[论文解读] Estimating, monitoring and minimizing the travel footprint associated with the development of the Athena X-ray Integral Field Unit -- An on-line travel footprint calculator released to the science community

D. Barret|PubMed|Apr 12, 2020

Conferences and Exhibitions Management参考文献 1被引用 4

一句话总结

本文提出了一款开源的在线旅行足迹计算器，旨在估算、监测并最小化与爱达娜X射线积分场单元（X-IFU）项目相关的科研旅行所产生的碳排放。该工具采用七种不同的排放因子，量化了包括非CO2效应在内的CO2当量排放，使研究人员能够比较不同交通方式并选择低碳影响的会议地点。X-IFU项目的年碳足迹估计约为500吨CO2当量，主要来自联合体会议，通过视频会议和优化旅行规划得以减少。

ABSTRACT

Global warming imposes us to reflect on the way we carry research, embarking on the obligation to minimize the environmental impact of our research programs, with the reduction of our travel footprint being one of the easiest actions to implement, thanks to the advance of digital technology. The X-ray Integral Field Unit (X-IFU), the cryogenic spectrometer of the Athena space X-ray observatory of the European Space Agency will be developed by a large international consortium, currently involving 240 members, split over 13 countries, 11 in Europe, Japan and the United States. The travel footprint associated with the development of the X-IFU is to be minimized. For that purpose, a travel footprint calculator has been developed and released to the X-IFU consortium members. The calculator uses seven different emission factors and methods leading to estimates that differ by up to a factor of 5 for the same flying distance. These differences illustrate the lack of standards and regulations for computing the footprint of flight travels and are explained primarily, though partly, by different accounting of non- CO2 effects. When accounting for non-CO2 effects, the flight emission is estimated as a multiple of the direct CO2 emission from burning fuel, expressed in CO2-equivalent (CO2eq), with a multiplication factor ranging from 2 to 3. Considering or ignoring this multiplication factor is key when comparing alternative modes of transportation to flying. The calculator enables us to compute the travel footprint of a large set of travels and can help identify a meeting place that minimizes the overall travel footprint for a large set of possible city hosts, e.g. cities with large airports. The calculator also includes the option for a minimum distance above which flying is considered the most suitable transport option; below that chosen distance, the emission of train journeys are considered. To demonstrate its full capabilities, the calculator is first run on one of the largest scientific meetings; the fall meeting of the American Geoscience Union (AGU) gathering some 24000 participants and the four meetings of the lead authors of the working group I of the Intergovernmental Panel on Climate Change (IPCC) preparing its sixth assessment report. In both examples, the calculator is used to compute the location of the meetings that would minimize the travel footprint. Then, the travel footprint of a representative set of X-IFU related meetings is estimated to be 500 tons of CO2eq per year (to place this number in perspective, it is equivalent to 2 billion kilometers driven by an average passenger vehicle). Of this amount, each annual consortium meeting accounts for 100 tons, being located at a site of minimum emission and for a minimum distance for flying of 700 km. Actions to reduce the X-IFU travel footprint are being implemented, e.g., the number of large consortium meetings has been reduced to one per year and face-to-face working meetings are progressively replaced by video conferences. As the on-line travel footprint calculator may be used to all scientific collaborations and meetings, the calculator and its methodology described in this paper are made freely available to the science communitycommunity(https://travel-footprint-calculator.irap.omp.eu).

研究动机与目标

• 估算并监测X-IFU空间任务开发过程中国际科研旅行的碳足迹。
• 通过提供透明、标准化的旅行排放计算工具，最小化大规模科研合作的环境影响。
• 通过基于数据的会议地点和交通方式决策，支持科学界减少航空排放。
• 通过支持包括航空非CO2效应在内的CO2当量排放计算，促进可持续科研实践。
• 发布一个免费可访问的基于网络的工具，供更广泛的科学界使用，支持气候友好型国际会议规划。

提出的方法

• 该计算器使用七种不同的排放因子和方法，估算航空旅行的CO2当量排放，通过2至3倍的乘数考虑非CO2效应（如凝结尾迹和氮氧化物），从而实现对航空排放的全面评估。
• 引入最低飞行距离阈值（700公里），低于此距离时，系统将优先考虑铁路出行，依据为排放比较结果。
• 该工具通过汇总基于出发地-目的地配对及交通方式的个体旅行排放，计算一组参与者的总旅行足迹。
• 其内置优化引擎可系统性识别使所有参与者总旅行足迹最小化的会议主办城市。
• 该计算器以网页应用形式部署于 https://travel-footprint-calculator.irap.omp.eu，源代码和方法论已公开发布。
• 该系统已使用大型科学活动的真实数据进行验证，包括AGU秋季会议和IPCC工作组I领衔作者会议。

实验结果

研究问题

• RQ1 X-IFU项目的年度总旅行足迹是多少？其在会议和交通方式之间如何分布？
• RQ2 不同航空排放计算的排放因子和方法有何差异？导致估算值最高达五倍差异的原因是什么？
• RQ3 对于给定的一组参与者，哪个会议地点可使总旅行足迹最小化？如何系统性地计算该结果？
• RQ4 视频会议和旅行减少策略在多大程度上可降低大型科研合作的整体碳足迹？
• RQ5 如何一致地在旅行足迹计算中纳入航空的非CO2效应？其对总排放的影响如何？

主要发现

• X-IFU项目的年度旅行足迹估计约为500吨CO2当量，相当于在乘客车辆中行驶200万公里的排放量。
• 每次年度联合体会议的碳足迹约为100吨CO2当量，假设最低飞行距离为700公里，并采用最优主办城市选择。
• 计算器显示，排放估算值可能因所用方法不同而相差高达五倍，主要源于对非CO2效应（如凝结尾迹和臭氧生成）处理方式的差异。
• 与仅考虑CO2的计算相比，纳入非CO2效应可使排放估算值提高2至3倍，凸显了该校正方法在旅行规划中的重要性。
• 该工具成功识别出AGU秋季会议和IPCC工作组I会议的低碳足迹主办城市，证明了其在实际应用中的有效性。
• 通过将年度面对面会议限制为一次，并以视频会议替代面对面会议，项目已显著降低足迹，预计未来还将进一步减少。