Decarbonisation of cities and regions is one challenge which needs to be addressed in order to achieve the Net Zero Target by 2050. In an interdisciplinary and transdisciplinary setting the Flagship DeCIRRA addresses the following questions: How might we decarbonise cities and regions? How might we make best use of local resources and existing infrastructure? What role can energy distributors and renewable gases play in theat transition towards an energy system without net-emissions of CO2? DeCIRRa is a platform bringing together practitioners from many sectors and will focus on critical aspects of sector coupling and relevant options of the production of renewables gases, including Power-to-Gas. Especially in the subproject led by ZHAW/Center for Energy and the Environment (CEE), different carbon capture and storage (CCS) and biological negative emissions options are being compared, as they will play an essential role in achieving the net zero target.