Climate Change Mitigation In Cities Research Articles

Managing climate change mitigation in cities: a European experience

Managing climate change mitigation in cities: a European experience

Institutional pathways to municipal energy companies in the UK: Realising co-benefits to mitigate climate change in cities

Municipalities in the UK are increasingly engaging in local management of one or more parts of the energy system. The municipal energy companies set up to manage this engagement have the potential to contribute to a low-carbon transition through acceleration of low-carbon energy technology roll-out and demand management. However, municipal energy companies face many constraints that limit their growth in number and scale and restrict their potential to contribute to climate change mitigation. This paper aims to develop a better understanding of why and how municipal energy companies form to help to identify how policy and regulation could better support their proliferation and their contribution to climate change mitigation. We conducted a longitudinal analysis (from 2013 to 2017) of five UK cities’ attempts to develop new institutional arrangements to engage in the national energy system and contribute to climate change mitigation. We found that the fundamental purpose of municipal energy companies was different to those of the private sector; using energy to deliver essential services and place-specific outcomes, rather than aiming to deliver energy at least cost. The scope of engagement was dependent on a city’s unique characteristics and factors driving decisions. We found that there was no blueprint for a municipal energy company, rather the final form was shaped by a city’s unique characteristics and decision drivers and emerged from a process of experimentation and learning. This ‘pathway’ towards a municipal energy company is also heavily influenced by the changing policy context, meaning that studying the evolution of municipal energy companies over time is very important. Specific changes in UK policy have significantly reduced the potential of municipal energy companies to contribute to carbon emissions reduction. We propose a framework of characteristics, decision drivers and pathways to better understand the evolution of municipal energy companies and to support the identification of policy and regulation that could enable their proliferation. We illustrate the application of this framework to maximise the contribution of municipal energy companies to climate change mitigation in cities. We identified a need for policy to recognise and enable different institutional drivers (including climate change) and institutional forms and encourage experimentation. Furthermore, new approaches to accounting and valuation are needed that capture social and environmental outcomes and outcomes that occur in the long-term.

Ecological Footprint assessment for targeting climate change mitigation in cities: A case study of 15 Canadian cities according to census metropolitan areas

As the world moves towards a carbon-free future, cities have been identified as key hubs for change. They have the greatest ability to quickly develop more efficient systems and implement climate change mitigation policies. Moreover, cities will become the destination of a population migration as humanity grows globally to a population of 11 billion. In this case study, we show that the applicability of the Ecological Footprint, an overarching outcome measure of resource consumption, for targeting climate change mitigation in cities. We focus on the carbon Footprint subcomponent of the Ecological Footprint, and further translate and disaggregate the carbon Footprint into detailed classification of individual consumption according to purpose (COICOP) and analyze the Footprint of consumption associated with each of these categories for 15 Canadian cities according to census metropolitan area (CMA), from each province. The Ecological Footprint of CMAs was calculated from the consumption land use matrix (CLUM) of Canada, by scaling results according to the annual national survey of household spending from 2010 to 2015. The expenditure in electricity was also scaled with the carbon intensity factor. Our findings indicate that the carbon Footprint remains the largest contributor of the Ecological Footprint of CMAs. The carbon Footprint associated with housing varied significantly with the source of electricity production. CMAs relying on renewable energy sources have a substantially lower carbon Footprint than those relying on fossil fuel energy. The carbon Footprint associated with the operation of personal transportation was the second largest among all consumption categories. Financial services is the largest share of the carbon Footprint from service consumption. Clothing consumption caused most of the goods’ carbon Footprint. A better understanding of urban planning of Canadian CMAs and promoting local consumption will improve carbon mitigation and long-term sustainability.

Techniques and criteria for sustainable urban stormwater management. The case study of Valdebebas (Madrid, Spain)

