Experience

Publications

• Developing a multilayered indicator set for urban metabolism studies in megacities.

  Ecological Indicators

  Stewart, I., Kennedy, C., Ibrahim, N., Facchini, A., and Mele, R. 2014. Developing a multilayered indicator set for urban metabolism studies in megacities. Ecological Indicators, 47: 7-15

• Developing a multilayered indicator set for urban metabolism studies in megacities.

  Ecological Indicators

  Stewart, I., Kennedy, C., Ibrahim, N., Facchini, A., and Mele, R. 2014. Developing a multilayered indicator set for urban metabolism studies in megacities. Ecological Indicators, 47: 7-15

• Greenhouse gas emissions from cities: comparison of international inventory frameworks

  Local Environment: The International Journal of Justice and Sustainability

  Ibrahim, N., Sugar, L., Hoornweg, D., and Kennedy, C., 2012. Greenhouse gas emissions from cities: comparison of international inventory frameworks. Journal of Local Environment, 17 (2): 223-241. Credibly and consistently reporting greenhouse gas (GHG) emissions from cities and urban areas enables policy-makers and practitioners to contribute to addressing the challenge of climate change by meeting mitigation targets, and is critical to overall good municipal management. Good reporting allows for transparency, verification, and replication over time. This study provides an understanding of the GHG emissions inventory protocols and methodologies as they apply to cities. Though the inventories generally use common terminology, the differences in inventorying approaches are many, and the implications of the inventorying results at the city level are important to climate change policy and decision-makers. A compilation of GHG emissions inventory protocols is developed along with an analysis of their characteristics and inherent differences. Seven protocols are investigated: four are applied to Shanghai’s community emissions; four to New York City’s corporate emissions (i.e. those from municipal activities); and two to the reporting of Paris’ emissions, including upstream components. The results show a significant degree of variability among the protocols.

• Developing a multilayered indicator set for urban metabolism studies in megacities.

  Ecological Indicators

  Stewart, I., Kennedy, C., Ibrahim, N., Facchini, A., and Mele, R. 2014. Developing a multilayered indicator set for urban metabolism studies in megacities. Ecological Indicators, 47: 7-15

• Greenhouse gas emissions from cities: comparison of international inventory frameworks

  Local Environment: The International Journal of Justice and Sustainability

  Ibrahim, N., Sugar, L., Hoornweg, D., and Kennedy, C., 2012. Greenhouse gas emissions from cities: comparison of international inventory frameworks. Journal of Local Environment, 17 (2): 223-241. Credibly and consistently reporting greenhouse gas (GHG) emissions from cities and urban areas enables policy-makers and practitioners to contribute to addressing the challenge of climate change by meeting mitigation targets, and is critical to overall good municipal management. Good reporting allows for transparency, verification, and replication over time. This study provides an understanding of the GHG emissions inventory protocols and methodologies as they apply to cities. Though the inventories generally use common terminology, the differences in inventorying approaches are many, and the implications of the inventorying results at the city level are important to climate change policy and decision-makers. A compilation of GHG emissions inventory protocols is developed along with an analysis of their characteristics and inherent differences. Seven protocols are investigated: four are applied to Shanghai’s community emissions; four to New York City’s corporate emissions (i.e. those from municipal activities); and two to the reporting of Paris’ emissions, including upstream components. The results show a significant degree of variability among the protocols.

• Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet.

  Worldwatch Institute, Island Press

  Hoornweg, D., Ibrahim, N., Luo, C., 2017. Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet. Washington, Worldwatch Institute, Island Press, pp. 267-277.

• Developing a multilayered indicator set for urban metabolism studies in megacities.

