How should we evaluate different climate mitigation strategies? Even for an ambitious 1.5°C target, several mitigation strategies are plausible – from a high dependence on new energy infrastructures, to low-demand pathways, and a breadth of scenarios in between1. Evaluating these options mostly from a macroeconomic cost-benefit perspective is relevant, but it fails to reflect the benefits and costs of mitigation strategies from a wellbeing perspective2. There are three closely related shortcomings. First, mitigation options on the demand-side, such as shifts in transport patterns and building design, size and use, interact with the wellbeing of end-users and citizens. Evaluating the marginal monetary costs of these measures, if they can be monetized at all, hardly reflects their full impacts. Second, a focus on costs leads to a tendency to preferably evaluate those solutions that have precise costs values attached, neglecting more systemic or uncertain solutions where price tags are difficult to evaluate or not relevant3. Third, income and expenditures only reflect a part of wellbeing, and monetary cost evaluations, even if starting from a broader framework, often ignore encompassing views on wellbeing. This critique is not new, and on the aggregate scale, there is agreement among economists and philosophers and other disciplines that metrics like GDP insufficiently reflect wellbeing, and that these must be replaced by more encompassing metrics4.
These considerations motivate us to ask how to evaluate climate mitigation strategies by explicitly relating them to human wellbeing. This is a considerable challenge, as there is no single straightforward and agreed upon metric of wellbeing. Wellbeing can be considered on macro level, e.g. in 10 country-level wellbeing domains by the OECD5, and on micro-level, reflected, for example individual constituents of wellbeing36. Approaches can also be separated into subjective understandings of wellbeing (given preferences, happiness) and objective ones (life expectancy, eudaimonic metrics) with diverging implications for climate change mitigation8,9. According to some leading eudaimonic approaches, wellbeing has several constituents, and that all of these must be met independently to enable a good life10,11. Here, we follow this understanding and examine individual metrics and constituents of wellbeing. We first group demand-side climate solutions into avoid, shift, and improve categories, estimate their respective potentials across sectors (Methods), then ask how they improve or harm individual constituents of wellbeing (Table S1), systematically coding their impact on constituents of wellbeing based on literature review (Methods). We find that demand-side solutions harbor considerable potential both for climate change mitigation and improved well-being but remain scarcely applied. We discuss three barriers that hinder the realization of demand-side climate change mitigation options.
Demand-side options can reduce GHG emissions in all end-use sectors by at least 50%
We understand demand-side options as mitigation opportunities that involve individuals or industrial end users of products, services or processes. These are distinct from supply side options that involve changes in energy supply and deployment of carbon dioxide removal technologies that can be considered independent of demand. Demand-side options can be grouped into avoid, shift, and improve categories, constituting a simple analytical framework pertinent for decision makers12. Originally applied to the transport sector13, avoid, shift, and improve categories can also be transferred to other sectors12,14. Here, we generalize ‘avoid’ to all mitigation options that reduce wasteful energy consumption by redesigning service provisioning systems; ‘shift’ to the switch to already existing competitive low-carbon technologies and service provisioning systems; and ‘improve’ to improvements in efficiency in existing technologies where adoption by end users plays an important role.
We categorize demand-side mitigation strategies along avoid, shift and improve categories (Figure 1, Table 1). In all sectors, end-use strategies can reduce the majority of emissions, ranging from 41% (6.6 GtCO2) emission reductions in the industry sector (median estimate), to 49% (8.9 GtCO2) in the food sectors, to 69% (5.6 GtCO2) emission reductions in the land transport sector, and 81% (7.1 GtCO2) in the building sector. These numbers are median estimates. Estimates are approximation, as they are simple products of individual assessments for each of the three “avoid”, “shift” and “improve” options. If interactions were taken into account, the- full potentials may be higher or lower, independent of relevant barriers to realizing the median potential estimates. Potentials only involve decisions that can be done by end-users, and ignore supply side options, such as the decarbonization of the electricity sector. However, potentials include technology adoption that reduces carbon intensity, e.g., embedded renewable energy in housing and electric vehicles for transport.
