Abstract:
Rapid urbanisation worldwide since the 1950’s has led to the depletion of ecosystem carbon pools and a loss of biodiversity, particularly in the urban environment. Urban expansion not only possess many threats to human well-being but also a greater over-arching threat of global climate change. South Africa has a heavy dependence on fossil fuel burning power stations, which ranks it as the fourteenth highest carbon emitter in the world. On top of this, current agricultural practices are detrimental to the environment, lead to lower yields and are a large contributor to South Africa’s national carbon emissions. These unsustainable practices also fail to resolve urban food security, an emerging concern in the City of Tshwane.
The United Nations Framework Convention on Climate Change (UNFCCC) gave rise to the 2015 Paris Agreement dealing with greenhouse gas emissions mitigation, adaption and finance. Although South Africa signed the agreement pledging the reduction of national carbon emissions by the year 2035, the current trajectory will not honour this pledge.
The historical landmark of Pretoria West Power Station, a vastly underutilised landscape that has the potential to offset its past transgressions in terms of its impact on the atmosphere, is the focus area for the study. This dissertation investigates and proposed a new approach to the urban productive landscape in the form of a Carbon Farm, through: 1) Effective methods of carbon sequestration, including the mechanisms to aid this; 2) design principles which combat biodiversity loss in the urban environment; 3) design principles for climate change adaption and; 4) how these principles can be combined to form a landscape which addresses human well-being, food security and the rehabilitation of an industrial site.
The Carbon Farm challenges the way industrial landscapes are viewed, from a highly polluted landscape which should be situated on the outskirts of cities, to a landscape which is efficient, clean and attractive to a general populace whilst ensuring that emissions created are absorbed in-situ.
It achieves this using a multi-layered approach inspired by the three-step process of carbon sequestration as a conceptual driver. This is to ensure that the design of the Carbon Farm can facilitate the required levels of production in the form of forestry, agroforestry and algae farming whilst still contributing to human and environmental well-being. The human experience is further enhanced through the addition of a skywalk which takes the user on an elevated journey over the landscape to experience each carbon sequestration method prevalent in the Carbon Farm. This journey then culminates within an existing cooling tower where the user is able to take in the sheer scale and magnitude of the infrastructure used to generate electricity.