  Ecological Indicators

  Stewart, I., Kennedy, C., Ibrahim, N., Facchini, A., and Mele, R. 2014. Developing a multilayered indicator set for urban metabolism studies in megacities. Ecological Indicators, 47: 7-15

• Greenhouse gas emissions from cities: comparison of international inventory frameworks

  Local Environment: The International Journal of Justice and Sustainability

  Ibrahim, N., Sugar, L., Hoornweg, D., and Kennedy, C., 2012. Greenhouse gas emissions from cities: comparison of international inventory frameworks. Journal of Local Environment, 17 (2): 223-241. Credibly and consistently reporting greenhouse gas (GHG) emissions from cities and urban areas enables policy-makers and practitioners to contribute to addressing the challenge of climate change by meeting mitigation targets, and is critical to overall good municipal management. Good reporting allows for transparency, verification, and replication over time. This study provides an understanding of the GHG emissions inventory protocols and methodologies as they apply to cities. Though the inventories generally use common terminology, the differences in inventorying approaches are many, and the implications of the inventorying results at the city level are important to climate change policy and decision-makers. A compilation of GHG emissions inventory protocols is developed along with an analysis of their characteristics and inherent differences. Seven protocols are investigated: four are applied to Shanghai’s community emissions; four to New York City’s corporate emissions (i.e. those from municipal activities); and two to the reporting of Paris’ emissions, including upstream components. The results show a significant degree of variability among the protocols.

• Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet.

  Worldwatch Institute, Island Press

  Hoornweg, D., Ibrahim, N., Luo, C., 2017. Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet. Washington, Worldwatch Institute, Island Press, pp. 267-277.

• Low carbon infrastructure strategies for cities.

  Nature Climate Change

  Kennedy, C., Ibrahim, N., and Hoornweg, D., 2014. Low carbon infrastructure strategies for cities. Nature Climate Change, 4 (5): 343-346. Reducing greenhouse gas emissions to avert potentially disastrous global climate change requires substantial redevelopment of infrastructure systems. Cities are recognized as key actors for leading such climate change mitigation efforts. We have studied the greenhousegas inventoriesand underlying characteristics of 22 global cities. These cities differ in terms of their climates, income, levels of industrial activity, urban form and existing carbon intensity of electricity supply. Here we show how these differences in city characteristics lead to wide variations in the type of strategies that can be used for reducing emissions. Cities experiencing greater than 1,500 heating degree days (below an 18 degrees C base), for example, will review building construction and retrofitting for cold climates. Electrification of infrastructure technologies is effective for cities where the carbon intensity of the grid is lower than 600 tCO2e/GWh; whereas transportation strategies will differ between low urban density (<6,000 persons/km2) and high urban density (>6,000 persons/km2) cities. As nation states negotiate targets and develop policies for reducing greenhouse gas emissions, attention to the specific characteristics of their cities will broaden and improve their suite of options. Beyond carbon pricing, markets and taxation, governments may develop policies and target spending towards low-carbon urban infrastructure.

• Developing a multilayered indicator set for urban metabolism studies in megacities.

  Ecological Indicators

  Stewart, I., Kennedy, C., Ibrahim, N., Facchini, A., and Mele, R. 2014. Developing a multilayered indicator set for urban metabolism studies in megacities. Ecological Indicators, 47: 7-15

• Greenhouse gas emissions from cities: comparison of international inventory frameworks

  Local Environment: The International Journal of Justice and Sustainability

  Ibrahim, N., Sugar, L., Hoornweg, D., and Kennedy, C., 2012. Greenhouse gas emissions from cities: comparison of international inventory frameworks. Journal of Local Environment, 17 (2): 223-241. Credibly and consistently reporting greenhouse gas (GHG) emissions from cities and urban areas enables policy-makers and practitioners to contribute to addressing the challenge of climate change by meeting mitigation targets, and is critical to overall good municipal management. Good reporting allows for transparency, verification, and replication over time. This study provides an understanding of the GHG emissions inventory protocols and methodologies as they apply to cities. Though the inventories generally use common terminology, the differences in inventorying approaches are many, and the implications of the inventorying results at the city level are important to climate change policy and decision-makers. A compilation of GHG emissions inventory protocols is developed along with an analysis of their characteristics and inherent differences. Seven protocols are investigated: four are applied to Shanghai’s community emissions; four to New York City’s corporate emissions (i.e. those from municipal activities); and two to the reporting of Paris’ emissions, including upstream components. The results show a significant degree of variability among the protocols.

• Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet.

  Worldwatch Institute, Island Press

  Hoornweg, D., Ibrahim, N., Luo, C., 2017. Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet. Washington, Worldwatch Institute, Island Press, pp. 267-277.

• Low carbon infrastructure strategies for cities.

  Nature Climate Change

  Kennedy, C., Ibrahim, N., and Hoornweg, D., 2014. Low carbon infrastructure strategies for cities. Nature Climate Change, 4 (5): 343-346. Reducing greenhouse gas emissions to avert potentially disastrous global climate change requires substantial redevelopment of infrastructure systems. Cities are recognized as key actors for leading such climate change mitigation efforts. We have studied the greenhousegas inventoriesand underlying characteristics of 22 global cities. These cities differ in terms of their climates, income, levels of industrial activity, urban form and existing carbon intensity of electricity supply. Here we show how these differences in city characteristics lead to wide variations in the type of strategies that can be used for reducing emissions. Cities experiencing greater than 1,500 heating degree days (below an 18 degrees C base), for example, will review building construction and retrofitting for cold climates. Electrification of infrastructure technologies is effective for cities where the carbon intensity of the grid is lower than 600 tCO2e/GWh; whereas transportation strategies will differ between low urban density (<6,000 persons/km2) and high urban density (>6,000 persons/km2) cities. As nation states negotiate targets and develop policies for reducing greenhouse gas emissions, attention to the specific characteristics of their cities will broaden and improve their suite of options. Beyond carbon pricing, markets and taxation, governments may develop policies and target spending towards low-carbon urban infrastructure.

• A Methodology for Constructing Marginal Abatement Cost Curves for Climate Action in Cities

  Energies

  As drivers of climate action, cities are taking measures to reduce greenhouse gas (GHG) emissions, which if left unabated pose a challenge to meeting long-term climate targets. The economics of climate action needs to be at the forefront of climate dialogue to prioritize investments among competing mitigation measures. A marginal abatement cost (MAC) curve is an effective visualization of climate action that initiates a technical and economic discussion of the cost-effectiveness and abatement potential of such actions among local leaders, policy makers, and climate experts. More commonly demonstrated for countries, MAC curves need to be developed for cities because of their heterogeneity, which vary in their urban activities, energy supply, infrastructure stock, and commuting patterns. The methodology for constructing bottom-up MAC curves for cities is presented for technologies that offer fuel switching and/or energy efficiencies, while considering technology lifetimes, city-specific electricity and fuel prices, and emission intensities. Resulting MAC curves are unique to every city, and chart the pathway towards low-carbon growth by prioritizing measures based on cost-effectiveness. A case study of Toronto’s climate targets demonstrates the prioritization of select technologies. Leveraging MAC curves to support climate programs enables cities to strategically invest in financing climate action and designing incentives.

• Developing a multilayered indicator set for urban metabolism studies in megacities.

  Ecological Indicators

  Stewart, I., Kennedy, C., Ibrahim, N., Facchini, A., and Mele, R. 2014. Developing a multilayered indicator set for urban metabolism studies in megacities. Ecological Indicators, 47: 7-15

• Greenhouse gas emissions from cities: comparison of international inventory frameworks

  Local Environment: The International Journal of Justice and Sustainability

  Ibrahim, N., Sugar, L., Hoornweg, D., and Kennedy, C., 2012. Greenhouse gas emissions from cities: comparison of international inventory frameworks. Journal of Local Environment, 17 (2): 223-241. Credibly and consistently reporting greenhouse gas (GHG) emissions from cities and urban areas enables policy-makers and practitioners to contribute to addressing the challenge of climate change by meeting mitigation targets, and is critical to overall good municipal management. Good reporting allows for transparency, verification, and replication over time. This study provides an understanding of the GHG emissions inventory protocols and methodologies as they apply to cities. Though the inventories generally use common terminology, the differences in inventorying approaches are many, and the implications of the inventorying results at the city level are important to climate change policy and decision-makers. A compilation of GHG emissions inventory protocols is developed along with an analysis of their characteristics and inherent differences. Seven protocols are investigated: four are applied to Shanghai’s community emissions; four to New York City’s corporate emissions (i.e. those from municipal activities); and two to the reporting of Paris’ emissions, including upstream components. The results show a significant degree of variability among the protocols.

• Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet.

  Worldwatch Institute, Island Press

  Hoornweg, D., Ibrahim, N., Luo, C., 2017. Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet. Washington, Worldwatch Institute, Island Press, pp. 267-277.

• Low carbon infrastructure strategies for cities.

  Nature Climate Change

  Kennedy, C., Ibrahim, N., and Hoornweg, D., 2014. Low carbon infrastructure strategies for cities. Nature Climate Change, 4 (5): 343-346. Reducing greenhouse gas emissions to avert potentially disastrous global climate change requires substantial redevelopment of infrastructure systems. Cities are recognized as key actors for leading such climate change mitigation efforts. We have studied the greenhousegas inventoriesand underlying characteristics of 22 global cities. These cities differ in terms of their climates, income, levels of industrial activity, urban form and existing carbon intensity of electricity supply. Here we show how these differences in city characteristics lead to wide variations in the type of strategies that can be used for reducing emissions. Cities experiencing greater than 1,500 heating degree days (below an 18 degrees C base), for example, will review building construction and retrofitting for cold climates. Electrification of infrastructure technologies is effective for cities where the carbon intensity of the grid is lower than 600 tCO2e/GWh; whereas transportation strategies will differ between low urban density (<6,000 persons/km2) and high urban density (>6,000 persons/km2) cities. As nation states negotiate targets and develop policies for reducing greenhouse gas emissions, attention to the specific characteristics of their cities will broaden and improve their suite of options. Beyond carbon pricing, markets and taxation, governments may develop policies and target spending towards low-carbon urban infrastructure.

• A Methodology for Constructing Marginal Abatement Cost Curves for Climate Action in Cities

  Energies

  As drivers of climate action, cities are taking measures to reduce greenhouse gas (GHG) emissions, which if left unabated pose a challenge to meeting long-term climate targets. The economics of climate action needs to be at the forefront of climate dialogue to prioritize investments among competing mitigation measures. A marginal abatement cost (MAC) curve is an effective visualization of climate action that initiates a technical and economic discussion of the cost-effectiveness and abatement potential of such actions among local leaders, policy makers, and climate experts. More commonly demonstrated for countries, MAC curves need to be developed for cities because of their heterogeneity, which vary in their urban activities, energy supply, infrastructure stock, and commuting patterns. The methodology for constructing bottom-up MAC curves for cities is presented for technologies that offer fuel switching and/or energy efficiencies, while considering technology lifetimes, city-specific electricity and fuel prices, and emission intensities. Resulting MAC curves are unique to every city, and chart the pathway towards low-carbon growth by prioritizing measures based on cost-effectiveness. A case study of Toronto’s climate targets demonstrates the prioritization of select technologies. Leveraging MAC curves to support climate programs enables cities to strategically invest in financing climate action and designing incentives.

• Decarbonization unique to cities

  Nature Climate Change

  Ibrahim, N., “Decarbonization unique to cities.” News and Views, Nature Climate Change, 7 (10): 690-691.

• Developing a multilayered indicator set for urban metabolism studies in megacities.

  Ecological Indicators

  Stewart, I., Kennedy, C., Ibrahim, N., Facchini, A., and Mele, R. 2014. Developing a multilayered indicator set for urban metabolism studies in megacities. Ecological Indicators, 47: 7-15

• Greenhouse gas emissions from cities: comparison of international inventory frameworks