We find that improve options contribute the most in building, transport and industry sectors. Examples include efficient building envelope, household appliances, electric cars, and more efficient material and energy use in industrial production. Shift measures are most relevant for transport, in particular modal shift to walking, cycling, and shared pooled mobility; and for food, in particular shift to flexitarian, vegetarian, vegan, or other healthy diets. These are options that require physical infrastructures and choice infrastructures that support low-carbon choices, such as safe and convenient transit corridors, and desirable and affordable meat-free menu options. Of course, they also require end users to adopt these choices, individually and socially. Avoid options are relevant in all sectors. Cities play an additional role, as more compact designs and higher accessibility reduce demand for km travel and car mobility, but also induce lower average floor size and corresponding heating and cooling demand. The lifetime extension of products and more efficient product design also add to avoiding energy use and related emissions. Teleworking is related to high uncertainty with relatively low potential in consequential assessments, but with possibly higher emission reduction potential if COVID-19 experiences induce a more structural shift in working environments from both employees and employers.
Table 1: Demand-side mitigation strategies and potentials over sectors
Sector
|
Gt CO2 in 2050
|
Mitigation Strategy
|
Changes in CO2 for ASI
|
References
|
Housing, leisure and services (Building)
(total mitigation potential: 81%, 7.1 GtCO2)
|
8.8
|
Avoid: Sufficiency of energy and resources (include Compact city and Nature based solution from Urban sector)
Building design, size and use (behavioral and lifestyle change)
|
10-40%
[median: 25%]
|
IEA 202015; Ürge-Vorsatz et al. 202016; Niamir et al. 202017; Ahl et al. 201918; IGES et al. 201919; ECF 201820; Virage-énergie 201621
|
Shift: Improve access and switch to renewables
On-site renewables, micro-grids, switch to lower carbon fuels and electrification for spaceheating, cooling, cooking, hot water and electrical uses
|
30-70%
[median: 50%]
|
IEA 202015; Niamir et al. 202022; Mastrucci & Rao 201923; IGES et al. 201919; ECF 201820; Mata et al. 201824; Virage-énergie 201621
|
Improve: Efficiency
Improved building envelope, improved building technical systems (for HVAC, cooking and electrical uses), smart home and digitalization, efficient appliances, control systems, clean cooking
|
30-70%
[median: 50%]
|
IEA 202015; Mata et al. 202025; IGES et al. 201919; Ellsworth-Krebs et al. 201926; ECF 201820; Virage-énergie 201621
|
Mobility, accessibility
(Land Transport)(total mitigation potential: 69%, 6.5 GtCO2)
|
9.5
|
Avoid: Active travel in highly accessible cities; teleworking
supported by compact highly accessible city design and safe infrastructures for pedestrians and cyclists.
Teleworking or telecommuters partially or entirely replace their out-of-home work activities by working at home or at locations close to home
|
1-15%
[median: 10%]
|
Brand et al. 202027; Creutzig et al. 201528 & 20162; Ivanova et al. 202029; Riggs 202030;
|
Shift: Shared mobility and convenient and safe public transit
Pooled shared mobility with high occupancy and micro-mobility with high lifetime of vehicle stock; convenient rail-based public transit; supported by urban design and transit-oriented development resulting in reduced travel distances; logistic optimization in last-mile freight.
|
0-40%
[median: 30%]
|
ITF, 202031,32; ITF, 201733,34; Creutzig et al. 20162; ITF, 201635
|
Improve: EVs
Electric Vehicles when charged with the electricity generated from medium decarbonized power system (IEA stated policies); Behavior change programs on the socio-economic structures that impede adoption of EV’s; the urban structures that enable reduced car dependence and how EV’s can assist grids; and the synergies between emerging technologies and shared economy to maximizing the greater benefit of EVs
|
30-100%
[median: 50%]
|
EEA, 201836; Hill et al 201937; Lutsey 2015; Plötz et al 201738; Khalili et al 201939
|
Nutrition (Food)
(total mitigation potential: 49%, 8.9 GtCO2)
|
18
|
Avoid: Food waste
|
8-25%
[median: 15%]
|
Poore and Nemecek, 201840; Schanes et al. 201841; Gunders & Bloom 201742
IPCC SRCCL, 201943
|
Shift: Animal free protein
Switch to animal free protein sources such as soy, lentils, other pulses and meat substitute products.
