The aviation industry is one of the fastest-growing sectors in producing carbon emissions. In order to reduce its carbon footprint and to respond to the increasing number of people concerned about the impact caused by air transport on climate change, the International Civil Aviation Organization (ICAO) has recently passed the “carbon neutral growth from 2020” resolution requiring that the global net CO₂ emissions from international aviation do not exceed the 2019–2020 levels. Airlines, however, can act beyond their obligations under the ICAO resolution investing in projects aimed at reducing or offsetting all the emissions produced not only by their international flights but also by their domestic flights. The aim of this paper is to test whether Italian air travellers would be willing to donate a contribution to finance these projects and whether the willingness to pay depends on the projects’ type and on the projects’ effectiveness. To this aim we performed a stated-choice experiment involving a sample of 1228 Italians who travelled by plane at least once in the last 3 years. We find that their willingness to pay ranges from €12 to €38 per ton and from €14 to €66 per flight. The description of the project type to be financed via the passengers’ donations is one of the most important factors influencing their willingness to pay. Other key factors are the quantity of CO₂ reduced or offset via the project and the respondents’ gender, education degree, occupational status, environmental consciousness and travel habits. Our results are useful for airlines to design the donation proposals and improve the corporate image and for policy makers to support air travellers’ environmental conscious behaviour and airlines’ environmental sustainable strategies.

航空业是产生碳排放量增长最快的行业之一。为了减少其碳足迹并应对越来越多的人担心航空运输对气候变化的影响，国际民航组织（ICAO）最近通过了“ 2020年碳中和增长”决议，要求全球净CO ₂国际航空的排放量不超过2019–2020年的水平。但是，航空公司可以超出国际民航组织决议规定的义务行事，投资于旨在减少或抵消国际航班以及国内航班产生的所有排放的项目。本文的目的是检验意大利航空旅行者是否愿意为这些项目捐款，以及支付意愿是否取决于项目的类型和项目的有效性。为此，我们进行了一项陈述选择的实验，涉及1228名在过去3年中至少乘飞机旅行过一次的意大利人的样本。我们发现他们的支付意愿为每吨12欧元至38欧元，每次航班14欧元至66欧元。通过乘客的捐赠来资助的项目类型的描述是影响其支付意愿的最重要因素之一。其他关键因素是一氧化碳的数量₂通过项目和受访者的性别，教育程度，职业状况，环境意识和旅行习惯而减少或抵消。我们的研究结果对于航空公司设计捐赠提案和改善企业形象以及决策者支持旅行者的环保意识行为和航空公司的环境可持续战略都是有用的。