Urban and peri-urban agriculture in Goiânia: The search for solutions to adapt cities in the context of global climate change

Highlights

• Urban voids

• urban and peri-urban agriculture

• climate change

• carbon sequestration

Abstract

Goiânia is a city in the late 1930s, and one of the two cities constructedin the Brazilian savannah. In 2018, it had 1.4 million inhabitants and 2,05217 inhabitantsper km². With less than 100 years of age, the urbanization model associated with the effects of global climate change has led the city to live, in recent periods, with moments of water scarcity and flooding. In view of this, the urban municipal policy seeks to point out actions that aim to control land use and occupation from an environmental sustainability perspective. Urban and peri-urban agriculture (UPA) is one strategy and will be the main objective of this article. The urban municipal policy will indicate areas for the practice of UPA as a strategy for adapting cities in the context of climate change. As a secondary objective, the potential for carbon sequestration by this activity was analyzed. The methodology was based on the analysis of urban land use in a Geographic information system (GIS) environment. The database of the Municipality of Goiânia was used. The results indicated three levels of priorities, with a total of 10,650 hectares. In terms of carbon sequestration , this area would result in the capture of 5.536.764,60 tons of CO₂ from the atmosphere in 20 years.

Introduction

The Intergovernmental Panel on Climate Change (IPCC) estimates an average elevation of temperature on land between 2.6 to 4.8 °C by the end of the century if the current rate of greenhouse gas emissions is maintained (PBMC, 2016). Extreme weather events are designed and visualized on the globe with different effects on urban areas.

Although Brazilian cities are relatively new, changes in soil use and occupation patterns contribute to the change in local ecosystems, contributing, directly and indirectly, to the global climate changephenomenon In addition, such changes affect local weather-climate conditions, requiring local admininstrators to have a greater management capacity and technical knowledge.. Adaptation to the climate change scenario, as well as the construction of resilient cities has been an alternative pointed out in the scientific literature (Gonçalves, 2017). Resilience is defined as the ability of an ecosystem, population or species to recover after its initial condition has been perturbed (Holling, 1973)

The search for urban resilience remains a challenge in Goiânia. Between 2017 and 2019, the city revised its main normative framework of urban planning: the master plan, aiming at pointing out alternatives for environmental sustainability (PREFEITURA DE GOIÂNIA, 2018). Fifteen years earlier, the city presented its “Agenda 21” (PREFEITURA DE GOIÂNIA, 2004), which gave instructions on how to restructure and requalify urban areas, especifically along the water gutters. Although different urban planning projects were carried out during this period by the government, the city coexists with the urban sprawl, conurbation next to the adjacent municipalities and faces, in the metropolitan region, different moments of water scarcity (Hora and Salles, 2017).

Goiânia is a relatively new city and was designed and implemented in the late 1930s in the Brazilian savannah to be the new capital of the state of Goiás. Although recent, its urban growth and demographic was the result of migratory flows, which peaked between 1950 and 1990. This migratory process led to an unevenly constructed city, with emerging pockets of misery in the peripheral neighborhoods and irregular dwelings, especially in the valley edge of the capital. In 2018, Goiânia had a population of 1.4 million plus the population of the 21¹ municipalities that make up the metropolitan region, for a total of 2.4 million people. That is, over 1/3 of the state’s population is concentrated in 21 of the 246 municipalities in the State of Goiás (IBGE, 2010, IBGE, 2018).

The original planning of the city foresaw a network of parks and green areas. However, this has been compromised throughout its existence. The plumbing project of the water courses and the growing waterproofing of the urban mesh resulted in an increase in artificial drainage and in the compromise of the urban drainage system. In parallel, this growth resulted in the suppression of vegetation. Nascimento (2010) points out that the city's natural vegetation was reduced by 52.66% between 1986 and 2010, and the constructed are increased by 92.8% at the same time

Thus, becoming resilient and adapting to the current context, for Goiânia, means investing in urban drainage strategies and protecting the areas of water recharge., perspectives that integrate territorial management and, land-use patterns with emerging issues can point to innovative local and regional solutions. Urban and peri-urban agriculture (UPA) presents itself as a solution in this regard.

Urban and peri-urban agriculture can be understood as agriculture practiced within the urban perimeter or in the peripheries of this perimeter, in areas called periurban, where rural and urban activities are mixed and it is not possible to define the physical and social limits of these two spaces (Mougeot, 2005). It can be carried out by individuals, formal or informal organizations, and can take place either in public or private spaces.