|
18-87%
[median: 40%]
|
Semba et al. 202044; Springmann et al. 201845; Willett et al. 201946; Parodi et al. 201847; IPCC SRCCL, 201943
|
Industry
(total mitigation potential: 41%, 6.5 GtCO2)
|
15.8
|
Avoid: Materials efficient services
Avoid materials via dematerialization, the sharing economy, materials-efficient and lightweight designs, and yield improvements in manufacturing.
|
5%-22%
[median: 13%]
|
IEA 202015,48; Grubler et al. 201849; Allwood and Cullen, 201550; Carruth et al., 201151
|
Avoid: Lifespan extension
Designing products so that their lifetime can be extended through repair, refurbishing, and remanufacturing, instigated via standardisation, modularity and functional segregation.
|
3%-7%
[median: 5%]
|
IEA 202015,48; Cooper et al. 201452
|
Shift: Reuse and recycling
Increasing the re-usability and recyclability of product's components. Example: dismantle old cars and re-use components for repairing other cars
|
4%-7%
[median: 5%]
|
IEA 202015,48; Ellen MacArthur Foundation, 201953; IEA 201954; Material Economics 201855
|
Improve: Energy Efficiency
Reducing the need for energy consumption through the installation of new efficient technologies and through systems and operating practices that contribute to reduce energy needs
|
25%-28% [median: 25%]
|
IEA 202015,48; Material Economics 201855
|
Aviation
(total mitigation potential: 40%, 0.7 GtCO2)
|
1.8
|
Avoid: flights
Aviation is of low economic value and demand is highly sensitive to prices. A carbon price of aviation fuel of $400/tCO2 would have demand for aviation in 2050.
|
0%-47% [median: 40%]
|
IATA 202056; Schäfer et al. 201957; Gossling et al (in review)
|
Shipping
(total mitigation potential: 69%, 1.3 GtCO2)
|
1.9
|
Avoid: Reduce demand and slow steaming
Shifting supply chains, lower demand for consumption goods, and slow steaming of ships would reduce shipping demand substantially.
|
40%-60% [median: 47%]
|
Bouman et al 201758, McKinnon 202059, ITF, 201860
|
Shift: modal shift to train
Shift from ships to long-distance train (especially across the Eurasian continent) reduces GHG emissions, but not more than 1% of expected emissions.
|
0%-1%
[median: 1%]
|
ITF, 201860
|
Improve: Design and power system
Independent of fuels (supply) better hull design and improved propulsion system can make ships highly more efficient
|
30%-50% [median: 40%]
|
Bouman et al 201758, McKinnon 202059, ITF, 201860
|
Opportunities for avoiding excess consumption exist for all end use sectors. Reducing food waste is a prime no-regret option, accounting for 4.4 GtCO2 emissions, or 8% of total annual GHG emissions, if deforestation effects associated with wasted food provision are included61. Consumers are the largest source of food waste, and habitual adjustments, such as meal planning, re-use of leftovers, and avoidance of over-preparation reduce associated GHG emissions41,42. Reregulation expiration labels is an option for policy makers to disincentive unnecessary disposal of unexpired items62. The mitigation potential of food waste reductions globally has been estimated at 0.8-6.0 GtCO2-eq yr-1 by 2050 43,63.
Diet shifts away from animal protein to plant-based protein, as another demand side strategy is even more impactful in the food sector. Estimated GHG emissions reductions associated with dietary shifts to low meat diets, vegetarian diets, or vegan diets range from 0.7-7.3, 4.3-6.4, and 7.8-8 GtCO2-eq yr-1 by 2050, respectively20.
The conceptualization of avoid-shift-improve options originated in the transport sector64. The transport sector demonstrates the largest divergence between top-down integrated assessment models and aggregation of bottom-up models. A main reason for this divergence is that place-based solutions and those that involve changing social norms and behavioral adaptations are hard to display in IAMs65. A plethora of country and city specific solutions, many of the categorized according to avoid and shift (ca. 15% and 18% of measures respectively), is estimated to have the potential to bring GHG emissions in the transport sector down to 2.5GtCO266. Key avoid strategies involve telecommuting, although total emission savings in land transport are estimated at not more than 1%67. For example, COVID-19 confinement induced telecommuting was compensated by more errands with cars, albeit at shorter distances in California30. Urban planning, street space rededication, smart logistical systems, and increased street connectivity with smaller distances have the largest potential to reduce need for travel68,69, with a counterfactual potential of 25% reduction in urban energy use in 2050 only considering newly built cities (repercussion effects in the building sector are included in this estimate)28. Improving transport nonetheless has the largest potential, in particular via electrification. In most ambitious transport energy models, a full electrification of land transport and power-to-fuels for aviation and shipping, can completely decarbonize the transport sector, while also decreasing primary energy required per unit of end use energy, in particular in electric land transport39. Vehicle leightweighting strategies can also lead to significant emissions savings through improved fuel economy70.
