طبقه بندی دقیق و اصول حسابداری کربنی برای شهرهای کم کربن و بدون کربن

A large number of communities, new developments, and regions aim to lower their carbon footprint and aspire to become “zero carbon” or “Carbon Neutral.” Yet there are neither clear definitions for the scope of emissions that such a label would address on an urban scale, nor is there a process for qualifying the carbon reduction claims. This paper addresses the question of how to define a zero carbon, Low Carbon, or Carbon Neutral urban development by proposing hierarchical emissions categories with three levels: Internal Emissions based on the geographical boundary, external emissions directly caused by core municipal activities, and internal or external emissions due to non-core activities. Each level implies a different carbon management strategy (eliminating, balancing, and minimizing, respectively) needed to meet a Net Zero Carbon designation. The trade-offs, implications, and difficulties of implementing carbon debt accounting based upon these definitions are further analyzed.

Cities in their current form are an evolved solution that increases societal wealth under resource constraints through ‘economies’ of scale, scope, and innovation. The deliberate design of the urban environment to accommodate constrained access to resources (e.g., electricity, vehicle fuel, food, durables, and consumables) has frequently been lacking, as evidenced by the masterplanned or organic growth cities of the past century. The scale and form of the urban environment has changed drastically with the availability of affordable and energy-dense resources moving from compact urban cores to extensive urban sprawl. However, as the majority of these resources depend directly or indirectly on climate-impacting and reserve-limited fossil fuels, the realization that resource access in the future may become markedly more constrained has led to a number of efforts to explicitly measure and mitigate the fossil-fuel dependence of the urban environment.