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Energizing Sustainable Cities: Findings from the Global Energy Assessment

October 24, 2013

Arnulf Grubler ImageOn Thursday, October 24, the Center for International Environment and Resource Policy (CIERP) hosted Arnulf Grubler of the International Institute for Applied Systems Analysis and Yale University, who presented on “Energizing Sustainable Cities: Findings from the Global Energy Assessment.” The lecture was part of CIERP’s ongoing Energy, Climate, and Innovation Research Seminar series. 

Grubler presented key highlights from Chapter 18 of the 2012 Global Energy Assessment (of which he was a lead author), noting the study was the “first international scientific assessment that explicitly addressed urbanization.” 

He began by addressing the rural versus urban debate on where to focus policy attention. Rural populations are expected to peak at 3.5 billion and decline after 2020, so “demand there is urgent.” However, Grubler argued, the main focus of sustainable energy policy should be on cities: “the dominant spatial form of human activity.” The world’s population is currently three-quarters urban, and that percentage will continue to grow.

GEA imageGrubler advocated the establishment of normative standards for reporting urban consumption, as a necessary prerequisite for analysis and policymaking. The Global Energy Assessment sought to address the measurement problem of cities—as “messy, open systems”—by proposing several definitions for quantitative research, such as land use, population, GDP, final energy use, light luminosity, internet routers, etc. Data indicated that in terms of land use, cities are relatively small, whereas by contrast, “the internet is essentially an urban structure.”

One surprising finding, given the extensive press coverage of megacities, was that small and medium cities are the true “workhorses of urbanization.” Grubler emphasized the need for more research on these cities, especially in Sub-Saharan Africa (specifically outside of South Africa), where current data is most limited, posing challenges for analytics and understanding. He argued that modern technology could provide a needed bridge to facilitate increased data collection in these areas.

His team compared the various quantitative metrics available for analysis. Notes Grubler, “The grid is ignorant of the electrons, and therefore the uncertainty of analysis lies in the openness of cities—each time we have a crossing of the border we have a huge measurement problem,” explaining why his team chose to focus on per capita direct final energy use, enabling researchers to distinguish between manufacturing and service-oriented cities. “Embodied energy flow” captures most urban energy use, but it includes both imports and exports of goods and services, thus double-counting some energy flows. Therefore, he cautions, we must “be very careful of overconfident scientific statements on the devastating effects of urban overconsumption.” 

In fact, Grubler’s research team found that city dwellers often have lower direct energy and carbon footprints than those in rural environments, and thus, cities are actually good for environmental sustainability. The driving forces behind this somewhat controversial finding are multi-fold: density, economies of scale, knowledge, diversity, and resource efficiency.

Most cities in highly developed countries (Annex I) have energy use below national averages, whereas cities in Annex II have above average national energy use. Rural residents in highly developed countries are inefficient energy consumers because of low density and high transport costs, whereas urban residents in Annex II countries have three- to five-times the per capita income of rural residents, and thus consume much more.

These findings underscore Grubler’s key message: that cities represent both specific sustainability challenges and opportunities. “The density prevailing in cities today is so high that we need to have zero emissions.” He argues this can be achieved by focusing on the point of consumption. Grubler cites the city of Vienna as one example of a district grid that is municipally owned and run, fed by waste incinerators located within city limits – but he cautions that there is still a mismatch in energy levels. Con Ed in Manhattan controls the biggest grid system in the world, which provides an opportunity to match consumption with available waste streams. “Each building can be its own micro-grid,” suggests Grubler.

A governance paradox leaves municipalities with little to no control over privatized services. As Grubler aptly notes, “Multi-level governance: nice word, very hard to do.” He characterizes the main sustainability challenge facing cities as a dual or inverse hierarchy, such that the leverage of urban scale policy is the largest on the issues of least importance. For example, urban renewables, which represent an area under municipal control, can contribute a maximum of only one percent of a city’s energy needs. 

This has significant policy implications, namely that those options in the middle of the scale represent the most favorable zone to target for reform. Modeling simulations support the idea that policy integration is needed to effectively address spillover effects, especially with regard to management of urban form and systemic change. Grubler argues for efficiency of energy end-use (in buildings, processes, vehicles, and appliances), and urban form (with regard to density as well as mix of public transportation and cars).

Furthermore, he notes the need to change the mindsets of policymakers with regard to informal settlements “outside” city limits. Grubler argues that so-called squatters or slum-dwellers should be regarded as legitimate residents, with a proactive plan to connect them to the city’s service grid. Again, he highlights the role technology could play in this process, suggesting the possibilities of remote sensing, cell phone data, etc.

Grubler posed a thought-provoking comment that ties nicely to CIERP’s upcoming lecture, “Road to Paris via Warsaw: A discussion on key issues in the lead up to the Warsaw Climate Change Conference,” so we’ll end with his suggestion, “Perhaps cities should be at the table when we move from Warsaw to Paris, and not the national governments?” 

Summary by Kathleen Yaworsky, MALD Candidate F'15