Emissions Of Hydrofluorocarbons Research Articles

Scenario analysis of hydrofluorocarbons consumption and emission reduction in China's mobile air-conditioning sector

The automobile air conditioning industry is an important consumption area of hydrofluorocarbons (HFCs), and the analysis of the use and emission reduction of HFCs in this industry is of great significance for environmental protection. This study aims to measure and analyze the HFC consumption and emission reduction in China's MAC industry and the cost of emission reduction in automobile enterprises through an in-depth analysis, to provide a scientific basis for the formulation of relevant policies and to support the country in achieving HFC emission reduction targets in the field of environmental protection. In this study, the Gompertz model combined with the vehicle survival rate Weibull was used to predict the vehicle ownership and sales in China, and then the HFC consumption and emission reduction in China's MAC industry and the cost of emission reduction in automobile enterprises were measured and analyzed with reference to the experience of relevant domestic and foreign measurement models. The results show that under the four scenarios of R27-X29, R29-X29, R29-X29, and R29-X35, the cumulative use of HFCs will be reduced by 61.44%−73.19%, and the cumulative emission will be reduced by 51.85%−64.55% in the period of 2023–2060, while the cumulative abatement cost of the automobile enterprises in the period of 2023–2060 will be RMB 419.31–481.02 billion. 481.02 billion yuan. The adoption of a policy banning HFCs refrigerants in M1 and N1 vehicles has a significant effect on reducing HFCs consumption and emissions, and the abatement cost will decrease with the expiration of new refrigerant patents, increased demand, and technological advancements.

The Social Costs of Hydrofluorocarbons and the Large Climate Benefits from their Expedited Phasedown.

Hydrofluorocarbons are a potent greenhouse gas, yet there remains a lack of quantitative estimates of their social cost. The present study addresses this gap by directly calculating the social cost of hydrofluorocarbons (SC-HFCs) using perturbations of exogenous inputs to integrated assessment models. We first develop a set of direct estimates of the SC-HFCs using methods currently adopted by the United States Government, and then derive updated estimates that incorporate recent advances in climate science and economics. We compare our estimates with commonly used social cost approximations based on global warming potentials to show that the latter is a poor proxy for direct calculation of hydrofluorocarbon emissions impacts using IAMs. Applying our SC-HFCs to the Kigali Amendment, a global agreement to phase down HFCs, we estimate that it provides $37 trillion (2020USD) in climate benefits over its lifetime. Expediting the phasedown could increase the estimated climate benefits to $41 trillion (2020USD).

On the Influence of Hydroxyl Radical Changes and Ocean Sinks on Estimated HCFC and HFC Emissions and Banks

AbstractHydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) are potent greenhouse gases regulated under the Montreal Protocol and its amendments. Emission estimates generally use constant atmospheric lifetimes accounting for loss via hydroxyl radical (OH) reactions. However, chemistry‐climate models suggest OH increases after 1980, implying underestimated emissions. Further, HCFCs and HFCs are soluble in seawater and could be destroyed through in situ oceanic microbial activity. These ocean sinks are largely overlooked. Using a coupled atmosphere‐ocean model, we show that increases in modeled OH imply underestimated HCFC and HFC emissions by ∼10% near their respective peak emissions. Our model results also suggest that oceanic processes could lead to up to an additional 10% underestimation in these halocarbon emissions in the 2020s. Ensuring global compliance to the Protocol and accurate knowledge of contributions to global warming from these gases therefore requires understanding of these processes.

Projections of National-Gridded Emissions of Hydrofluoroolefins (HFOs) in China.

