Can you tell a green field from a cold steel rail? Examining the "green" of Green Infrastructure development

The rapid development of Green Infrastructure as an approach to planning has enabled landscape practitioners to implement a range of projects utilising its principles. Discussions though exist examining what Green Infrastructure is, how it should be planned, and whether it can be identified as only those elements of the landscape that are green. A further element of this argument examines the use of water within this process. Therefore, as planners, we can ask: can we tell a green field from a cold steel rail? Both may have a green or sustainable function with only the visual appearance differing. Debates, however, focus on practitioner selectivity of the interpretation of "green" infrastructure planning exploring whether physical landscape characteristics or the function of an investment is the main focus of discussion. Using the grey-green continuum developed by Davies et al. [2006. Green infrastructure planning guide project: Final report. Annfield Plain: NECF], this paper examines whether geographical differences exist in the application of the Green Infrastructure and examine how practitioners use the ambiguity of Green Infrastructure planning to guide investment. Drawing on academic and practitioner literature provides this paper with a balance of conceptual and process-based assessments evaluations of global Green Infrastructure focusing on the design and implementation of terrestrial and marine resources. This paper also examines whether the dominant landscape planning framework in each region could be considered contradictory to the wider application of Green Infrastructure principles.