“How smart is Smart Growth?”
Why focus on Social-Ecological Urbanism? • Continuing population growth and urbanization are projected to add 2.5 billion people to the world’s urban population by 2050 (United Nations 2014) • It has been projected that by the year 2030, the global urban land cover will nearly have tripled in comparison to that in the year 2000 (Seto et al. 2012) • Due to the current rate of urbanization the competition for alternative land use is fierce and will be even more so in the future (Olofsdotter et al. 2017) • Ecosystem services are the work of nature upon which all socio-economic activities rely • Ecosystem services are being eroded and used unsustainably (MA 2005) • The role of urban ecosystems for sustainable (urban) development (CBO)
(Elmqvist et al. 2013)
Key messages • Maintaining functioning urban ecosystems can significantly improve human health and well-being • Ecosystem services must be integrated in urban policy and planning • Cities offer unique opportunities for learning and education about a resilient and sustainable future
The Smart Growth (SG) concept • SG strives for compact, transit-oriented, walkable, bicyclefriendly land use, including mixed-use developments • SG has emerged as a response to the ineffective and unsustainable patterns of urban growth (sprawl) • The SG-approach aims at safeguarding against more remotely located ecosystems being transformed into urban fringe development, which threatens prime farmlands, wetlands, and unique wildlife habitat • Based on the above assertions, SG is widely adopted by urban planners and policy makers as the most environmentally friendly form of building cities • In Stockholm the dominant strategy for urbanisation is densification (RUFS 2018)
Same density, different forms!
Is dense smart? How dense is smart? How do we measure it? What about the environmental gains?
Material and method • A scientific literature review on SG was conducted through a
systematic search for scientific publications using the Scopus and Web of Knowledge databases
• January 1985 to May 2017 • The initial search for articles yielded 150 articles for abstract screening. • 105 articles were selected for full article screening • 29 articles used for the review (empirical and quantitative connection to environmental gains)
Materials and methods Data deduced from the 29 articles, including: • year of publication, • geographical location of the empirical data • scale(s) addressed: micro (at the level of individual buildings); meso (at the block- and neighborhood level); and macro (at the level of a city) • the definition of SG • identification of characteristic attributes of SG • techniques for measurements of such attributes
Results I
Results II Five environmental parameters identified
Results III • We found that a surprisingly limited number of studies have actually examined the environmental rationales behind SG, with 34 % of those studies displaying negative environmental outcomes of SG.
• The studies that do show positive relationships, do so based on a restricted number of environmental parameters, mainly confined to the mitigation of CO2 emissions by reduced private transportation
Results IV • Decrease CO2 emissions (less car travel) -Positive if excluding “leisure trips” • Saving open space outside -Positive if ignoring that green areas IN the city are used up • Air quality -Positive on a regional scale, negative on a local scale • Habitat for biodiversity Negative (very few studies) • Reduced temperature (UHI) -Positive if assuming that “sprawl” removes most green areas • Many ES are not addressed: e.g. food production , pollination, physical and mental health and social cohesion in relation to urban green areas (cultural ecosystem services)
Conclusion: The scientific foundation for environmental gains in relation to SG is inconclusive!
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To remedy this, SG research needs to: be founded in more advanced and consistent knowledge in geographical and spatial analysis to a greater extent start from a social-ecological systems understanding of urban processes
Thank you! asa.gren@beijer.kva.se http://www.beijer.kva.se/ http://www.stockholmresilience.org/