Hydrofluoroolefins (HFOs) are being used as substitutes for potent greenhouse gas hydrofluorocarbons (HFCs). However, the use and environmental impacts of HFOs are of great concern due to the rapid degradation of HFOs to produce persistent and phytotoxic trifluoroacetic acid (TFA). Here, we provide a comprehensive projection of HFO emissions in China during 2024-2060 for the first time. Under the Kigali Amendment to the Montreal Protocol, China's HFO emissions are estimated to increase from 1.7 (1.3-2.3) to 148.8 (111.4-185.4) kt in 2024-2060 with cumulative emissions of 2.8 (2.0-3.5) Gt, and cumulative reduced HFCs emissions are evaluated to be 5.4 Gt CO2-equivalent. High HFO emissions would be distributed mainly in the North China Plain and the eastern and coastal areas. HFO-1234yf (2,3,3,3-tetrafluoropropene) contributes most of HFO emissions with a cumulative emission of 1.7 Gt in 2024-2060, while the cumulative increment of TFA deposition from HFO-1234yf emissions would reach 0.4-1.0 Gt. The long-term national-gridded HFO emission inventories can provide scientific support for evaluating the environmental risks of HFOs and developing HFC phase-out pathways for addressing climate change.

Banks, emissions, and environmental impacts of China's ozone depletion substances and hydrofluorocarbon substitutes during 1980–2020

Ozone-depleting substances (ODSs), which also contribute to global warming, have been controlled by the Montreal Protocol (MP) since 1987. China joined the MP in 1991 and began reducing production and consumption of ODSs in the country, leading to a decrease in emissions of ODSs. Based on the Intergovernmental Panel on Climate Change guidelines, the latest emission factors and actual consumption in China (MP scenario), both the historical banks and the historical emissions of ODSs and substitute hydrofluorocarbons (HFCs) during 1980–2020 were calculated. To understand the reduction in ODS and HFC emissions by implementing the MP, we also estimated China's virtual emissions (NMP, i.e., the amount of ODS emissions without the MP) over the same period. The avoided cumulative ODS consumption and emission values of 10.8 and 5.8 (4.8–6.9) million tonnes (Mt) of CFC-11-equivalent (eq), respectively, were estimated by comparing the two scenarios. Furthermore, 26 (22−33) giga tonnes (Gt) of CO2-eq emissions, equivalent to an increase of 0.031 W m−2 radiative forcing, were estimated to be avoided by 2020, which will prevent an additional 0.025 °C increase in temperature. The MP implemented by China has resulted in substantial environmental benefits over the last 30 years. However, owing to the massive use of HFCs as substitutes, the cumulative emissions reached 2286 Mt. CO2-eq during 1990–2020, and it will be challenging to phase down HFCs in the environment after China ratified the Kigali Amendment in 2021.

Pathway and Cost-Benefit Analysis to Achieve China's Zero Hydrofluorocarbon Emissions.

Global hydrofluorocarbon (HFC) cumulative emissions will be more than 20 Gt CO2-equiv during 2020-2060 and have a non-negligible impact on global warming even in full compliance with the Kigali Amendment (KA). Fluorochemical manufacturers (including multinationals) in China have accounted for about 70% of global HFC production since 2015, of which about 60% is emitted outside China. This study built an integrated model (i.e., DECAF) to estimate both territorial and exported emissions of China under three scenarios and assess the corresponding climate effects as well as abatement costs. Achieving near-zero territorial emissions by 2060 could avoid 23 ± 4 Gt CO2-equiv of cumulative territorial emissions (compared to the 2019 Baseline scenario) during 2020-2060 at an average abatement cost of 9 ± 6 USD/t CO2-equiv. Under the near-zero emission (including territorial and abroad) pathway, radiative forcing from HFCs will peak in 2037 (60 ± 6 mW/m2) with a 33% peak reduction and 8 years in advance compared to the path regulated by the KA, and the radiative forcing by 2060 will be lower than that in 2019. Accelerated phase-out of HFC production in China could provide a possibility for rapid global HFC abatement and achieve greater climate benefits.