  Local Environment: The International Journal of Justice and Sustainability

  Ibrahim, N., Sugar, L., Hoornweg, D., and Kennedy, C., 2012. Greenhouse gas emissions from cities: comparison of international inventory frameworks. Journal of Local Environment, 17 (2): 223-241. Credibly and consistently reporting greenhouse gas (GHG) emissions from cities and urban areas enables policy-makers and practitioners to contribute to addressing the challenge of climate change by meeting mitigation targets, and is critical to overall good municipal management. Good reporting allows for transparency, verification, and replication over time. This study provides an understanding of the GHG emissions inventory protocols and methodologies as they apply to cities. Though the inventories generally use common terminology, the differences in inventorying approaches are many, and the implications of the inventorying results at the city level are important to climate change policy and decision-makers. A compilation of GHG emissions inventory protocols is developed along with an analysis of their characteristics and inherent differences. Seven protocols are investigated: four are applied to Shanghai’s community emissions; four to New York City’s corporate emissions (i.e. those from municipal activities); and two to the reporting of Paris’ emissions, including upstream components. The results show a significant degree of variability among the protocols.

• Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet.

  Worldwatch Institute, Island Press

  Hoornweg, D., Ibrahim, N., Luo, C., 2017. Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet. Washington, Worldwatch Institute, Island Press, pp. 267-277.

• Low carbon infrastructure strategies for cities.

  Nature Climate Change

  Kennedy, C., Ibrahim, N., and Hoornweg, D., 2014. Low carbon infrastructure strategies for cities. Nature Climate Change, 4 (5): 343-346. Reducing greenhouse gas emissions to avert potentially disastrous global climate change requires substantial redevelopment of infrastructure systems. Cities are recognized as key actors for leading such climate change mitigation efforts. We have studied the greenhousegas inventoriesand underlying characteristics of 22 global cities. These cities differ in terms of their climates, income, levels of industrial activity, urban form and existing carbon intensity of electricity supply. Here we show how these differences in city characteristics lead to wide variations in the type of strategies that can be used for reducing emissions. Cities experiencing greater than 1,500 heating degree days (below an 18 degrees C base), for example, will review building construction and retrofitting for cold climates. Electrification of infrastructure technologies is effective for cities where the carbon intensity of the grid is lower than 600 tCO2e/GWh; whereas transportation strategies will differ between low urban density (<6,000 persons/km2) and high urban density (>6,000 persons/km2) cities. As nation states negotiate targets and develop policies for reducing greenhouse gas emissions, attention to the specific characteristics of their cities will broaden and improve their suite of options. Beyond carbon pricing, markets and taxation, governments may develop policies and target spending towards low-carbon urban infrastructure.

• A Methodology for Constructing Marginal Abatement Cost Curves for Climate Action in Cities

  Energies

  As drivers of climate action, cities are taking measures to reduce greenhouse gas (GHG) emissions, which if left unabated pose a challenge to meeting long-term climate targets. The economics of climate action needs to be at the forefront of climate dialogue to prioritize investments among competing mitigation measures. A marginal abatement cost (MAC) curve is an effective visualization of climate action that initiates a technical and economic discussion of the cost-effectiveness and abatement potential of such actions among local leaders, policy makers, and climate experts. More commonly demonstrated for countries, MAC curves need to be developed for cities because of their heterogeneity, which vary in their urban activities, energy supply, infrastructure stock, and commuting patterns. The methodology for constructing bottom-up MAC curves for cities is presented for technologies that offer fuel switching and/or energy efficiencies, while considering technology lifetimes, city-specific electricity and fuel prices, and emission intensities. Resulting MAC curves are unique to every city, and chart the pathway towards low-carbon growth by prioritizing measures based on cost-effectiveness. A case study of Toronto’s climate targets demonstrates the prioritization of select technologies. Leveraging MAC curves to support climate programs enables cities to strategically invest in financing climate action and designing incentives.

• Decarbonization unique to cities

  Nature Climate Change

  Ibrahim, N., “Decarbonization unique to cities.” News and Views, Nature Climate Change, 7 (10): 690-691.

• An urban metabolism survey design for megacities.

  Enel Foundation. ISSN 2282-7188

  Kennedy, C., Ibrahim, N., Stewart, I., Facchini, A., and Mele, R., 2014. An urban metabolism survey design for megacities. Working Paper 2/2014, Megacities: Comparative analysis of urban macrosystems. Enel Foundation. ISSN 2282-7188

• Developing a multilayered indicator set for urban metabolism studies in megacities.

