Emissions savings from equitable energy demand reduction

The paper addresses how to reduce energy demand in the Global North in ways that are equitable and compatible with climate justice. While demand-side strategies could deliver 40–70% of global emissions reductions by 2050, equity principles imply that those who have contributed most to climate change and have the greatest capacity should reduce most, while ensuring that everyone can satisfy basic needs. Concepts such as consumption corridors, the safe and just space of humanity, and a good life within planetary boundaries suggest setting minimum and maximum consumption thresholds to meet needs within ecological limits. A key gap identified is that the emissions impacts of equitable EDR—reducing high-end energy consumption while allowing increases for those with unmet needs—had not been assessed. The study aims to quantify these emissions effects across 27 European countries and to evaluate their contribution to meeting globally equitable carbon budgets.

The literature on energy and climate justice emphasizes principles of historical responsibility, capacity to act, and universal needs satisfaction. Frameworks including consumption corridors, the safe and just space, and living well within planetary boundaries advocate defining democratically negotiated lower and upper bounds for consumption to meet needs without breaching ecological limits. Prior quantitative work has estimated energy needed to meet basic needs and wellbeing and suggested that eradicating global energy poverty could raise energy use by about 7%, offsettable by a 15% reduction among above-average consumers. Research also shows high inequality in energy use, especially for travel, and diminishing wellbeing returns at high consumption levels. However, the specific emissions savings from simultaneously capping high users and raising low users to meet needs had not been quantified prior to this study.

The study uses a microsimulation approach on representative Household Budget Survey (HBS) microdata for 27 European countries (EU pre-Brexit minus Austria), using 2015 data for 23 countries and 2010 data for Malta, Portugal, Slovenia, and the United Kingdom (total sample n=275,614 households). Household expenditures are mapped to energy use (GJ) and greenhouse gas emissions (CO2e) via country- and category-specific conversion factors derived from the multi-regional input–output database Exiobase 3.7, using net energy and GWP100. Domains include home energy, travel, food, and other consumption, summed to total. Per capita values are used (household estimates divided by household size with person-based weights). To address infrequency-of-purchase and outliers, observations at or below zero and the top/bottom 1% in energy/emissions and income are excluded where relevant. Equitable EDR is modeled by replacing, within each country and domain: (a) energy use by the top 10% and top 20% of consumers with the 90th and 80th percentile levels, respectively; and (b) a poverty uplift where the bottom 20% of energy consumers who are in income poverty (equivalized income <60% of national median) are raised to the 20th percentile of energy use. An additional scenario reduces all above-mean energy use to the mean (affecting ~42% of households). Emissions changes are computed by reassigning emissions of the 90th/80th percentile (or mean) to those above these thresholds, summing by country and domain, and comparing to original totals. Three 2020–2050 scenarios assess compatibility with globally equitable budgets: (1) a one-off 2020 reduction among high users with a 1.4% annual emissions decline thereafter; (2) as (1) plus an extra 10% reduction among high users every five years; and (3) variable annual reduction rates that achieve Europe’s equal-per-capita (EPC) share of a 500 GtCO2e global budget (35 GtCO2e) and an adjusted Greenhouse Development Rights (GDR) budget (15.1 GtCO2e), with and without high-user caps. Logistic regressions (average marginal effects) identify sociodemographic correlates of belonging to the top 10%/20% of per capita energy consumers. Finally, four deliberative workshops (England, 2021; total n=31) sampled participants across combinations of high/low domestic and travel energy use to explore public perceptions of equitable EDR policies; transcripts were thematically analyzed in NVivo.