Enhancing R410A blend separation by using ionic liquids: From UNIFAC model extension, solvent design to molecular dynamics simulation

The selective separation of refrigerants could facilitate their reclamation and reduce emissions of hydrofluorocarbons (HFC) with high global warming potential. R410A, a near azeotropic mixture comprising equimass difluoromethane (R-32) and pentafluoroethane (R-125), is required to be phased out and shortly replaced by more efficient and sustainable refrigerants. Under this background, the recovery of R-32 and R-125 by using ionic liquids (ILs) as the solvent is considered as a promising approach. In this work, the rational selection of ILs for enhancing the R410A separation is presented. To this end, 873 refrigerant-in-IL solubility data (573 for R-32, 300 for R-125) are firstly adopted for the extension of the UNIFAC-IL model to cover the R410A system. With the obtained UNIFAC-IL model, a computer-aided IL design (CAILD) task is cast as a mixed-integer nonlinear programming (MINLP) problem, which is solved to identify three top-ranked ILs. Following that, molecular dynamics (MD) simulations of the selected IL-refrigerant systems are conducted, which well elucidate the reliability of the CAILD results.

Social media data shed light on air-conditioning interest of heat-vulnerable regions and sociodemographic groups

Cooling homes with air conditioners is a vital adaptation approach, but the wider adoption of air conditioners can increase hydrofluorocarbon emissions that have high global warming potential and carbon emissions as a result of more fossil energy consumption. The scale and scope of future cooling demand worldwide are, however, uncertain because the extent and drivers of air-conditioning adoption remain unclear. Here, using 2021 and 2022 Facebook and Instagram data from 113 countries, we investigate the usability of social media advertising data to address these data gaps in relation to the drivers of air-conditioning adoption. We find that social media data might represent air-conditioning purchasing trends. Globally, parents of small children and middle-aged, highly educated married or cohabiting males tend to express greater interest in air-conditioning adoption. In regions with high heat vulnerability yet little empirical data on cooling demand (e.g., the Middle East and North Africa), these sociodemographic factors play a more prominent role. These findings can strengthen our understanding of future cooling demand for more sustainable cooling management.

SIMULATION OF THE IMPACT OF HYDROFLUOROCARBON (HFC) EMISSIONS IN TOGO ON GLOBAL AVERAGE TEMPERATURE

Background:Several IPCC scenarios have predicted a global temperature increase of 1.5°C by 2030 attributable to greenhouse gases (GHGs) including hydrofluorocarbons (HFCs) controlled by the Kigali Amendment. Objectives:Thus, this study aims to simulate the increase in global temperature by 2030 attributed only to HFC emissions in Togo, given that the country is a party to the Kigali amendment and the Paris agreement. Methods:The methodology applied in this study is based on the projection to 2030 of HFC emissions in 2018 in order to simulate their impact on global average temperature using the LEAP-IBC tool. Results:HFCs emissions in Togo will reach 2598.13 GgCO2-e and will contribute to the increase in global average temperature by representing 18/100000 of the 0.5°C over the period 2018 to 2030 predicted by the IPCC scenarios. This increase attributed to the HFCs sector alone in Togo once again shows the impact of GHG on global average temperature.These results should therefore alert political decision-makers to redouble their efforts in the implementation of mitigation measures.

Simulation of an energy-efficient cool roof with cellulose-based daytime radiative cooling material

Conventional air conditioners are considered the most energy-intensive components in residential and tertiary buildings. Besides high energy consumption, they are also harmful to the environment due to the emissions of hydrofluorocarbons into the atmosphere. Night sky cooling or radiative cooling is a naturally occurring phenomenon that takes advantage of the atmospheric transparency window in the wavelength range of 8–13 µm to effectively dissipate heat from a surface into outer space. However, this can only occur at night, which is incompatible with the cooling demand that peaks during the day. This paper aims to develop a cool roof that relies on a daytime radiative cooling (DRC) material with low solar absorptivity in the wavelength range of 0.3–2.5 µm and high emissivity in the atmospheric window. The used DRC material is derived from cellulose acetate-based films, which are recyclable, sustainable, and bioclimatic. This material is used to improve the energy efficiency of an existing building by reducing the temperature of the roof to improve the thermal comfort of the building in the framework of Moroccan climatic zones. Software simulations are used to assess the needs and the demand of the building and simulate the impact of the smart device on the building's thermal performance and evaluate the thermophysical and optical properties of the DRC material. This latter material will be compared with another DRC material based on titanium dioxide and silicon dioxide mixture coating in terms of cooling performances. Results have shown a drastic sub ambient cooling of more than 3 °C and a great reduction in the indoor temperature of the building and a reduction in the total electricity consumption of up to 60.38 %.