  Ecological Indicators

  Stewart, I., Kennedy, C., Ibrahim, N., Facchini, A., and Mele, R. 2014. Developing a multilayered indicator set for urban metabolism studies in megacities. Ecological Indicators, 47: 7-15

• Greenhouse gas emissions from cities: comparison of international inventory frameworks

  Local Environment: The International Journal of Justice and Sustainability

  Ibrahim, N., Sugar, L., Hoornweg, D., and Kennedy, C., 2012. Greenhouse gas emissions from cities: comparison of international inventory frameworks. Journal of Local Environment, 17 (2): 223-241. Credibly and consistently reporting greenhouse gas (GHG) emissions from cities and urban areas enables policy-makers and practitioners to contribute to addressing the challenge of climate change by meeting mitigation targets, and is critical to overall good municipal management. Good reporting allows for transparency, verification, and replication over time. This study provides an understanding of the GHG emissions inventory protocols and methodologies as they apply to cities. Though the inventories generally use common terminology, the differences in inventorying approaches are many, and the implications of the inventorying results at the city level are important to climate change policy and decision-makers. A compilation of GHG emissions inventory protocols is developed along with an analysis of their characteristics and inherent differences. Seven protocols are investigated: four are applied to Shanghai’s community emissions; four to New York City’s corporate emissions (i.e. those from municipal activities); and two to the reporting of Paris’ emissions, including upstream components. The results show a significant degree of variability among the protocols.

• Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet.

  Worldwatch Institute, Island Press

  Hoornweg, D., Ibrahim, N., Luo, C., 2017. Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet. Washington, Worldwatch Institute, Island Press, pp. 267-277.

• Low carbon infrastructure strategies for cities.

  Nature Climate Change

  Kennedy, C., Ibrahim, N., and Hoornweg, D., 2014. Low carbon infrastructure strategies for cities. Nature Climate Change, 4 (5): 343-346. Reducing greenhouse gas emissions to avert potentially disastrous global climate change requires substantial redevelopment of infrastructure systems. Cities are recognized as key actors for leading such climate change mitigation efforts. We have studied the greenhousegas inventoriesand underlying characteristics of 22 global cities. These cities differ in terms of their climates, income, levels of industrial activity, urban form and existing carbon intensity of electricity supply. Here we show how these differences in city characteristics lead to wide variations in the type of strategies that can be used for reducing emissions. Cities experiencing greater than 1,500 heating degree days (below an 18 degrees C base), for example, will review building construction and retrofitting for cold climates. Electrification of infrastructure technologies is effective for cities where the carbon intensity of the grid is lower than 600 tCO2e/GWh; whereas transportation strategies will differ between low urban density (<6,000 persons/km2) and high urban density (>6,000 persons/km2) cities. As nation states negotiate targets and develop policies for reducing greenhouse gas emissions, attention to the specific characteristics of their cities will broaden and improve their suite of options. Beyond carbon pricing, markets and taxation, governments may develop policies and target spending towards low-carbon urban infrastructure.

• A Methodology for Constructing Marginal Abatement Cost Curves for Climate Action in Cities

  Energies

  As drivers of climate action, cities are taking measures to reduce greenhouse gas (GHG) emissions, which if left unabated pose a challenge to meeting long-term climate targets. The economics of climate action needs to be at the forefront of climate dialogue to prioritize investments among competing mitigation measures. A marginal abatement cost (MAC) curve is an effective visualization of climate action that initiates a technical and economic discussion of the cost-effectiveness and abatement potential of such actions among local leaders, policy makers, and climate experts. More commonly demonstrated for countries, MAC curves need to be developed for cities because of their heterogeneity, which vary in their urban activities, energy supply, infrastructure stock, and commuting patterns. The methodology for constructing bottom-up MAC curves for cities is presented for technologies that offer fuel switching and/or energy efficiencies, while considering technology lifetimes, city-specific electricity and fuel prices, and emission intensities. Resulting MAC curves are unique to every city, and chart the pathway towards low-carbon growth by prioritizing measures based on cost-effectiveness. A case study of Toronto’s climate targets demonstrates the prioritization of select technologies. Leveraging MAC curves to support climate programs enables cities to strategically invest in financing climate action and designing incentives.