Avoiding energy use in buildings starts with smaller dwellings that reduce overall demand for lighting and space conditioning and smaller dwellings, shared housing, and building lifespan extension all reduce the overall demand for carbon-intensive building materials such as concrete and steel71,72. It also includes designing buildings based on bioclimatic principles to maximise energy demand reduction through nature and building typology (single-family homes versus multi-family buildings), adapting the size of buildings to the size of households redesigning both individual energy end use and building operations: replace artificial light with daylighting73,74 and use lighting sensors to avoid demand for lumens from artificial light; design passive houses using the thermal mass and smart controllers to avoid demand for space conditioning services16; eliminating standby power to reduce energy wasted in appliances/devices (this alone may reduce household energy use by 10%)75. 3D printing of buildings further reduces construction waste, optimizes the geometries and minimizes the materials content of structural elements76. Overall, ‘avoid’ potential in the building sector, reducing waste in superfluous floor space, heating and IT equipment, and energy use, is estimated at 10 and 30%, and possibly up to 50%77. Improve options, such as energy efficient appliances, insulation, and prosumer renewables on rooftops may similarly reduce GHG emissions, combined, by 50% [30-70%]16,78,79.
While demand-side solutions will change lifestyles, individuals have few opportunities to induce and realize demand-side solutions by themselves. Avoid measures require structural change in organization management (for example: working time models that enable teleworking), spatial structure (mixed use to increase accessibility with active modes), and incentives (taxing high floor space per capita to reduce wasteful resource use). Similar, shift solutions require the availability of new modes of service provision, e.g., by offering shared pooled mobility and high-quality plant-based diets, and regulation that prohibits high-emitting (and otherwise harmful) practices, such as intensive animal farming and instead promote low-carbon solutions, such as R&D spending for meat alternatives. Finally, improve options similarly require policy interventions, such as carbon pricing, banning inefficient heating systems, lightbulbs and cars with internal combustion engine and diesel motor, and mandating market shares of efficient technologies, planning procedures and practices.
Demand-side mitigation strategies improve wellbeing
Based on 406 papers (Table S3-S7), we analyze how sectoral demand-side and service-oriented mitigation strategies influence constituents of wellbeing. We systematically coded whether mitigation strategies for each sector have positive, neutral or negative impact on the 18 constituents of wellbeing introduced in Table S1. We performed expert judgement by a team of 2-4 researchers for each sector, also comprising explicit expertise on social sciences and wellbeing, and internally reviewed by at least 2 other researchers, to code impact in categories from -3 to +3 and substantiated judgement with evidence from the literature (Figure 2a). Confidence in judgement varied, because both scale and multitude of effects vary across the underlying literature. In other cases, literature was missing even when experts assumed relevant effects. Hence, we also provide confidence values, associated with each mitigation-strategy/wellbeing-constituent couple (Figure 2b) and report the confidence values also together with the results of the wellbeing evaluation below. The full table, including level of agreement and evidence and literature substantiating each entry is in the Appendix.
Demand-side mitigation strategies have positive impacts on human wellbeing (high confidence). Our study shows that among all demand-side option effects on wellbeing 76% (246 out of 324) are positive; 21.6% (70 out of 324) are neutral (or not relevant/specify); only 2.4% (8 out of 324) are negative. Active mobility (cycling and walking), efficient buildings and prosumer choices of renewable technologies have the most encompassing beneficial effects on wellbeing with no negative outcome detected. Urban and industry strategies are highly positive overall on wellbeing, but they will also reshape supply-side businesses with transient intermediate negative effects. Shared mobility, as all others, has overall highly beneficial effects on wellbeing, but also displays a few negative consequences, depending on implementation, such as a minor decrease of personal security for patrons of ridesourcing. Differentiation, however, is important. For example, shared pooled mobility provides more urban benefits, and also higher climate change mitigation potential, as compared to ridesourcing.