According to Santandreu and Lovo (2007), the UPA contemplates multiple aspects: production (vegetable and vegetables, animal, inputs, and equipment), processing (processing and adding value), marketing; self-consumption; exchanges or donations; and the provision of service. The UPA allows for the control of land use, indicating new forms of use in the urban mesh, and can be an instrument against real estate speculation, as it develops in urban voids. Its practice helps to increase the permeability of the soil and createsmild microclimates by decreasing the temperature.

In addition to quantitatively and qualitatively corroborating environmental maintenance, UPA can become an important ally in carbon sequestration² and presents itself as a source of income, serving a portion of the population. Within the pillars of sustainability, pointed out by Sachs (2002), the UPA addresses spatial, social, economic and environmental (ecological) issues.

UPA practices cancontribute to lower temperatures, lower city densities and can also increase water percolation in line with the new global agreement to combat the effects of climate change, adopted at the 21st Conference of the Parties (COP -21), Climate Conference in Paris. The COP-21 reports predict that global warming will remain below 2 °C and stresses the importance of ensuring that the temperature rises on the ground does not exceed 1.5 ° C above pre-industrial levels (SUSTAINABLE CITIES PROGRAM, 2018, np.).

Even if human behavior changes, in an effort to prevent the increase in earth temperature from exceeding those indicated in the COP-21 reports, the GEO6 report (2019, p.44) clarifies that the world will experience “a certain level of warming compromised due to the past CO₂ emissions”. Therefore, it is a characteristic of climatic inertia. Climate change is related to CO₂ emissions that has been occurring since the Industrial Revolution period, over approximately 220 years, which represents an increase of 50% over the last40 years. In Brazil, there has only been an increase in CO₂ emissions after 1990 (GEO6, 2019).

Despite the pessimistic picture presented in GEO6, the fact is that human behavior has to change in the way we treat the environment. Even if climate inertia occurs for the next 25 years, (GEO6, 2019, p. 45 apud FIGUERES et al., 2017, p. 595) or if the CO₂ emission proposed by the paris agreement is not met, the temperature may still increase by 3 °C or more, causing natural disasters, such as polar ice melting level of water and creating an even greater environmental imbalance. Even if we guarantee sustainability in land use and land-use patterns, we must consider its restricted impact over the period of thermal inertia, since we will be under the influence of past emissions (GEO6, 2019, p.45). In this case, it is estimated that the temperature could be kept below 2°C.

UPA is an action that can contribute positively to the adaptation of the city to the climatic changes, due to the maintenance of permeable areas, control of land use of the soil, temperature decrease with the contribution of carbon sequestration, the balance of the hydrological cycle and contribution to a local microclimate amene.

In view of this scenario, the main objective of the study is to indicate areas for the practice of urban and peri-urban agriculture (UPA) integrated with the dynamics and territorial management as a form of social inclusion, production of healthy food, and mitigation of global warming in Goiânia. This action aims to provide municipal public management with information that can support the promotion of diversity,social and cultural inclusion. It also aims to cooperate with the provision of environmental services in a balanced and sustainable manner, and to contribute to improving the productivity of the city and food security of vulnerable groups. As a secondary objective, we sought to compute the carbon sequestration that would be provided if all the identified areas were entirely destined to the UPA.

The methodology used was based on the analysis of data in a Geographic Information System (GIS) environment using the projected land use and land-use patterns database of the Municipality of Goiânia and the legal references of the master Plan. As follows: i) survey of UPA experiences in Goiânia; ii) identification of the characteristics necessary for the implementation of the UPA, and application of these conditions in the mapping of the municipality of Goiânia; iii) establishment of criteria for prioritizing areas, their development, and application of criteria in a region of the municipality to validate the proposal; iv) note of guidelines for public policy of UPA in Goiânia to propose recommendations in the revision process of Law No. 171/2007 (Municipal Master Plan). For the secondary objective, the methodological proposal of an exploratory study for calculating carbon sequestration was considered and applied to the amount of area found in step ii, considering its total destination for UPA in a 20-year scenario.

To describe this, the article presented here is structured in 1. Introduction; 2.Urban and Peri-urban Agriculture in urban voids as an alternative to the territorial management of Goiânia; 3.Materials and methods, where 3.1.study area is presented, 3.2.Mental study map, 3.3.Normative Perspective 3.4.UPA experiences in Goiânia; 3.5. Necessary characteristics and their criteria for implementing the UPA, 3.6. Calculating carbon sequestration to reduce GEE emissions, 4. Results and Discussions with sub-items: 4.1. Selection and prioritization of areas for UPA in Goiânia, 4.2. Carbon sequestration in UPA practices, 4.3. UPA as an alternative to Goiânia and item 5. Final considerations.