UN-Habitat’s Global Urban Lectures series began in 2014 and is now starting its sixth season. The lectures feature renowned experts discussing cutting-edge research and practical recommendations on advancing urban sustainability and the Sustainable Development Goals in cities. This season consists of 10 lectures that will be released every Tuesday until the end of August.

In the first lecture of the season, released on 23 June 2020, Nadine Ibrahim from the University of Waterloo describes the many ways in which emissions are accounted for and advocates for a standardized approach to calculating greenhouse gas emission inventories for cities in order to be able to compare numbers, and more importantly to learn from one another.


AUDIO: https://uni.unhabitat.org/wp-content/uploads/2018/08/Global-Urban-Lectures-Season-6-Nadine-Ibrahim.mp3


Issues which the lecture addresses

The lecture address different greenhouse gas emission inventories and the methodologies by which inventories for cities are calculated. The greenhouse gas emission numbers reported for cities may differ depending on what is included/excluded. The lecture compares a few inventories to highlight these issues. A standardized approach has been proposed that would enable cities to be able to compare numbers, and more importantly to learn from one another.

Short analysis of the above issues

Greenhouse gas emissions are calculated for different sectors of the city like buildings, transportation, waste, and water, and are categorized in a greenhouse gas emissions inventory based on direct, indirect and upstream/embodied emissions. The inventories are applied to a few cities to demonstrate these methodological differences.

Propositions for addressing the issue

- Principles of GHG accounting

- Emission Scopes (direct, indirect, upstream/lifecycle)

- GHG inventories and protocols

- Comparison of GHG inventories

- Case Study 1: New York City

- Case Study 2: Shanghai

- Case Study 3: Paris



Nadine is a Lecturer in the Department of Civil and Environmental Engineering and holds the Turkstra Chair in Urban Engineering. She comes from a cross-section of industry and academia in the areas of urban infrastructure, sustainable cities, and sustainable development. She holds a BASc (2000), MASc (2003), and PhD (2015) in Civil Engineering, and a Certificate of Preventive Engineering and Social Development, from the University of Toronto. Transcending the boundaries of Civil Engineering, she combines environmental engineering, and incorporates non-engineering fields including architecture, economics and governance. Previously, she was a post-doctoral fellow working on Engineering Education for Sustainable Cities in Africa, launching a “Sustainable Cities” course online, and piloting a Global Classroom.

Her research contributes to a wide spectrum of urban engineering fields and a broad range of global cities, megacities, and most recently megaregions, appearing in leading journals including Nature Climate Change, and the Proceedings of the National Academy of Sciences. She has been active in futures research on engineering education and co-authored

a book chapter “Educating Engineers for the Anthropocene” which appeared in the State of the World 2017: EarthED: Rethinking Education on a Changing Planet, published by the Worldwatch Institute in 2017. She currently chairs a special interest group on the Engineer of 2050 at the Canadian Engineering Education Association (CEEA).

For her role as the Turkstra Chair, her vision is to build a community of practice of leaders in municipal engineering and academics in urban research to offer leadership towards prospects for our future cities; and to develop urban sustainability literacy among students to motivate their technical specializations and empower them to traverse beyond their disciplines to create liveable futures. These efforts aim at increasing the role of civil engineers in urban government, and improving the career opportunities and authority of engineers in decision-making processes in cities.



Ibrahim, N., Sugar, L., Hoornweg, D., and Kennedy, C., 2012. “Greenhouse gas emissions from cities: comparison of

international inventory frameworks.” Local Environment, 17 (2), 223-241.


Sample of inventories:

Global Protocol for Community-Scale GHG Emission Inventory (GPC)

Local Government GHG Emissions Analysis Protocol – ICLEI

EC Covenant of Mayors (EC-CoM)

WB/UNEP/UNHABITAT International Standard


ISO 14064:2006

Greenhouse gas Regional Inventory Protocol – GRIP 

Bilan Carbone


CO2 Calculator

Project 2 Degrees


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See all Global Urban Lectures full packages (video, synopsis, biographies, additional reading material) here

The Global Urban Lecture series is an initiative by UNI – UN-Habitat’s partnership with universities worldwide