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The efficient, the intensive, and the productive: Insights from urban Kaya scaling

Gudipudi, Ramana and Rybski, Diego and Lüdeke, Matthias K. B. and Zhou, Bin and Liu, Zhu and Kropp, Jürgen P. (2019) The efficient, the intensive, and the productive: Insights from urban Kaya scaling. Applied Energy, 236 . pp. 155-162. ISSN 0306-2619.

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Urban areas play an unprecedented role in potentially mitigating climate change and supporting sustainable development. In light of the rapid urbanisation in many parts on the globe, it is crucial to understand the relationship between settlement size and CO_2 emission efficiency of cities. Recent literature on urban scaling properties of emissions as a function of population size has led to contradictory results and more importantly, lacked an in-depth investigation of the essential factors and causes explaining such scaling properties. Therefore, in analogy to the well-established Kaya Identity, we develop a relation combining the involved exponents. We demonstrate that application of this Urban Kaya Relation will enable a comprehensive understanding about the intrinsic factors determining emission efficiencies in large cities by applying it to a global dataset of 61 cities. Contrary to traditional urban scaling studies which use Ordinary Least Squares (OLS) regression, we show that the Reduced Major Axis (RMA) is necessary when complex relations among scaling exponents are to be investigated. RMA is given by the geometric mean of the two OLS slopes obtained by interchanging the dependent and independent variable. We discuss the potential of the Urban Kaya Relation in mainstreaming local actions for climate change mitigation.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Gudipudi, Ramana0000-0002-8758-9369
Rybski, Diego0000-0001-6125-7705
Liu, Zhu0000-0002-8968-7050
Additional Information:© 2018 Elsevier Ltd. Received 13 April 2018, Revised 15 November 2018, Accepted 16 November 2018, Available online 29 November 2018. Data accessibility: All data used are publicly available, sources are referenced in Sec. 3. Authors’ contributions: RG, DR, MKBL, BZ, JPK designed the study; ZL, RG collected the data; RG carried out the data analysis; RG, DR, MKBL, BZ validated the results; RG prepared the Figures; RG, DR, MKBL, JPK wrote and revised the manuscript. We declare we have no competing interests. Research Ethics: No experiments were carried out during this study and no prior ethical assessment was required. The research leading to these results has received funding from the European Community’s Seventh Framework Programme under Grant Agreement No. 308497 (Project RAMSES). Zhu Liu acknowledges support by the Green Talents Program held by the German Federal Ministry of Education and Research (BMBF). We thank M. Barthelemy, H. V. Ribeiro, and L. Costa for useful discussions. This work emerged from ideas discussed at the symposium Cities as Complex Systems (Hanover, July 13th-15th, 2016) which was generously funded by Volkswagen Foundation.
Funding AgencyGrant Number
European Research Council (ERC)308497
Bundesministerium für Bildung und Forschung (BMBF)UNSPECIFIED
Volkswagen FoundationUNSPECIFIED
Subject Keywords:Sustainable cities; Urban CO2 emissions; Urban scaling; Kaya Identity; Urban Kaya relation
Record Number:CaltechAUTHORS:20181129-142053737
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Official Citation:Ramana Gudipudi, Diego Rybski, Matthias K.B. Lüdeke, Bin Zhou, Zhu Liu, Jürgen P. Kropp, The efficient, the intensive, and the productive: Insights from urban Kaya scaling, Applied Energy, Volume 236, 2019, Pages 155-162, ISSN 0306-2619, (
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:91337
Deposited By: Tony Diaz
Deposited On:29 Nov 2018 22:28
Last Modified:29 Nov 2018 22:28

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