Transitioning to low-GWP alternatives with enhanced energy efficiency in cooling non-residential buildings of China.

The electricity demand for space cooling in the non-residential building (NRB) sector of China is growing significantly and is becoming increasingly critical with rapid economic development and mounting impacts of climate change. The growing demand for space cooling will increase global warming due to emissions of hydrofluorocarbons used in cooling equipment and carbon dioxide emissions from the mostly fossil fuel-based electricity currently powering space cooling. This study uses the Greenhouse Gas and Air Pollution Interaction and Synergies (GAINS) model framework to estimate current and future emissions of hydrofluorocarbons and their abatement potentials for space cooling in the NRB sector of China and assess the co-benefits in the form of savings in electricity and associated reductions in greenhouse gas (GHG), air pollution, and short-lived climate pollutant emissions. Co-benefits of space cooling are assessed by taking into account (a) regional and urban/rural heterogeneities and climatic zones among different provinces; (b) technical/economic energy efficiency improvements of the cooling technologies; and (c) transition towards lower global warming potential (GWP) refrigerants under the Kigali Amendment. Under the business-as-usual (BAU) scenario, the total energy consumption for space cooling in the NRB sector will increase from 166 TWh in 2015 to 564 TWh in 2050, primarily due to the rapid increase in the floor space area of non-residential buildings. The total GHG mitigation potential due to the transition towards low-GWP refrigerants and technical energy efficiency improvement of cooling technologies will approximately be equal to 10% of the total carbon emissions from the building sector of China in 2050.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11027-022-10021-w.

Projections of hydrofluorocarbon (HFC) emissions and the resulting global warming based on recent trends in observed abundances and current policies

Abstract. The emissions of hydrofluorocarbons (HFCs) have increased significantly in the past 2 decades, primarily as a result of the phaseout of ozone-depleting substances under the Montreal Protocol and the use of HFCs as their replacements. In 2015, large increases were projected in HFC use and emissions in this century in the absence of regulations, contributing up to 0.5 ∘C to global surface warming by 2100. In 2019, the Kigali Amendment to the Montreal Protocol came into force with the goal of limiting the use of HFCs globally, and currently, regulations to limit the use of HFCs are in effect in several countries. Here, we analyze trends in HFC emissions inferred from observations of atmospheric abundances and compare them with previous projections. Total CO2 eq. inferred HFC emissions continue to increase through 2019 (to about 0.8 GtCO2eq.yr-1) but are about 20 % lower than previously projected for 2017–2019, mainly because of the lower global emissions of HFC-143a. This indicates that HFCs are used much less in industrial and commercial refrigeration (ICR) applications than previously projected. This is supported by data reported by the developed countries and the lower reported consumption of HFC-143a in China. Because this time period preceded the beginning of the Kigali provisions, this reduction cannot be linked directly to the provisions of the Kigali Amendment. However, it could indicate that companies transitioned away from the HFC-143a with its high global warming potential (GWP) for ICR applications in anticipation of national or global mandates. There are two new HFC scenarios developed based (1) on current trends in HFC use and Kigali-independent (K-I) control policies currently existing in several countries and (2) current HFC trends and compliance with the Kigali Amendment (KA-2022). These current policies reduce projected emissions in 2050 from the previously calculated 4.0–5.3 GtCO2eq.yr-1 to 1.9–3.6 GtCO2eq.yr-1. The added provisions of the Kigali Amendment are projected to reduce the emissions further to 0.9–1.0 GtCO2eq.yr-1 in 2050. Without any controls, projections suggest a HFC contribution of 0.28–0.44 ∘C to global surface warming by 2100, compared to a temperature contribution of 0.14–0.31 ∘C that is projected considering the national K-I policies current in place. Warming from HFCs is additionally limited by the Kigali Amendment controls to a contribution of about 0.04 ∘C by 2100.