• Decarbonization unique to cities

  Nature Climate Change

  Ibrahim, N., “Decarbonization unique to cities.” News and Views, Nature Climate Change, 7 (10): 690-691.

• An urban metabolism survey design for megacities.

  Enel Foundation. ISSN 2282-7188

  Kennedy, C., Ibrahim, N., Stewart, I., Facchini, A., and Mele, R., 2014. An urban metabolism survey design for megacities. Working Paper 2/2014, Megacities: Comparative analysis of urban macrosystems. Enel Foundation. ISSN 2282-7188

• Energy and material flows of megacities

  Proceedings of the National Academy of Sciences

  Understanding the drivers of energy and material flows of cities is important for addressing global environmental challenges. Accessing, sharing, and managing energy and material resources is particularly critical for megacities, which face enormous social stresses because of their sheer size and complexity. Here we quantify the energy and material flows through the world’s 27 megacities with populations greater than 10 million people as of 2010. Collectively the resource flows through megacities are largely consistent with scaling laws established in the emerging science of cities. Correlations are established for electricity consumption, heating and industrial fuel use, ground transportation energy use, water consumption, waste generation, and steel production in terms of heating-degree-days, urban form, economic activity, and population growth. The results help identify megacities exhibiting high and low levels of consumption and those making efficient use of resources. The correlation between per capita electricity use and urbanized area per capita is shown to be a consequence of gross building floor area per capita, which is found to increase for lower-density cities. Many of the megacities are growing rapidly in population but are growing even faster in terms of gross domestic product (GDP) and energy use. In the decade from 2001-2011, electricity use and ground transportation fuel use in megacities grew at approximately half the rate of GDP growth.

• Developing a multilayered indicator set for urban metabolism studies in megacities.

  Ecological Indicators

  Stewart, I., Kennedy, C., Ibrahim, N., Facchini, A., and Mele, R. 2014. Developing a multilayered indicator set for urban metabolism studies in megacities. Ecological Indicators, 47: 7-15

• Greenhouse gas emissions from cities: comparison of international inventory frameworks

  Local Environment: The International Journal of Justice and Sustainability

  Ibrahim, N., Sugar, L., Hoornweg, D., and Kennedy, C., 2012. Greenhouse gas emissions from cities: comparison of international inventory frameworks. Journal of Local Environment, 17 (2): 223-241. Credibly and consistently reporting greenhouse gas (GHG) emissions from cities and urban areas enables policy-makers and practitioners to contribute to addressing the challenge of climate change by meeting mitigation targets, and is critical to overall good municipal management. Good reporting allows for transparency, verification, and replication over time. This study provides an understanding of the GHG emissions inventory protocols and methodologies as they apply to cities. Though the inventories generally use common terminology, the differences in inventorying approaches are many, and the implications of the inventorying results at the city level are important to climate change policy and decision-makers. A compilation of GHG emissions inventory protocols is developed along with an analysis of their characteristics and inherent differences. Seven protocols are investigated: four are applied to Shanghai’s community emissions; four to New York City’s corporate emissions (i.e. those from municipal activities); and two to the reporting of Paris’ emissions, including upstream components. The results show a significant degree of variability among the protocols.

• Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet.

  Worldwatch Institute, Island Press

  Hoornweg, D., Ibrahim, N., Luo, C., 2017. Chapter 22. Educating Engineers for the Anthropocene, In: Assadourian, E. and Mastny, L. eds., State of the World 2017: EarthED: Rethinking Education on a Changing Planet. Washington, Worldwatch Institute, Island Press, pp. 267-277.

• Low carbon infrastructure strategies for cities.

