Technology availability, sector policies and behavioral change are complementary strategies for achieving net-zero emissions

The study is motivated by the need to achieve the European Union’s goal of net‑zero greenhouse gas emissions by 2050 within the broader context of global pathways consistent with limiting warming to 1.5 °C. The IPCC AR6 highlights that most 1.5 °C pathways rely on multi‑sectoral approaches. The EU has adopted the European Green Deal and a long-term strategy targeting net‑zero GHG emissions by 2050, yet the design and implementation of effective policy measures remain debated across member states. Technology availability (e.g., CCS, nuclear, wind, bioenergy) depends on social acceptance and political feasibility; policy instruments range from carbon pricing to bans, standards, and subsidies; and consumer behavior may or may not shift toward more sustainable choices. Existing literature has extensively examined technology options, but comprehensive analyses that jointly consider technology availability, policy coordination, and behavioral change across sectors are scarce. This study addresses that gap by co‑developing with stakeholders a coherent set of narratives and scenarios that combine these three dimensions and by quantifying their implications for achieving the EU’s climate targets.

The paper situates itself within findings from the IPCC AR6 on mitigation pathways and EU-focused energy system studies that examine the role of technology portfolios and policy instruments. Prior research has extensively analyzed impacts of technology options such as CCS, renewables, and nuclear on mitigation strategies, and the role of carbon pricing and sector policies (e.g., EU ETS tightening). However, there is comparatively less work on the combined and cross-sector interplay of technology availability, policy coordination, and behavioral change including demand-side measures (e.g., modal shifts, dietary change). The authors build on these strands, integrating them into a single scenario framework co-produced with stakeholders to evaluate their complementarities and trade-offs for achieving net-zero GHG emissions in the EU.

The study uses an iterative stakeholder dialogue to co-design five transformation narratives that combine three scenario dimensions: (i) technology and innovation (full availability of mitigation options with a focus on GHG mitigation vs restricted set emphasizing social acceptance, limiting CCS, nuclear, wind, and bioenergy), (ii) political coordination (market-oriented relying mainly on an economy-wide CO₂ price vs sector-oriented where carbon pricing is complemented with targeted sector policies such as bans on internal combustion engines or fossil heating and proxy subsidies for electricity or hydrogen), and (iii) behavioral change (price-oriented behavior with responses driven by price signals vs value-oriented behavior reflecting broad societal shifts to sustainable consumption, modal shifts, and dietary changes). From these dimensions, five scenarios (S1–S5) were derived: policy steering approach (S1), behavior-oriented approach (S2), technology-oriented approach (S3), acceptance-oriented approach (S4), and market economy approach (S5). Scenarios aim to be globally consistent with a 1.5 °C limit and to meet EU net‑zero GHG by 2050. Modeling framework: The integrated assessment model REMIND-MaGPIE is used. REMIND (v2.2, open-source) is a multi-regional intertemporal general equilibrium energy-economy-climate model with detailed energy system representation and technology pathways, including CO₂ capture, utilization and storage, and CDR options (BECCS, DACCS). MaGPIE (v4.3.2, open-source) is a global land-use model that optimizes land allocation under socio-economic and biophysical constraints, representing cropland, forest, pasture, other land, and associated AFOLU emissions (CO₂, CH₄, N₂O). REMIND and MaGPIE are soft-linked iteratively to equilibrate bioenergy supply-demand and land-use emissions under climate policy constraints; REMIND provides emissions profiles and bioenergy demand, MaGPIE returns land-use emissions and bioenergy prices; REMIND’s bioenergy supply curves are updated accordingly. Scenario implementation: Sector policies include explicit/implicit measures such as bans on ICE sales for LDVs after 2030, phase-out of fossil heating, and proxy subsidies affecting uptake of electrification and hydrogen. Behavioral changes include reduced energy demands, modal shifts, and dietary shifts toward healthier, less animal-based diets consistent with EAT-Lancet guidance. Bioenergy imports into the EU are disallowed to avoid induced land-use change emissions. Carbon prices are regionally differentiated; beyond carbon pricing, additional measures are applied in the EU only to ensure comparability. The scenarios consider strong near-term ambition (2030 milestones) and track implications for energy, land, and economy-wide indicators. System boundaries and limitations: REMIND represents the EU27+UK as one aggregate region; country-level dynamics are not resolved. Trade of secondary/useful energy carriers (e.g., hydrogen imports) is not reported; in scenarios Europe cannot import hydrogen and cannot import bioenergy. Policies implemented in the EU are assumed not to induce feedback responses in other regions. MaGPIE does not include peatland and soil carbon management or organic farming and excludes some land degradation feedbacks. The model assumes first-best policy settings without market failures, and technology cost uncertainties remain, particularly for emerging CDR options.

