Adapting to Climate Change: Urban Cities

Adapting to climate change is not only important in agricultural practices, but it is also important for urban cities to adapt as well. In this blog, I want to briefly introduce the different ways in which adaptive measures to climate change are adopted by comparing two case studies of two cities.

The first case study is Kampala city, this is the largest city in Uganda and it is expected to experience greater incidences of flooding as a result of climate change; flood-related problems such as pollution of water supplies, health risks and the spread of diseases are more likely to occur (Lwasa, 2010). Lwasa (2010) stresses the importance of identifying the impacts of climate change on urban populations, and subsequently determining the vulnerability of the urban population before attempting to apply adaptive measures. For example, in 2007, there were eight flood events and urban poor settlements such as Natete and Katwe were most vulnerable to these floods. This is because these settlements were informal and lacked the necessary infrastructure to withstand such floods. Hence, improving urban infrastructure, and addressing runoff and floods through building dams or planning crop cover to reduce storm flow are some adaptive measures that can be adopted. Other secondary impacts of the floods must not be ignored; worsening health conditions, economic damages and disrupted transport networks, and the overall lowering of the water table of Lake Victoria, can equally worsen livelihoods in many communities. Communities are willing to adapt but lack the means to do so, hence local and national governments must also be willing to take part in helping communities to adapt to climate change impacts. The Kampala City Council has an important role in governing the funds and allocation of resources, and the decision-making processes to adapting to climate change but cooperation with the community and their knowledge is also required to effectively increase the resilience of many communities to climate change impacts. Lwasa (2010) stresses the importance of understanding the context of urban cities and communities before choosing suitable adaptation strategies.

The second case study is Cape Town, South Africa, whereby water quantity, access and quality are the main problems that will occur because of climate change. Cape Town relies on surface and groundwater resources in the local area, however climate change scenarios such as an increase in average temperature by 1C by 2050 in Western Cape, or a general drying in most seasons in the south-eastern region of Western Cape can make these resources highly vulnerable (Ziervogal et al., 2010). Ziervogel et al. (2010) case study in Cape Town explains that while lower rainfall yields are a problem, the increasing demand for water due to population increases, poor wastewater management and underinvestment in infrastructure remains the largest problems and threats to water security in the city. To address these issues, climate change scenarios are incorporated into water management policies and planning, however, actors (communities, local governments, and national government actors) at all levels will need to agree that climate change adaptation is required and how it should be implemented. A combination of both supply and demand-side policies should be used; supply-side policies include building larger dams, improve water treatment processes, and exploiting other water resources, and demand-side policies include limiting water consumption and distribution. Ziervogel et al. (2010) noted that supply-side policies raised the cost of water and thus was too expensive for locals, and demand-side policies were more favourable and effective such that after the restrictions was imposed the demand for water reduced.

Adapting to climate change requires an understanding of the socio-economic background, and more specifically how climate change will have an impact on the urban city. The Kamapla case study saw the direct impacts of climate change on the city through floods and health-related impacts, which acted as a stronger incentive for adaptive measures. The Cape Town case study, however, experienced threats to their water supply through higher temperature and evapotranspiration rates, so it was more difficult to experience the impacts of climate change in the immediate term and this led to discussions about the priority of addressing and adapting to the impacts of climate change. This blog very briefly introduced how urban cities adapt to climate change through two examples but adaptation is much more complex than what was explained here, but I wanted to highlight the different factors and incentives that may govern the way an urban city would react to climate change. 

Adapting to Climate Change: Small-Scale Farmers

In my previous blog, I explored the impacts of climate change on agricultural farmers through the changes of rainfall and temperature across Africa. In the recent COP22 negotiations in Marrakech, agricultural adaptation to climate change was put at the forefront by 28 countries; Ban-Ki Moon explains that “Adaptation is not a luxury. It is a cautious investment in our future” (AAA, 2016a). A positive product of these negotiations saw the development of an initiative called the ‘Adaptation of African Agriculture (AAA) Initiative’ where the importance of climate change impacts on African agriculture is raised. This initiative focuses on implementing specific projects to improve Africa’s agriculture on all levels, ranging from soil management, agricultural water control, risk management and capacity building (AAA, 2016b). Perhaps, this negotiation can prove to be a pivotal point in elevating the concerns regarding agriculture and water availability. In this blog I want to explore the ways in which these farmers adapt to climate change, specifically exploring the small-scale farming techniques and adaptive measures to changing rainfall patterns and water availability for irrigation.