Improving the management of the urban water cycle can reduce greenhouse gas emissions and contribute to climate change mitigation in cities. Stormwater in urban areas has traditionally been collected and conveyed to sewage treatment plants, a practice that has continued with the need to manage increased superficial flow. This paper presents the Low Impact Development (LID) measures to improve water management in the new urban development of Valdebebas in Madrid, and the associated benefits. Stormwater was considered a sub cycle; by shortening the water cycle the local use of rainwater was achieved while reducing energy costs and greenhouse gas emissions for off-site treatment.The article analyses the urban water cycle from a preventive approach. It considers how urban design features such as topography and pavement selection were used to convey surface water from impermeable areas to permeable ones (vegetated or permeable pavements) and the infiltration of water into engineered soil, reducing the need for off-site conveyance infrastructure, and the amount of water discharged into municipal treatment installations. Moreover, the captured water increases soil water content available for plants and trees which play an important role in absorbing CO2. Water exceeding soil capacity is collected in the subsurface Sustainable Drainage system (SuDS), including infiltration boxes where water is temporarily stored before moving through the soil toward ground water reserves.This paper describes the approaches and criteria used to design a large scale SuDS infrastructure in the district of Valdebebas, in northeastern Madrid (Spain), and analyses its performance, followed by a comparison with the predictions under three climate change scenarios, which consider not only the variation in peak flows and runoff, but also the reduction in GHG emissions. Additionally, it presents a sensitivity analysis for the main variables in the design of SuDS, and a multicriteria analysis, to compare the different drainage systems.

Urban Green Spaces Enhance Climate Change Mitigation in Cities of the Global South: The Case of Kumasi, Ghana

Urban green spaces (UGS) contribute to mitigate climate change impacts via carbon sequestration and offer several co-benefits in cities. This contribution, however, is omitted in most national and regional carbon stock estimates, and related literature in the global south is – at best – fragmentary. Therefore, this paper quantifies and maps the distribution of UGS above and below-ground carbon pools in Kumasi, Ghana.Vegetation carbon stocks were estimated using allometric equations for trees and destructive sampling for crops and other herbaceous plants. Soil organic carbon (SOC) was determined to a depth of 60cm. Satellite imagery and GIS were used to map and extrapolate carbon stock estimates to a citywide scale.In the metropolitan area of Kumasi, a total of 3,758 Gg of carbon is stored above (vegetation) and below-ground (roots and soil). On average, 239 Mg C ha-1 is stored in trees and 81 Mg C ha-1 in the soil. Crops and herbs hold <1% of the total stock. There is no correlation between SOC and tree C stocks (r=0.1073, p=0.2982). Vegetation carbon stocks differ among UGS (p=0.0071). The highest SOC stocks are in cemeteries (111 Mg C ha-1) and home gardens (105 Mg C ha-1) while the lowest (46 Mg C ha-1) occur under natural forest relics. No significant differences were observed in soils under all other UGS types. SOC stock dynamics within and between depths differ among UGS types (p<0.0001).Above and below-ground carbon stocks in Kumasi are quite enormous and sensitive to the UGS type. UGS should be accounted for in urban planning and included in national and regional carbon budgets. These findings complement the global carbon budget datasets and are relevant to urban climate change policy.

From landfilling to waste incineration: Implications on GHG emissions of different actors

Concern over climate change has increased the efforts for climate change mitigation in cities and companies. At the same time, the EU policies promote material and energy recovery from waste, and the production of energy from renewable sources. In the energy system, the replacement of another energy production plant with a waste to energy plant (WTE) may either increase or decrease the total emissions. Cities and companies calculate their greenhouse gas emissions or carbon footprints using various calculation protocols, and a change from landfilling to waste incineration affects the emissions of these actors in various ways depending on the system boundaries. In this contribution, impact of a change from landfilling to WTE on the emissions of different actors is calculated for the case in which WTE replaces separate production of district heat (DH) by natural gas and electricity by coal. In the case of a waste management company, emissions decreased from about 51kt CO2-eq in 2009 (before introduction of the WTE) to −33kt CO2-eq in 2030. Emissions of DH company decreased by 40%, whereas at the city-level the combined emissions of waste management and district heat consumption decreased 60% between 2009 and 2030. The significance of the energy source to be replaced by energy from WTE on the potential GHG emission reductions was also calculated for different options. The emissions of electricity and district heat produced by WTE were 35–60% smaller than emissions from separate production of district heat by oil or natural gas and production of electricity by natural gas or coal. When electricity and DH produced by the WTE replaced those produced by alternative CHP plants, the impact varied from increase of emissions by 50% to decrease of emissions by 40% depending on the fuel of the CHP plant and electricity source used to cover the smaller electricity generation by the WTE. However, in all the cases, when the avoided emissions from landfilling were taken into account, the emissions of WTE were smaller than those of alternative waste management and energy generation options over time.