- Across all five scenarios, EU GHG emissions decline rapidly from the outset, but scenarios lacking behavioral change and restricting technologies (price-oriented behavior with social-acceptance constraints) cannot reach GHG neutrality by 2050; for comparability, a relaxed target of 200 Mt CO₂/yr residual emissions in 2030 is used for such cases, requiring offset by CDR. - CO₂ prices needed in 2030 span a wide range depending on technology availability, sector policies, and behavior: approximately 125 €2020/tCO₂ (with full technology and sector policies) to more than 450 €2020/tCO₂ (market-oriented, restricted technologies; S4). Sector-oriented scenarios (S1–S3) consistently achieve lower CO₂ prices than market-oriented ones (S4–S5). In S1, targeted policies yield about 170 €2020/tCO₂; augmenting S1 with either full technology availability (S3) or value-oriented behavior (S2) reduces prices by roughly 25–35% to around 125 and 109 €2020/tCO₂, respectively. - Restricting socially contentious technologies (notably CCS and bioenergy) increases CO₂ prices and reliance on more expensive abatement. The carbon price increase from allowing full to restricted technology sets is larger in market-oriented cases (135%: 194 → 456 €2020/tCO₂, S5 vs S4) than in sector-oriented ones (36%: 125 → 170 €2020/tCO₂, S3 vs S1), because sector policies already reduce residual emissions and CDR needs. - Targeted sector policies accelerate direct electrification: banning new ICE LDVs after 2030 results in near-complete electrification of LDVs by 2050; such uptake is not achieved with carbon pricing alone even at >450 €2020/tCO₂ by 2030. - Behavioral changes have consistently positive impacts: they lower necessary CO₂ prices, reduce non-CO₂ residuals, decrease energy demand and consumer prices, and yield environmental and health co-benefits, thereby lowering reliance on CDR. - None of the scenarios achieves the target without CDR. Residual emissions in 2050 are in the range of 740–1180 MtCO₂eq/yr and must be balanced by CDR, including about 200 Mt CO₂/yr residual emissions that remain uncompensated in the main scenarios. If CCS/CDR is limited, deeper residual emission cuts (e.g., via lifestyle change) are required; without both CDR and behavioral cuts, GHG neutrality is unattainable. - To meet the climate target with CO₂ prices near or just above 100 €2020/tCO₂ by 2030, the EU must either allow technologies with limited social acceptance (e.g., CCS), implement strong sector policies (bans/standards), or enable broad behavioral change; absent these, CO₂ prices exceeding 450 €2020/tCO₂ by 2030 are required. - The technology-acceptance trade-off entails higher CCS deployment and larger land areas for bioenergy (when allowed) versus substantially higher CO₂ prices (when restricted). Bioenergy imports are disallowed, so EU bioenergy must be met domestically, affecting land allocation.

The findings demonstrate that technology availability, sector policies, and behavioral change are complementary levers for achieving net-zero GHG emissions in the EU. Relying on carbon pricing alone becomes prohibitively expensive when socially contentious technologies are restricted and when behavioral shifts do not materialize. Targeted sector policies materially reduce CO₂ price requirements by accelerating technology diffusion (e.g., electrification of transport and buildings), thereby cutting residual emissions and reducing CDR dependence. Allowing CCS and bioenergy broadens mitigation pathways, lowering economy-wide costs but increasing deployment of CCS and bioenergy land needs; the associated social acceptance and environmental trade-offs must be managed. Behavioral changes deliver system-wide benefits—lower prices, reduced energy demand, and non-CO₂ reductions—mitigating the need for high CO₂ prices and for CDR. Distributional implications of high CO₂ prices can be significant for low-income households, underscoring the importance of revenue recycling and complementary social policies. Overall, the results argue for coordinated action: enabling key technologies where socially acceptable, implementing effective sector policies to address market failures and deployment barriers, and fostering structural conditions that support low‑carbon consumption choices, thereby minimizing both costs and CDR reliance.

The study contributes an integrated, stakeholder co-designed scenario set that jointly examines technology availability, political coordination, and behavioral change for EU net‑zero by 2050 using the coupled REMIND–MaGPIE framework. It shows that GHG neutrality cannot be achieved without CDR, and that at least one of the following is required to keep 2030 CO₂ prices near or moderately above 100 €2020/tCO₂: allowing technologies with limited social acceptance (e.g., CCS), adopting strong sector policies (e.g., bans on ICE sales and fossil heating), or realizing broad behavioral shifts toward sustainable consumption. If none occurs, prices exceed 450 €2020/tCO₂ by 2030. The analysis underscores the trade-offs between CCS/bioenergy deployment and carbon price levels, and highlights the positive system-wide effects of behavioral change. Future research should quantify the full economic costs of sector regulatory policies and compare them to the welfare and distributional outcomes of higher carbon pricing, and further explore social acceptance dynamics and uncertainties in technology costs, especially for CDR.

Modeling limitations include: (i) first-best optimization assumptions without explicit market failures, implying modeled CO₂ prices may differ from real-world price instruments; (ii) uncertainties in future technology costs, especially for emerging CDR options; (iii) spatial aggregation of the EU27+UK into a single region in REMIND and MaGPIE, precluding country-level dynamics; (iv) constrained trade assumptions—no bioenergy imports and no reported trade of secondary/useful energy carriers (e.g., limited treatment of hydrogen imports); (v) EU policies are assumed not to induce policy responses elsewhere; (vi) MaGPIE omits certain mitigation options and feedbacks (e.g., peatland and soil carbon management, organic farming, some land degradation processes). These constraints may affect the generalizability and precise quantitative outcomes, including land-use and price responses.