Scenario analysis of hydrofluorocarbons emission reduction in China's mobile air-conditioning sector

With the Kigali Amendment (KA) coming into effect in China, the control of hydrofluorocarbons (HFCs) emissions has become more imperative. The mobile air-conditioning (MAC) sector is one of the important HFCs consumer sectors, and therefore studying its feasible mitigation paths and costs is of great significance to China's successful implementation of KA. This study used the bottom-up method with updated emission factors to re-evaluate the emission inventory of HFCs from the MAC sector in China from 2005 to 2020. The average annual growth rate of HFCs consumption in the MAC sector is 9.8%, and HFCs emissions have increased from 5.8 (5.3–6.2) kt in 2005 to 22.2 (20.6–23.8) kt in 2020, with an average annual growth rate of 8.8%. Using the Gompertz model combined with the Weibull function of vehicle survival rate, the ownership and new registrations of internal combustion engine vehicles (ICEVs) and electric vehicles (EVs) in China are predicted. The ownership of ICEVs and EVs is projected to be 310 million and 91 million in 2030, respectively and 2 million and 641 million in 2060, respectively. HFCs emissions in the MAC sector would reach 59.8 (55.3–64.3) kt (80.0–93.0 Mt CO2-eq) in 2060 if without any control measure. To implement the KA, the cumulative of 1.6 Gt CO2-eq emissions would be reduced. Under the other two accelerated mitigation scenarios, the MAC sector's HFCs will reach their emissions peak in 2028 and 2025 and achieve zero emissions in 2050 and 2046, respectively. Under the accelerated mitigation with recovery scenario, the cumulative emissions are only 15.0% of the business as usual (BAU) scenario. Using HFO-1234yf as the substitute, the unit abatement cost of the MAC sector is 27.3–37.4 USD t−1 CO2-eq.

Achieving Paris climate goals calls for increasing ambition of the Kigali Amendment

Hydrofluorocarbon emissions have increased rapidly and are managed by the Kigali Amendment to the Montreal Protocol. Yet the current ambition is not consistent with the 1.5 °C Paris Agreement goal. Here, we draw on the Montreal Protocol start-and-strengthen approach to show that accelerated phase-down under the Kigali Amendment could result in additional reductions of 72% in 2050, increasing chances of staying below 1.5 °C throughout this century.

Integrated modeling of human-earth system interactions: An application of GCAM-fusion

Typically in human-earth system modeling studies, feedbacks between the earth and human systems are analyzed by passing information between independent models. The reliance on existing Earth System Model outputs limits the ability to explore feedbacks under arbitrary scenarios and equally important limits the ability to explore large-scale uncertainty in these interactions. In this study we explore a wide range of climate uncertainties and incorporate the implications of increased cooling hydrofluorocarbons emissions. We implement a statistical relationship between global mean temperature change and heating and cooling degree days that allows us to produce changes in building energy demands within GCAM at every time step and every region. While there is a general agreement in the literature that increasing temperatures will increase cooling energy demands and decrease heating energy demands, there has been no fully-coupled analysis of this dynamic that would, for example, account for the feedbacks on hydrofluorocarbons from increased cooling demands. The variation in the spatial distribution of temperatures leads to substantial variation in the change in cooling and heating energy across regions, with regions like USA, India and Sub-Saharan Africa experiencing a factor of two difference in cooling demands. While the feedbacks between building energy demand and global mean temperature are modest by themselves, this study prompts future research on coupled human-earth system feedbacks, in particular in regards to land, water, and other energy infrastructure.

Evidence of a recent decline in UK emissions of hydrofluorocarbons determined by the InTEM inverse model and atmospheric measurements

