Ira Daniel Posen

• PhD, Engineering & Public Policy, and Civil & Environmental Engineering
• Professor (Assistant) at University of Toronto

The narrow scope of the U.S. renewable fuel standard (RFS2) is a missed opportunity to spur a wider range of biomass use. This is especially relevant as RFS2 targets are being missed due to demand-side limitations for ethanol consumption. This paper examines the greenhouse gas (GHG) implications of a more flexible policy based on RFS2, which includ...

Interest in bio-based products has been motivated, in part, by the claim that these products have lower life cycle greenhouse gas (GHG) emissions than their fossil counterparts. This study investigates GHG emissions from U.S. production of three important bio-based polymer families: polylactic acid (PLA), polyhydroxybutyrate (PHB) and bioethylene-b...

This work investigates, through semi-structured interviews, the prospects for rapid transitions towards low-carbon civil infrastructure systems. Rapid greenhouse gas (GHG) mitigation is critical to facilitate the near-term (i.e. within five years) reductions needed to limit global temperature rise to 2 °C. In addition, ongoing delays in climate act...

The past decade has seen a surge in public and private interest in the application of life cycle assessment (LCA), further accelerated by the emergence of new policies and disclosure practices explicitly mandating LCA. Simultaneously, the magnitude and diversity of stakeholder groups affected by LCA and LCA-based decision making have expanded rapid...

Electrifying light-duty vehicle fleets is essential to decarbonize road transport, however its efficacy relies on policies targeting country-specific challenges and opportunities. We model and compare fleet-level life cycle GHG emissions for different grid scenarios and battery electric vehicle deployment timelines respectively in the US, China, an...

We present a dynamic perspective to quantify the air quality–related health impacts of the electrification of light-duty vehicles in the United States between 2022 and 2050. Using a fleet turnover model and future electricity generation mix scenarios, we compare ambitious vehicle electrification to fleet renewal relying on newer internal combustion...

Globally, sales of battery electric vehicles (BEVs) are surpassing records every year, and their growing charging needs will ultimately reshape power infrastructure planning practices. While studies have analyzed the impact of light-duty BEVs on the electricity sector, they have overlooked the prospective evolution in charging profiles. We develope...

Pervasive plug-in fast chargers and/or electrified roadways (eRoads) might address the limited range, long recharging times, and reliance on greenhouse gas (GHG)-intensive, costly, and heavy batteries associated with electrifying long-haul heavy-duty trucks (HDTs). While these large-scale interventions shift environmental and cost burdens onto infr...

This paper examines the tension between needing to build more infrastructure and housing and simultaneously reduce greenhouse gas emissions (GHG) to avoid the most catastrophic impacts of climate change. This study uses an Environmentally Extended Input-Output approach to conduct a high-resolution top-down analysis of Canada’s national construction...

International Civil Aviation Organization member states need to develop national strategies for sustainable aviation fuel (SAF) production to reduce greenhouse gas emissions from aviation. In this work, we developed a framework to estimate the national SAF potential and applied it to a case study for canola SAF in Canada. Specifically, we answered...

The UK zero-emissions vehicle (ZEV) mandate aims for battery electric vehicles (BEVs) to account for 100% of new sales by 2035. This study presents a fleet-scale life cycle assessment model of UK light duty vehicles through 2050, integrating a dynamic material flow analysis to evaluate the implications on critical battery materials. Rapid uptake of...

With light duty vehicles (LDVs) responsible for 17% of annual US greenhouse gas (GHG) emissions, integrating emerging GHG-reducing technologies into the fleet is essential. However, the slow rate of vehicle turnover presents a significant barrier to the market penetration of new technologies, with adoption delayed by the low number of vehicles need...

Despite international efforts to increase the adoption of alternative fuel vehicles, global gasoline internal combustion engine vehicles (ICEV-Gs) sales are projected to remain strong for the coming decades, with electric vehicles (EV) sales remaining well below 50% under International Energy Agency projections for 2030. The current study analyzes...

A sustainable low-carbon transition via electric vehicles will require a comprehensive understanding of lithium-ion batteries’ global supply chain environmental impacts. Here, we analyze the cradle-to-gate energy use and greenhouse gas emissions of current and future nickel-manganese-cobalt and lithium-iron-phosphate battery technologies. We consid...

Lifestyle choices and consumption play a large role in contributing to per capita greenhouse gas emissions. Certain activities, like fossil fuel ground transportation, long-haul flights, diets with animal products and residential heating and cooling contribute significantly to per capita emissions. There is uncertainty around whether literacy about...

