Cloud computing has become the de facto paradigm for delivering software to system users, with organizations and enterprises of all sizes making use of cloud services in some way. On the surface, adopting the cloud appears to be a very efficient approach for offloading concerns such as infrastructure management, logistics, and most importantly for this work, energy consumption and consequent carbon emissions to the cloud service provider. However, this is in many ways not an appropriately accountable solution to managing the contribution of the ICT sector to global emissions. To this effect, in this paper we report on an exploratory case study done in collaboration with a Software as a Service provider operating globally in the telecommunications sector. The study reckons with the service provider using multi-tenant, that is, shared, off-premises data centers for hosting their private cloud infrastructure towards developing a fair model of allocating operational emissions among the service tenants -- customer companies with many distinct users. The developed emissions model has to account for allocating in an appropriate manner the generated emissions between the tenants of the software provider services, and among the different tenants of the same data center. A carbon footprint report generator is developed building on the proposed model which is, in turn, used to present sustainability reports to involved stakeholders for evaluation purposes. Our results show that the model is perceived as transparent, informative, and fair, with requested improvements focusing mainly on the generated reports and the information contained therein.

翻译：云计算已成为向系统用户交付软件的事实标准，各类规模的组织和企业均以某种形式采用云服务。表面看来，采用云计算似乎是将基础设施管理、物流，以及对本研究至关重要的能耗与碳排放等问题转移给云服务提供商的极为高效的方式。然而，从多个层面来看，这并非一种能够恰当问责的管理信息通信技术部门对全球碳排放贡献的解决方案。为此，本文报告了一项与一家在全球电信领域运营的软件即服务提供商合作开展的探索性案例研究。该研究审视了该服务提供商使用多租户（即共享）异地数据中心托管其私有云基础设施的情况，旨在构建一个在服务租户（即拥有众多不同用户的客户企业）之间公平分配运营碳排放的模型。所开发的碳排放模型必须恰当地将产生的碳排放归因于软件提供商服务的各租户之间，以及同一数据中心内的不同租户之间。基于所提出模型，我们开发了一个碳足迹报告生成器，进而用于向相关利益相关方展示可持续发展报告以供评估。研究结果表明，该模型被视为透明、信息丰富且公平的，所要求的改进主要集中于生成的报告及其所含信息。