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

Abstract

In this study, we analyze the effects of technology availability, political coordination, and behavioral change on transformation pathways toward net-zero greenhouse gas emissions in the European Union by 2050. We implemented an iterative stakeholder dialogue to co-design the scenarios that were calculated using a global multi-regional energy-economy-land-climate model. We find that in scenarios without behavioral change and with restriction of technologies, the target of greenhouse gas neutrality in the European Union cannot be reached. Already a target of 200 Mt CO₂eq/yr requires CO₂ prices above 100 €/tCO₂ in 2030 across all sectors in all scenarios. The required CO₂ price can increase to up to 450 €/tCO₂ by 2030 if technologies are constrained, if no complementary regulatory measures are implemented, and if changes in consumer behavior towards a more sustainable lifestyle do not materialize.

Fig. 1. Key characteristics of transformation scenarios.

a Annual greenhouse gas emissions and b carbon prices in the European Union for all five scenarios. Red colors represent the sector-oriented scenarios S1-S3, blue colors market-oriented scenarios S4-S5, with full (S3, S5) or restricted (S1, S2, S4) technology availability. See Table 1 for the description of scenarios S1-S5.

Fig. 2. Key trade-off for the technology and innovation dimension in the European Union.

a Cropland for bioenergy and b carbon capture and storage (values shown for 2050) increase, while c carbon price (values shown for 2030) decreases. We also indicate the respective values in 2020. Black arrows indicate the trade-off between limited vs. full technology availability for sector-oriented (S1 vs. S3) and market-oriented (S4 vs. S5) scenarios. See Table 1 for the description of scenarios S1-S5.

Fig. 3. Impacts of sector policies on the energy system in the European Union in 2020, 2030, and 2050.

a Licensed light duty vehicles by mode for all five scenarios. In the sector-oriented scenarios S1-S3 no new internal combustion engines (grey) are permitted after 2030, leading to a phase-out until 2050. b Final energy demand in the buildings sector by source, showing higher electrification (yellow) and phase-out of liquids (blue) and gases (grey) by 2050 in the sector-oriented scenarios S1-S3. c Electricity demand by sector and d fossil fuel use by source. Energy is given in exajoules per year. See Table 1 for a description of scenarios S1-S5.

Fig. 4. Impacts of behavioral changes on the land-use sector in the European Union.

a Land area in different land use pools in 2020 (cropland (brown) 114.5 million hectares (Mha), bioenergy areas (bright green) 0.7 Mha, pasture and rangeland (yellow) 65 Mha, other land (olive green) 69.4 Mha, forest (dark green) 163 Mha). b Change of land use in 2030 and 2050 and c Agricultural price index in 2030 and 2050 compared to 2020. See Table 1 for a description of scenarios S1-S5.

Fig. 5. Transformation indicators for all five scenarios.

The colored bars show a the CO₂ price in 2030, b carbon removal in 2050 (disaggregated into bioenergy with carbon capture and storage, re- and afforestation, and other), and c the percentage change between 2020 and 2030 for all other indicators except for the electricity price, where the change between 2020 and 2025 is shown as electricity prices peak in 2025. The colored dots show the percentage change between 2020 and 2050. See Table 1 for the description of scenarios S1–S5.