EVS HAVE FINALLY COME OF AGE. The total cost of purchasing and driving one–the cost of ownership–has fallen nearly to parity with a typical gasoline-fueled car. Scientists and engineers have extended the range of EVs by cramming ever more energy into their batteries, and vehicle charging networks have expanded in many countries. In the United State...

Vehicle electrification is one of the most promising climate change mitigation strategies for light-duty vehicles (LDVs). But vehicle electrification shifts the greenhouse gas (GHG) emission profiles of conventional LDVs with emissions moving upstream from vehicle use to electricity generation and vehicle production. Electric vehicle (EV) deploymen...

Cold weather operability is sometimes a limiting factor in the use of biodiesel blends for transportation. Regional temperature variability can therefore influence biodiesel adoption, with potential economic and environmental implications. This study assesses present and future biodiesel cold weather operability limits in North America according to...

Automated vehicles can facilitate vehicle sharing within and between households, thus decreasing ownership rates, albeit increasing miles travelled. While electrification can achieve deep reductions in transportation-related greenhouse gas emissions, shared automated electric vehicles will have different charging needs considering their higher mile...

Technological progress is an effective way to improve fuel economy in vehicles. Using a rich model-level dataset of all new passenger cars in China from 2010 to 2019, this paper estimates progress in fuel economy after controlling for increases in vehicle performance. Considering the unique structure of the automobile industry in China, we explore...

Addressing the “slum challenge” is essential for urban sustainability and the capacity of cities to provide a minimum quality of life to their residents. To present policy-makers with data to inform strategies to improve the lives of marginalized urban residents, this paper reviews quantitative indicators on slum infrastructure, and demonstrates an...

Africa is set to become a key contributor to global energy demand. Urban growth and the energy use of city residents will drive much of the region's changing energy picture. However, few studies have assessed residential energy use among African cities, and the heterogeneity in energy use at the sub-city scale. We use the case of Dar es Salaam, whi...

Climate change mitigation strategies are often technology-oriented, and electric vehicles (EVs) are a good example of something believed to be a silver bullet. Here we show that current US policies are insufficient to remain within a sectoral CO2 emission budget for light-duty vehicles, consistent with preventing more than 2 °C global warming, crea...

Electrification of urban transportation systems is an important path towards achieving low carbon transportation and meeting climate commitments. Despite zero on-road greenhouse gas emissions, the upstream emissions from electricity generation cannot be ignored. In this study, a heuristic algorithm was designed to optimize regional electric vehicle...

Replacing conventional gasoline with mid-level ethanol blends (15–30% ethanol by volume) can reduce fossil fuel use and greenhouse gas (GHG) emissions but require vehicle compatibility. This study quantifies the changes in fuel volumes and well-to-wheel (WTW) GHG emissions associated with potential mid-level ethanol blend deployment in Canada's lig...

Green policies currently incentivize concrete producers to replace portland cement with industrial by-products to reduce their greenhouse gas (GHG) emissions. However, policies are based on attributional life cycle assessments (LCAs) that do not account for market constraints and consider by-products either available burden-free to the user (cut-of...

Environmental life cycle assessment (LCA) is increasingly being used to evaluate infrastructure products and to inform their funding, design and construction. As such, recognition of study limitations and consideration of uncertainty are needed; however, most infrastructure LCAs still report deterministic values. Compared to other LCA subfields, in...

The refurbished Don Valley Brick Works’ Kiln Building, in Toronto, Canada, now the TD Future Cities Centre, is designed to have net zero carbon emissions. This is to be achieved through the reuse of existing materials and structures, selection of lower-carbon materials purchased from local sources, installation of renewable energy systems, natural...

Aluminum is one of the most used metals of modern civilization, but its production is responsible for multiple adverse environmental impacts mostly due to aluminum smelting and alumina refining. Previous life cycle assessments (LCAs) have aggregated alumina refining into a single global process even though refining processes are highly spatially di...

This paper presents three scenarios of urban growth, energy use and greenhouse gas (GHG) emissions in Dar es Salaam using narratives that are consistent with the Shared Socio-Economic Pathways (SSPs). We estimate residential energy demand and GHG emissions from 2015 to 2050 for household activities (including upstream electricity generation) and pa...