Positive outcomes on wellbeing are estimated to occur 19 times more often than negative outcomes in response to demand-side mitigation measures. Confidence is in 50% of all cases medium to high (between 3 and 5 on a scale from 0 to 5) but unequally distributed with higher confidence in the physical constituents than in the social constituents of wellbeing.
The highest benefits are observed in air, health and energy (all with high confidence level), food (medium confidence), mobility (high confidence), economic stability (high confidence), and water (medium-high confidence) respectively. Although the relation of demand-side mitigation strategies and the social aspects of human wellbeing is important, this has been less reflected in the literature so far, and hence our assessment finds more neutral/unknown interactions.
Wellbeing improvements are most notable in air quality (0.74 in average across all mitigation options on a scale from -1 to +1), health (0.72), and energy (0.68). These categories are also most substantiated in the literature, often under the framing of co-benefits. In many cases, co-benefits outweigh the mitigation benefits of specific GHG emission reduction strategies. This includes clean cook stoves (e.g., powered by LPG) that can improve livelihoods of more than 40% of the world population by reducing indoor air pollution80; it includes co-benefits from improved outdoor air quality in cities resulting from reduced private motorized mobility with combustion and diesel engines, and from more active mobility81,82, often associated with more accessible environment of compact cities83; and it includes a shift away from high-emission diets that would improve public health considerably, especially in high income countries84.
Food (0.51), mobility (0.46), and water (0.40) are further categories where wellbeing is improved. Only mobility has entries with highest wellbeing ranking for teleworking, compact cities, and urban system approaches. Effects on wellbeing in water and sanitation are mostly coming from building and urban solutions.
Social dimensions, such as communication, social protection, political stability and especially participation are less predominantly represented. An exception is economic stability (0.52), suggesting that demand-side options generate stable opportunities to participate in economic activities. Altogether, the literature on social constituents, in relationship to climate change mitigation, is meagre. However, there is still clear indication that many demand-side mitigation strategies have potential to improve also the social constituents of wellbeing. For example, the predominant contribution of clean cook stoves may relate to wellbeing of women, who require less time for biomass collection and cooking and can better participate in economic and social life85. Compact cities and urban system solutions have strong albeit ambiguous effects on wellbeing, and positive outcomes depend on urban design86,87.
Confidence is highest for the wellbeing dimensions air, health, and mobility, and for the mitigation options compact city, non-motorized transport and building –level sufficiency. The wellbeing dimensions education, shelter, and political stability have lowest confidence, also reflecting a respective scarcity in literature.
Opportunities for avoiding excess consumption exist for all end use sectors. Reducing food waste is a prime no-regret option, accounting for 4.4 GtCO2 emissions, or 8% of total annual GHG emissions, if deforestation effects associated with wasted food provision are included61. Consumers are the largest source of food waste, and habitual adjustments, such as meal planning, re-use of leftovers, and avoidance of over-preparation reduce associated GHG emissions41,42. Reregulation expiration labels is an option for policy makers to disincentive unnecessary disposal of unexpired items62. The mitigation potential of food waste reductions globally has been estimated at 0.8-6.0 GtCO2-eq yr-1 by 2050 43,63.
Diet shifts away from animal protein to plant-based protein, as another demand side strategy is even more impactful in the food sector. Estimated GHG emissions reductions associated with dietary shifts to low meat diets, vegetarian diets, or vegan diets range from 0.7-7.3, 4.3-6.4, and 7.8-8 GtCO2-eq yr-1 by 2050, respectively20.
The conceptualization of avoid-shift-improve options originated in the transport sector64. The transport sector demonstrates the largest divergence between top-down integrated assessment models and aggregation of bottom-up models. A main reason for this divergence is that place-based solutions and those that involve changing social norms and behavioral adaptations are hard to display in IAMs65. A plethora of country and city specific solutions, many of the categorized according to avoid and shift (ca. 15% and 18% of measures respectively), is estimated to have the potential to bring GHG emissions in the transport sector down to 2.5GtCO266. Key avoid strategies involve telecommuting, although total emission savings in land transport are estimated at not more than 1%67. For example, COVID-19 confinement induced telecommuting was compensated by more errands with cars, albeit at shorter distances in California30. Urban planning, street space rededication, smart logistical systems, and increased street connectivity with smaller distances have the largest potential to reduce need for travel68,69, with a counterfactual potential of 25% reduction in urban energy use in 2050 only considering newly built cities (repercussion effects in the building sector are included in this estimate)28. Improving transport nonetheless has the largest potential, in particular via electrification. In most ambitious transport energy models, a full electrification of land transport and power-to-fuels for aviation and shipping, can completely decarbonize the transport sector, while also decreasing primary energy required per unit of end use energy, in particular in electric land transport39. Vehicle leightweighting strategies can also lead to significant emissions savings through improved fuel economy70.
