Transportation of Carbon Dioxide (CO 2 ) via high-pressure pipelines from source to storage site forms an important link in the Carbon Capture and Storage (CCS)chain. To ensure the safety of the operation, it is necessary to develop a comprehensive understanding of the consequences of possible pipeline failure. CO 2 is a hazardous substance and an accidental release may lead to catastrophic damage. This paper describes an experimental investigation of the dispersion of CO 2 in the atmosphere in a full-scale burst test of a pipeline containing high-pressure dense phase CO 2 . The experiment was carried out to simulate a CO 2 pipeline failure in the real world. The test rig consisted of a buried 85 m long, 610 mm diameter pipeline test section connected at either end to 116 m long reservoirs. An explosive charge detonated at test section half-length initiated a rupture in the pipe wall top surface, releasing the high-pressure contents. The atmospheric dispersion of the CO 2 following the explosive release was measured. The paper also describes Computational Fluid Dynamics (CFD)simulations of the dispersion of CO 2 following the release. The CFD models were validated against the experimental data. The models were then extended to estimate the consequence distances related to CO 2 dispersion following failure of longer pipelines of various diameters under different wind speeds and directions. Comparison of the results with prior studies was carried out.