Rainwater Harvesting – Soil Moisture Conservation

This clip below provides a brief insight into the impacts of climate change and a farmers’ response to short rainfall, intense heat and the drying of soils through rainwater harvesting. 

Agriculture in many countries across Africa is highly dependent on rainwater and so climate change threatens a significant number of people’s livelihoods (Yosef & Asmamaw, 2015). Rainwater harvesting through storage in the soil profile is a form of in-situ water conservation whereby rainwater is held in the place that it falls. The amount of water stored in the soil is limited by the soil holding capacity and rate of infiltration, and in arid and semi-arid areas where coarse soils and high hydraulic conductivity, the amount of water stored in the soil is extremely limited and thus may not be a useful adaptive method (Yosef & Asmamaw, 2015). However, soil practices can be used to change the condition of the soil and thus improve the soil moisture retention. For example, in the drought affected areas of Ethiopia, stone bunds of 30cm wide and a height of 0.74m stone bunds are used to reduce runoff and soil erosion, and to increase soil moisture (Biazin et al., 2012). Other techniques such as terraces and trenches are also effective in increasing soil moisture and was widely adopted in traditional agricultural practices in many African countries. In Burkina Faso, the depth of soil pits was deepened and compost/manure was applied, this changed the composition of the soils, thus enabling the conservation of more water in the soil (Baizan et al., 2012). A study by Birru et al. (2012) found that farm yard manure and mulching significantly enhanced soil moisture retention. Soil moisture storage with mulch treatments of 6 ton ha^-1 of mulch retained 216.11mm of water, 39.15mm more water than soil without mulch treatment. 4 ton ha^-1 of straw mulch treatment retained 215.40mm of water, which is similar to the mulch treatment, thus showing that the straw mulch treatment has higher soil water retention capacities greater than mulch treatment.

Rainwater Harvesting – Macro-catchment

Larger rainwater harvesting techniques consists of collecting rainwater or runoff and diverting this water to a storage structure and target area through a macro-catchment system (Biazin et al., 2012). A study by Lebel et al. (2015) explains that rainwater harvesting techniques can prove to be a ‘valuable adaption strategy to climate change’, more specifically for maize crops because these techniques can address large issues concerning water deficits in the future. The study predicts that under RCP8.5 climate scenarios (highest greenhouse gas emissions during 2050s), maize yields have the potential to increase by 14-50% due to rainwater harvesting techniques meeting the demands required for productivity in Africa. Although, this study notes that in semi-arid and arid regions, rainwater harvesting techniques are unlikely to mitigate the impacts of intense temperatures and lack of rainfall, so other adaptive techniques are required.
An interesting study by Recha et al. (2015) suggested that the adoption of these rainwater harvesting techniques depended on the number of livelihood options available to small-scale farmers in Tharaka, Kenya. Farmers who depended on crops for their livelihoods was more likely to use rainwater harvesting techniques, but other attributes such as the cropland size during the MAM rainfall season, or the number of children per household also influenced the adoption of rainwater harvesting techniques. This shows that certain conditions would influence the choice of using these techniques by farmers, only if it would maximise their productivity and optimise the use of rainwater which would in turn improve their livelihoods.

Irrigation

Other adaptive strategies gaining momentum are irrigation schemes. Burney et al. (2013) argues that small scale distributed irrigation schemes, such as community level catchments, tubewells, sprinklers and drip lines, has five-times the cost-benefit than large centralised irrigation schemes such as dams. Yol et al. (2011) found that the internal rate of returns for large-scale irrigation schemes averages to 7% whereas small-scale irrigation schemes have a rate of 28%. This is because small-scale irrigation can benefit more from areas with high rainfall potentials, unlike large-scale irrigation which may have lower rainfall rates. Other benefits of small-scale irrigation include being able to adapt these schemes to local needs and thus maximise freshwater use for agriculture, whereby many small scale farmers can access this resource.

Concluding Thoughts

There are many adaptive strategies that small scale farmers can adopt to mitigate the impacts of climate change on their agriculturally based livelihoods, ranging from soil based moisture conservation (mulching, manure, terracing and trenches), macro-catchment rainwater harvesting and irrigation schemes. These techniques have been adopted in indigenous practices and have long been sustaining the African population. But given the onset of climate change and the devastating impacts that it is predicted to have over Africa, the COP22 negotiations can elevate the importance of adaptive strategies to a higher level, which may attract investment and development of these adaptive strategies and farmer’s adaptive capacities.