Managing CO2 under global and country-specific net-zero emissions targets in Europe

TL;DR

This study uses a detailed energy system model to compare the impacts of EU-wide versus country-specific net-zero CO2 targets, revealing differences in costs, CO2 prices, and infrastructure needs.

Contribution

It introduces a high-resolution, network-aware model to analyze the effects of different net-zero strategies across Europe, filling gaps in previous coarse or global-only models.

Findings

Country-specific targets increase system costs by 1.4%.

Significant cross-border CO2 transport occurs in both scenarios.

Different strategies influence investment in direct air capture and renewables.

Abstract

The European Union (EU) aims to reach carbon neutrality by 2050. This requires capturing CO2, eventually transporting it to different regions, and either converting it into valuable products or sequestering it underground. Although the target is set for the entire EU, in practice, most of the governance and strategy to attain it remains in the individual member states. Previous literature modelling how Europe can achieve carbon neutrality has either considered only a global CO2 limit or used coarse spatial and temporal representation without proper network modelling. Here, we use a highly-resolved open model of the European sector-coupled energy system, PyPSA-Eur, to explore the impacts of imposing net-zero emissions globally for the entire EU versus imposing carbon neutrality for each country. Forcing net-zero emissions in every country increases system cost by 1.4%, demands varied CO2 prices, and triggers higher investment in direct air capture and renewable capacities. Furthermore, in both scenarios, a significant portion of the captured CO2 is transported across Europe, either directly via CO2 pipelines or indirectly via solid biomass or synthetic methane gas, methanol, and oil. Our research enables quantifying the impact of following a collaborative or self-sufficient carbon management strategy to attain carbon neutrality.