Abstract. National greenhouse gas inventories (GHGIs) are submitted annually to the United Nations Framework Convention on Climate Change (UNFCCC). They are estimated in compliance with Intergovernmental Panel on Climate Change (IPCC) methodological guidance using activity data, emission factors and facility-level measurements. For some sources, the outputs from these calculations are very uncertain. Inverse modelling techniques that use high-quality, long-term measurements of atmospheric gases have been developed to provide independent verification of national GHGIs. This is considered good practice by the IPCC as it helps national inventory compilers to verify reported emissions and to reduce emission uncertainty. Emission estimates from the InTEM (Inversion Technique for Emission Modelling) model are presented for the UK for the hydrofluorocarbons (HFCs) reported to the UNFCCC (HFC-125, HFC-134a, HFC-143a, HFC-152a, HFC-23, HFC-32, HFC-227ea, HFC-245fa, HFC-43-10mee and HFC-365mfc). These HFCs have high global warming potentials (GWPs), and the global background mole fractions of all but two are increasing, thus highlighting their relevance to the climate and a need for increasing the accuracy of emission estimation for regulatory purposes. This study presents evidence that the long-term annual increase in growth of HFC-134a has stopped and is now decreasing. For HFC-32 there is an early indication, its rapid global growth period has ended, and there is evidence that the annual increase in global growth for HFC-125 has slowed from 2018. The inverse modelling results indicate that the UK implementation of European Union regulation of HFC emissions has been successful in initiating a decline in UK emissions from 2018. Comparison of the total InTEM UK HFC emissions in 2020 with the average from 2009–2012 shows a drop of 35 %, indicating progress toward the target of a 79 % decrease in sales by 2030. The total InTEM HFC emission estimates (2008–2018) are on average 73 (62–83) % of, or 4.3 (2.7–5.9) Tg CO2-eq yr−1 lower than, the total HFC emission estimates from the UK GHGI. There are also significant discrepancies between the two estimates for the individual HFCs.

A review of bottom-up and top-down emission estimates of hydrofluorocarbons (HFCs) in different parts of the world

Hydrofluorocarbons (HFCs) are widespread alternatives for the ozone-depleting substances chlorofluorocarbons and hydrochlorofluorocarbons. They are used mainly as refrigerants or as foam-blowing agents. HFCs do not deplete the ozone layer, but they are very potent greenhouse gases, already contributing to global warming. Since 2019 HFCs are regulated under the Kigali Amendment to the Montreal Protocol, which demands reliable emission estimates to monitor the phase-down. Quantification of emissions is performed with two methods: bottom-up from product inventories or data on chemical sales; or top-down, inferred from atmospheric measurements by inverse modelling or interspecies correlation. Here, we review and compare the two methods and give an overview of HFC emissions from different parts of the world. Emission estimates reported by the different methods vary considerably. HFC emissions of developed countries (Annex I) are reported to the United Nations Framework Convention on Climate Change. These bottom-up estimates add up to only half of global emissions estimated from atmospheric data. Several studies with regional top-down estimates have shown that this gap is not owed to large-scale underreporting of emissions from developed countries, but mostly due to emissions from developing countries (non-Annex I). China accounts for a large fraction of the emissions causing the gap, but not entirely. Bottom-up and top-down estimations of emissions from other developing countries that could identify other large emitters are largely unavailable. Especially South America, West-, Central- and East-Africa, India, the Arabian Peninsula and Northern Australia are not well covered by measurement stations that could provide atmospheric data for top-down estimates.

О влиянии Кигалийской поправки к Монреальскому протоколу на будущие выбросы гидрофторуглеродов в России