• Energy inequality is high, especially for travel (Gini coefficients: total 0.29; home 0.41; food 0.32; travel 0.47; other 0.35). The top 20% account for 47.5% of travel energy use; the bottom 50% account for 20.4%.
• Capping high users delivers substantial reductions: • Top 10% reduced to 90th percentile: −4.4% total emissions, −6.0% domestic energy, −8.3% travel across 27 countries. • Top 20% reduced to 80th percentile: −9.7% total, −11.4% home, −16.8% travel. In energy terms, reductions correspond to around −5.4 EJ total, −1.6 EJ home, and −2.3 EJ travel. • Reducing above-mean users to the mean: −22.1% total, −24.2% home, −40.5% travel.
• Poverty uplift (raising bottom 20% of energy users in poverty to the 20th percentile) slightly increases emissions by about +1.4% total, +1.2% home, and +0.9% travel, but combined with high-end caps still yields net reductions (e.g., with top 20% cap: −8.3% total, −10.2% domestic, −15.8% travel).
• Budget compatibility: With a historic 1.4% annual reduction, all pathways in scenarios (1) and (2) exceed EPC and GDR budgets before 2050. For example, with a top-quintile cap to the 80th percentile and an additional 10% cut every five years, the EPC budget is exhausted by ~2031.
• Required annual reductions to meet budgets (scenario 3): • No top-level cap: 9.9%/year (EPC) and 24.0%/year (GDR). • Top 20% to 80th percentile: 8.78%/year (EPC) and 21.7%/year (GDR). • Above-mean to mean: 7.29%/year (EPC) and 18.6%/year (GDR); adding an extra 20% reduction from above-mean users by 2025 lowers the GDR-required annual rate to 12.5%. • Poverty uplift changes required annual rates by only ~0.1–0.3 percentage points.
• Household correlates of high energy use (top 20%, total energy, average marginal effects): higher income strongly increases likelihood (4th quintile +19 pp; top quintile +41 pp). Higher education (+3 pp) and employment (+3 pp) also increase likelihood; more adults (−8 pp), children present (−18 pp), and urban residence (−2 pp) decrease it. Older/retired households are more likely high domestic energy users but less likely high travel users.

The study shows that equitable EDR strategies—capping high-end energy use while safeguarding needs for low users—can deliver significant emissions reductions, particularly in travel, where inequality and emissions intensity per euro are highest. Increasing consumption for low-income, low-energy households has only marginal effects on aggregate emissions, indicating that needs-focused equity can coexist with meaningful reductions. However, such strategies alone are insufficient for Europe to stay within globally equitable EPC or GDR carbon budgets; very high annual reductions are still required, implying concurrent systemic decarbonization and broader demand reductions. Equity-targeted measures may enhance social legitimacy and acceptance by aligning effort with responsibility and capacity. Deliberative workshops suggest the public may support restrictions on luxury/high energy use, especially where low-carbon alternatives exist and when allowances for differential needs are included, though concerns about freedom and blanket rations persist.

Targeting high-energy users offers sizable, immediately realizable emissions reductions in Europe and aligns with climate justice by placing greater responsibility on those with higher contributions and capacities, while enabling needs satisfaction for low users. Yet, to remain within globally equitable carbon budgets, Europe must also enact steep annual emissions cuts alongside technological decarbonization and structural changes. Policy design that combines caps, fair allowances, and provision of low-carbon options, together with careful framing around justice and co-benefits, can bolster public acceptance. Future research should investigate political and societal pathways to achieve the large, rapid demand reductions required under stringent equity-based budgets (e.g., scenario 3), and refine participatory processes for democratically setting consumption thresholds.

Limitations stem from HBS data quality and methodology: cross-country differences in data collection and short expenditure diary windows cause infrequency-of-purchase issues and false zeros; the analysis excludes observations at/below zero and the top/bottom 1% to reduce skew, which may affect representativeness. Mapping expenditures to energy/emissions via MRIO factors introduces uncertainty from price-level differences and sectoral aggregation. Scenario analyses assume fixed or stylized annual reduction rates and do not endogenously model technological change or future shifts in emissions intensity, which affects the translation from energy use to emissions. Thresholds for high/low energy users (top/bottom 10–20%, mean) are illustrative and not prescriptive; real-world thresholds should be democratically determined and may differ by context.