Avoiding energy use in buildings starts with smaller dwellings that reduce overall demand for lighting and space conditioning and smaller dwellings, shared housing, and building lifespan extension all reduce the overall demand for carbon-intensive building materials such as concrete and steel71,72. It also includes designing buildings based on bioclimatic principles to maximise energy demand reduction through nature and building typology (single-family homes versus multi-family buildings), adapting the size of buildings to the size of households redesigning both individual energy end use and building operations: replace artificial light with daylighting73,74 and use lighting sensors to avoid demand for lumens from artificial light; design passive houses using the thermal mass and smart controllers to avoid demand for space conditioning services16; eliminating standby power to reduce energy wasted in appliances/devices (this alone may reduce household energy use by 10%)75. 3D printing of buildings further reduces construction waste, optimizes the geometries and minimizes the materials content of structural elements76. Overall, ‘avoid’ potential in the building sector, reducing waste in superfluous floor space, heating and IT equipment, and energy use, is estimated at 10 and 30%, and possibly up to 50%77. Improve options, such as energy efficient appliances, insulation, and prosumer renewables on rooftops may similarly reduce GHG emissions, combined, by 50% [30-70%]16,78,79.
While demand-side solutions will change lifestyles, individuals have few opportunities to induce and realize demand-side solutions by themselves. Avoid measures require structural change in organization management (for example: working time models that enable teleworking), spatial structure (mixed use to increase accessibility with active modes), and incentives (taxing high floor space per capita to reduce wasteful resource use). Similar, shift solutions require the availability of new modes of service provision, e.g., by offering shared pooled mobility and high-quality plant-based diets, and regulation that prohibits high-emitting (and otherwise harmful) practices, such as intensive animal farming and instead promote low-carbon solutions, such as R&D spending for meat alternatives. Finally, improve options similarly require policy interventions, such as carbon pricing, banning inefficient heating systems, lightbulbs and cars with internal combustion engine and diesel motor, and mandating market shares of efficient technologies, planning procedures and practices.
Demand-side mitigation strategies improve wellbeing
Based on 406 papers (Table S3-S7), we analyze how sectoral demand-side and service-oriented mitigation strategies influence constituents of wellbeing. We systematically coded whether mitigation strategies for each sector have positive, neutral or negative impact on the 18 constituents of wellbeing introduced in Table S1. We performed expert judgement by a team of 2-4 researchers for each sector, also comprising explicit expertise on social sciences and wellbeing, and internally reviewed by at least 2 other researchers, to code impact in categories from -3 to +3 and substantiated judgement with evidence from the literature (Figure 2a). Confidence in judgement varied, because both scale and multitude of effects vary across the underlying literature. In other cases, literature was missing even when experts assumed relevant effects. Hence, we also provide confidence values, associated with each mitigation-strategy/wellbeing-constituent couple (Figure 2b) and report the confidence values also together with the results of the wellbeing evaluation below. The full table, including level of agreement and evidence and literature substantiating each entry is in the Appendix.
Demand-side mitigation strategies have positive impacts on human wellbeing (high confidence). Our study shows that among all demand-side option effects on wellbeing 76% (246 out of 324) are positive; 21.6% (70 out of 324) are neutral (or not relevant/specify); only 2.4% (8 out of 324) are negative. Active mobility (cycling and walking), efficient buildings and prosumer choices of renewable technologies have the most encompassing beneficial effects on wellbeing with no negative outcome detected. Urban and industry strategies are highly positive overall on wellbeing, but they will also reshape supply-side businesses with transient intermediate negative effects. Shared mobility, as all others, has overall highly beneficial effects on wellbeing, but also displays a few negative consequences, depending on implementation, such as a minor decrease of personal security for patrons of ridesourcing. Differentiation, however, is important. For example, shared pooled mobility provides more urban benefits, and also higher climate change mitigation potential, as compared to ridesourcing.
