ABSTRACT

The Paris Agreement calls on countries to pursue efforts to limit global average temperature rise to 1.5°C. We derive a 2016–2050 emission budget for the EU Emissions Trading System (EU ETS) based on cost-effectiveness criteria aimed at achieving the 1.5°C target with a 50%–66% probability, and translate it into a cap reduction path. We show that, under current ETS parameters, the vast majority of this budget will be consumed by 2030. Meeting the budget under current 2030 EU ETS parameters would require drastic – and probably unrealistic – additional efforts after 2030. We derive a cost-effective scenario delivering a smoother and more credible emission pathway. We show that recently increased EU targets for renewable energy and energy efficiency, along with national coal phase-out policies up to 2030 provide cap adjustment potential. If the cap is adjusted to reflect these policies and if phased-out coal capacities are fully substituted through renewable energy, emissions in ETS sectors could decline by 57% through to 2030. This approximates our cost-effective scenario and translates into a linear reduction factor (LRF) for the cap of 3.6% for the period 2021–2030.

Key policy insights

• Paris Agreement-compatible emission budgets can serve as a guideline to define the minimum requirement for emission reductions in the EU ETS.

• The globally cost-effective emissions budget for EU ETS sectors in line with limiting global warming to 1.5°C is about 30 Gt CO₂e for 2016–2050.

• During the next decade the annual emissions cap must decrease much faster than currently planned to meet the cost-effective budget.

• Achieving a globally cost-effective emissions path requires that the linear reduction factor (LRF) of the EU ETS cap for 2021–2030 is raised from currently 2.2% to at least 4%.

• Incorporating EU targets for renewable energy and energy efficiency, as well as national coal phase-outs, enables an increase of the LRF for 2021–2030 to 3.6% without an additional abatement burden on EU ETS installations.

摘要

《巴黎协定》呼吁各国努力将全球平均气温上升限制在 1.5°C。我们根据旨在以 50%–66% 的概率实现 1.5°C 目标的成本效益标准，为欧盟排放交易体系 (EU ETS) 推导出 2016–2050 年排放预算，并将其转化为上限削减路径。我们表明，在当前的 ETS 参数下，该预算的绝大部分将在 2030 年消耗掉。在 2030 年之后满足当前的 2030 年欧盟 ETS 参数下的预算将需要付出巨大的——而且可能是不切实际的——额外的努力。我们推导出具有成本效益的情景提供更顺畅、更可靠的排放途径。我们表明，最近欧盟提高了可再生能源和能源效率的目标，以及到 2030 年的国家煤炭淘汰政策提供了上限调整的潜力。

关键政策见解

• 与《巴黎协定》兼容的排放预算可作为指南，用于定义 EU ETS 中减排的最低要求。

• 2016-2050 年，为了将全球变暖限制在 1.5°C，EU ETS 部门的全球具有成本效益的排放预算约为 30 Gt CO ₂ e。

• 在接下来的十年中，年度排放上限的下降速度必须比目前计划的要快得多，以满足具有成本效益的预算。

• 实现具有全球成本效益的排放路径需要将 2021-2030 年欧盟排放交易体系上限的线性减少因子 (LRF) 从目前的 2.2% 提高到至少 4%。

• 将欧盟关于可再生能源和能源效率的目标以及国家煤炭淘汰目标纳入其中，可以将 2021-2030 年的 LRF 增加到 3.6%，而不会对 EU ETS 装置造成额外的减排负担。