Commercial vehicle movements have a large effect on traffic-related air pollution in metropolitan areas. In the Greater Toronto and Hamilton Area (GTHA), commercial vehicles include large and medium diesel trucks as well as light-duty gasoline-fuelled trucks. In this study, the emissions of various air pollutants associated with diesel commercial v...

Life cycle assessment (LCA) analysts are increasingly being asked to conduct life cycle‐based systems level analysis at the earliest stages of technology development. While early assessments provide the greatest opportunity to influence design and ultimately environmental performance, it is the stage with the least available data, greatest uncertai...

Electric vehicles (EVs) are one of the most important paths for achieving low carbon transportation. Despite zero on-road greenhouse gas (GHG) emissions, their upstream emissions from electricity generation cannot be ignored. Taking GHG minimization as the objective, fulfilling regional auto travel demand at the same time, this study designs an opt...

A key motivation behind the development and adoption of industrial biotechnology is the reduction of negative environmental impacts. However, accurately assessing these impacts remains a formidable task. Environmental impacts of industrial biotechnology may be significant across a number of categories that include, but may not be limited to, nonren...

To estimate greenhouse gas (GHG) emission reductions of electric vehicles (EVs) deployment, it is important to account for emissions from electricity generation. Since such emissions change according to temporal patterns of electricity generation and EV charging, this study operationalizes the concept of marginal emission factors (MEFs) and uses pe...

Substituting conventional materials with lightweight materials is an effective way to reduce the life cycle greenhouse gas (GHG) emissions from light-duty vehicles. However, estimated GHG emission reductions of lightweighting depend on multiple factors including the vehicle powertrain technology and efficiency, lightweight material employed, and en...

Fuel economy standards, driver behavior, and biofuel mandates, are driving a decline in the Gasoline-to-Diesel ratio (G:D) in U.S. refineries. This paper investigates the GHG implications associated with two methods available to shift refinery output: 1) refinery operational changes and 2) input crude slate variation. This analysis uses an open-sou...

ABTRACT - Preparing a literate public to critically evaluate issues related to climate change, energy and the environment is an important pillar towards more sustainable societies. The Summer Center for Climate, Energy, and Environmental Decision-Making (SUCCEED) is a K-12 Outreach program created by - University’s Department of Engineering and Pub...

Plastics production is responsible for 1% and 3% of U.S. greenhouse gas (GHG) emissions and primary energy use, respectively. Replacing conventional plastics with bio-based plastics (made from renewable feedstocks) is frequently proposed as a way to mitigate these impacts. Comparatively little research has considered the potential for green energy...

Preparing a literate public to critically evaluate issues related to climate change, energy, and the environment is an important pillar toward more sustainable societies. In this article, we focus on how informal education and outreach programs that have a combined focus on science, technology, engineering, and mathematics (STEM) and on climate cha...

SrSn2Ga1.3Cr2.7O11 is shown to be a strongly geometrically frustrated magnet through measurement of its temperature-dependent magnetic susceptibility and specific heat. This material, determined by powder neutron diffraction to have an R-type ferrite crystal structure, has S=3/2 Cr3+ ions in isolated Kagomé planes with no magnetic ions in the inter...

PbMn(SO4)(2) has been synthesized in an evacuated quartz tube. The nuclear and magnetic crystal structures have been determined using powder X-ray and neutron diffraction. This material crystallizes in the enantiomorphic space group pair P4(1)2(1)2(#92) and P4(3)2(1)2(#96), forming a double-helical arrangement of Pb2+ and Mn2+ cations. The Mn2+O6 o...

A new family of anhydrous sulfates, A2+Mn5(SO4)6 (A=Pb, Ba, Sr) is reported. The crystal structures of PbMn5(SO4)6 and SrMn5(SO4)6 are solved by powder X-ray and neutron diffraction. BaMn5(SO4)6 is isostructural. PbMn5(SO4)6 crystallizes with P3¯ symmetry and unit cell parameters of a=14.551(1) Å and c=7.535(1) Å. The structure has rich features, i...

A new family of anhydrous sulfates, A2+Mn5(SO4)6 (A ¼ Pb, Ba,Sr) is reported. The crystal structures of PbMn5(SO4)6 and SrMn5(SO4)6 are solved by powder X-ray and neutron diffraction. BaMn5(SO4)6 is isostructural. PbMn5(SO4)6 crystallizes with P3 symmetry and unit cell parametersof a ¼ 14.551(1)A˚ and c ¼ 7.535(1)A˚ . The structure has rich feature...