Positive outcomes on wellbeing are estimated to occur 19 times more often than negative outcomes in response to demand-side mitigation measures. Confidence is in 50% of all cases medium to high (between 3 and 5 on a scale from 0 to 5) but unequally distributed with higher confidence in the physical constituents than in the social constituents of wellbeing.
The highest benefits are observed in air, health and energy (all with high confidence level), food (medium confidence), mobility (high confidence), economic stability (high confidence), and water (medium-high confidence) respectively. Although the relation of demand-side mitigation strategies and the social aspects of human wellbeing is important, this has been less reflected in the literature so far, and hence our assessment finds more neutral/unknown interactions.
Wellbeing improvements are most notable in air quality (0.74 in average across all mitigation options on a scale from -1 to +1), health (0.72), and energy (0.68). These categories are also most substantiated in the literature, often under the framing of co-benefits. In many cases, co-benefits outweigh the mitigation benefits of specific GHG emission reduction strategies. This includes clean cook stoves (e.g., powered by LPG) that can improve livelihoods of more than 40% of the world population by reducing indoor air pollution80; it includes co-benefits from improved outdoor air quality in cities resulting from reduced private motorized mobility with combustion and diesel engines, and from more active mobility81,82, often associated with more accessible environment of compact cities83; and it includes a shift away from high-emission diets that would improve public health considerably, especially in high income countries84.
Food (0.51), mobility (0.46), and water (0.40) are further categories where wellbeing is improved. Only mobility has entries with highest wellbeing ranking for teleworking, compact cities, and urban system approaches. Effects on wellbeing in water and sanitation are mostly coming from building and urban solutions.
Social dimensions, such as communication, social protection, political stability and especially participation are less predominantly represented. An exception is economic stability (0.52), suggesting that demand-side options generate stable opportunities to participate in economic activities. Altogether, the literature on social constituents, in relationship to climate change mitigation, is meagre. However, there is still clear indication that many demand-side mitigation strategies have potential to improve also the social constituents of wellbeing. For example, the predominant contribution of clean cook stoves may relate to wellbeing of women, who require less time for biomass collection and cooking and can better participate in economic and social life85. Compact cities and urban system solutions have strong albeit ambiguous effects on wellbeing, and positive outcomes depend on urban design86,87.
Confidence is highest for the wellbeing dimensions air, health, and mobility, and for the mitigation options compact city, non-motorized transport and building –level sufficiency. The wellbeing dimensions education, shelter, and political stability have lowest confidence, also reflecting a respective scarcity in literature.
Table 2. Assuming preferences to be exogenous or endogenous has impact on the evaluation of solutions.
|
Supply-side solutions
|
Demand-side solution
|
Exogenous preferences
|
Current patterns of service provisions are appropriate and new technologies must substitute current supply-side technologies closely.
|
Making existing technologies more efficient (improve) are appropriate, but shifting or reducing consumption patterns are insufficiently considered. Social dynamics often directed to enable overconsumption.
|
Endogenous preferences
|
Lack of orientation on what should be produced; alternative (partially objective) metrics required.
|
Societies can choose to modify service provisioning systems and lifestyles; alternative metrics and institutions required.
|
Climate mitigation as if people matter
Our results matter for the core challenge of climate change mitigation. Even the most optimistic upscaling of low-carbon technologies, such as PV115, alone would be sufficient to meet currently projected energy demand in 2050, as approximately required by the Paris agreement. Demand-side reduction strategies hence provide essential breathing space needed for meeting climate targets in the short and medium term. They are also consistent with improved wellbeing, and more likely to protect non-climate planetary boundaries.
Further research on higher resolution on service provisioning systems that reduce GHG emissions while maintaining or improving constituents of wellbeing will be highly policy-relevant. A new configuration of work and service provisioning models consistent with low GHG emissions and resource demand can only be achieved by transitioning away from the current constellation of service provision models. This requires a paradigm shift in understanding that preferences of what constitutes a good life can change; it also necessitates a change of focus in modelling studies. Starting with a perspective on what people need for a good life adds compelling options to the space of climate change mitigation solutions.