  Nature Climate Change

  Kennedy, C., Ibrahim, N., and Hoornweg, D., 2014. Low carbon infrastructure strategies for cities. Nature Climate Change, 4 (5): 343-346. Reducing greenhouse gas emissions to avert potentially disastrous global climate change requires substantial redevelopment of infrastructure systems. Cities are recognized as key actors for leading such climate change mitigation efforts. We have studied the greenhousegas inventoriesand underlying characteristics of 22 global cities. These cities differ in terms of their climates, income, levels of industrial activity, urban form and existing carbon intensity of electricity supply. Here we show how these differences in city characteristics lead to wide variations in the type of strategies that can be used for reducing emissions. Cities experiencing greater than 1,500 heating degree days (below an 18 degrees C base), for example, will review building construction and retrofitting for cold climates. Electrification of infrastructure technologies is effective for cities where the carbon intensity of the grid is lower than 600 tCO2e/GWh; whereas transportation strategies will differ between low urban density (<6,000 persons/km2) and high urban density (>6,000 persons/km2) cities. As nation states negotiate targets and develop policies for reducing greenhouse gas emissions, attention to the specific characteristics of their cities will broaden and improve their suite of options. Beyond carbon pricing, markets and taxation, governments may develop policies and target spending towards low-carbon urban infrastructure.

• A Methodology for Constructing Marginal Abatement Cost Curves for Climate Action in Cities

  Energies

  As drivers of climate action, cities are taking measures to reduce greenhouse gas (GHG) emissions, which if left unabated pose a challenge to meeting long-term climate targets. The economics of climate action needs to be at the forefront of climate dialogue to prioritize investments among competing mitigation measures. A marginal abatement cost (MAC) curve is an effective visualization of climate action that initiates a technical and economic discussion of the cost-effectiveness and abatement potential of such actions among local leaders, policy makers, and climate experts. More commonly demonstrated for countries, MAC curves need to be developed for cities because of their heterogeneity, which vary in their urban activities, energy supply, infrastructure stock, and commuting patterns. The methodology for constructing bottom-up MAC curves for cities is presented for technologies that offer fuel switching and/or energy efficiencies, while considering technology lifetimes, city-specific electricity and fuel prices, and emission intensities. Resulting MAC curves are unique to every city, and chart the pathway towards low-carbon growth by prioritizing measures based on cost-effectiveness. A case study of Toronto’s climate targets demonstrates the prioritization of select technologies. Leveraging MAC curves to support climate programs enables cities to strategically invest in financing climate action and designing incentives.

• Decarbonization unique to cities

  Nature Climate Change

  Ibrahim, N., “Decarbonization unique to cities.” News and Views, Nature Climate Change, 7 (10): 690-691.

• An urban metabolism survey design for megacities.

  Enel Foundation. ISSN 2282-7188

  Kennedy, C., Ibrahim, N., Stewart, I., Facchini, A., and Mele, R., 2014. An urban metabolism survey design for megacities. Working Paper 2/2014, Megacities: Comparative analysis of urban macrosystems. Enel Foundation. ISSN 2282-7188

• Energy and material flows of megacities

  Proceedings of the National Academy of Sciences

  Understanding the drivers of energy and material flows of cities is important for addressing global environmental challenges. Accessing, sharing, and managing energy and material resources is particularly critical for megacities, which face enormous social stresses because of their sheer size and complexity. Here we quantify the energy and material flows through the world’s 27 megacities with populations greater than 10 million people as of 2010. Collectively the resource flows through megacities are largely consistent with scaling laws established in the emerging science of cities. Correlations are established for electricity consumption, heating and industrial fuel use, ground transportation energy use, water consumption, waste generation, and steel production in terms of heating-degree-days, urban form, economic activity, and population growth. The results help identify megacities exhibiting high and low levels of consumption and those making efficient use of resources. The correlation between per capita electricity use and urbanized area per capita is shown to be a consequence of gross building floor area per capita, which is found to increase for lower-density cities. Many of the megacities are growing rapidly in population but are growing even faster in terms of gross domestic product (GDP) and energy use. In the decade from 2001-2011, electricity use and ground transportation fuel use in megacities grew at approximately half the rate of GDP growth.

• GEF Country Portfolio Evaluation: Egypt (1991–2008)

  Global Environment Facility - Evaluation Office