Hydrofluorocarbons (HFCs) are anthropogenic greenhouse gases with high global warming potentials. Hydrofluorocarbons are subject to the United Nations Framework Convention on Climate Change, the Kyoto Protocol and the Paris Agreement, but these international agreements impose limits on aggregate emissions of all greenhouse gases in each of the participating countries, not specifically limiting either hydrofluorocarbon emissions or individual emissions of other greenhouse gases. This changed with the adoption of the Kigali Amendment to the Montreal Protocol on Substances that Deplete the Ozone Layer in 2016. The amendment provides for a phased reduction in the production and consumption of hydrofluorocarbons, i.e. a reduction in activities that result in emissions of hydrofluorocarbons to the atmosphere. The Russian Federation acceded to the Kigali Amendment in 2020. The article considers the atmospheric content of hydrofluorocarbons, the world and Russian dynamics and the structure of their emissions to the atmosphere. In Annex I Parties to the UNFCCC, emissions from HFCs use predominate (92.0% of the total emission in 2018), while emissions from production dominate in China, where the world’s major production capacity is concentrated. In Russia, prior to 2000, total HFCs emissions almost entirely originated from the chemical industry. Since 2000, emissions from the use of hydrofluorocarbons have increased rapidly in various applications, where HFCs replace the phasing-out ozone-depleting substances. In 2016-2018, the share of emissions from the use of HFCs in the total emission was between 43 and 61%. The authors have made a projection of hydrofluorocarbon emissions from their use in the Russian Federation in various industries and activities up to 2065. It is shown that if the consumption of HFCs remains at 2018 level their emissions stabilize in the first half of the 40s of the XXI century at about 30-40 Mt СО2-eq., 1.5-2 times above the current level. Provided that Russia complies with the Kigali Amendment, the growth of emissions will initially continue reaching their maximum in 2024-2028. After 2055, subject to efficient collection and disposal of HFCs from decommissioned equipment, emissions will stabilize at about 4 Mt СО2-eq. (25% of 2018 emissions). In the absence of collection and utilization of HFCs, the maximum is expected several years later, and stabilization will occur after 2060 at the level of 6 Mt СО2-eq.

Review and estimation of global halocarbon emissions in the buildings sector

Estimates of the non-CO2 greenhouse gas (GHG) emissions contributed by the buildings sector are necessary to evaluate this sector’s potential for climate change mitigation. As data is lacking on fluorinated gases (F-gases) and hydrofluorocarbon (HFC) emissions from the buildings sector, this study aimed to estimate these emissions. First, the share of total global GHG emissions represented by buildings-sector emissions was estimated. Then, the HFC emissions of the buildings sectors in several countries (USA, EU, Japan, and China) are compiled. Next, based on necessary assumptions, global buildings-sector HFC emissions were estimated. Finally, this paper discusses implications for policy-makers.

A roadmap investment strategy to reduce carbon intensive refrigerants in the food retail industry

High global warming potential (GWP) refrigerant leakage is the second-highest source of carbon emissions across UK supermarket retailers and a major concern for commercial organisations. Recent stringent UN and EU regulations promoting lower GWP refrigerants have been ratified to tackle the high carbon footprint of current refrigerants. This paper introduces a data-driven modelling framework for optimal investment strategies supporting the food retail industry to transition from hydrofluorocarbon (HFC) refrigeration systems to lower GWP systems by 2030, in line with EU legislation. Representative data from a UK food retailer is applied in a mixed integer linear model, making simultaneous investment decisions across the property estate. The model considers refrigeration-system age, capacity, refrigerant type, leakage and past performance relative to peer systems in the rest of the estate. This study proposes two possible actions for high GWP HFC refrigeration systems: a) complying with legislation by retrofitting with an HFO blend (e.g. R449-A) or b) installing a new natural refrigerant system (e.g. R744). Findings indicate that a standard (i.e. business-as-usual) investment level of £6 m/yr drives a retrofitting strategy enabling significant reduction in annual carbon emissions of 71% by the end of 2030 (against the 2018 baseline), along with meeting regulatory compliance. The strategy is also highly effective at reducing emissions in the short term as total emissions during the 12-year programme are 59% lower than would have been experienced if the HFC emissions continued unabated. However, this spending level leaves the business at significant risk of refrigeration system failures as necessary investments in new systems are delayed resulting in an ageing, poorly performing estate. The model is further tested under different budget and policy scenarios and the financial, environmental, and business-risk implications are analysed. For example, under a more aggressive investment approach of £50 m/yr carbon reductions are at 93% by the end of 2030, whilst also ensuring compliance with the legislative cut-off four years early in 2026 and substantially enhancing the reliability of the refrigeration systems in the portfolio. Alternatively, when emissions are minimised instead of cost with a £50 m/yr investment level, 99% decarbonisation is achieved by 2030. Overall, the study highlights the trade-offs between capital investment and system resilience requiring a careful balance of priorities and the need to have up to date information so decision makers can reliably drive a successful strategy towards more sustainable operation of refrigeration systems.