to traditional 2D models that cannot account for the increase in the number of high-rise buildings.
To address this issue, a team of researchers collected data on more than 1,550 cities from a satellite radar system that can measure the height of objects. The team found that, in general, the rate at which cities are expanding outward has slowed since the 1990s, while the rate at which they are growing vertically has accelerated. This held true across continents, but the trend was particularly pronounced in Asia.
The trend towards vertical development is accelerating in cities with populations over 5 million: in the 1990s, only 7% of land in these cities was occupied by high-rise buildings, but by the 2010s, that figure had risen to 28%.
The study was published in the journal Natural CityThe report not only offers a glimpse into the evolution of cities, but also valuable insights into how to improve urban life as more and more people move to cities. According to the World Bank, more than 56% of all humanity lives in cities. expect This is expected to increase to 70% by 2050. Building taller means higher population densities, with major implications for urban planning, including public services and the fight against climate change.
“Urban populations have nearly doubled since 1990, requiring increased transportation and infrastructure,” Steve Froelking, professor emeritus of geosciences at the University of New Hampshire and lead author of the study, said in a press release. “Urban growth affects greenhouse gas emissions and demand for specialized materials, and it also influences urban climates, creating microclimates – localized atmospheric conditions that differ from those in surrounding areas.”
If the idea of ​​sun-blotting high-rises conjures up disturbing images of a post-apocalyptic megalopolis à la “Judge Dredd,” Vancouver’s famously gentle residents may have a better idea.
