City to city learning and knowledge exchange for climate resilience in southern Africa

ground of projects and efforts to deal with the potential challenges that were identified. The anticipation that climate change could undermine development efforts and exacerbate the plight of the city’s most vulnerable residents in informal settlements gave the eThekwini Municipality the impetus for innovative adaptation efforts. More recently, the city has been hit by a series of floods which has exposed its infrastructure and more so the informal settlements. City learning points The multiple stressor context and interconnectedness of the urban ecosystem across the four study cities of Harare, Windhoek, Lusaka and Durban was demonstrated well by presenting similarities and differences (see Tables 3 and 4). We present the learning points in five emerg- ing thematic areas, namely water and waste, energy, informal settlements, water governance and city climate integration and planning. Water and waste issues. As a learning point, the City of Windhoek (CoW) is implement- ing efficient water conservation measures, which are linked to several factors and actions that form part of the city’s water ecosystem. These factors include climate (droughts), raw water availability, water scarcity and/or availability of water from remote catchment areas. The city deals with water scarcity through several initiatives such as wastewater reclamation and desali- nization (although this is not a specific CoW initiative), artificial recharge of aquifers, water rationing and awareness campaigns to change water use behavior e.g. changing gardens by Table 3. Similarities across the study cities.

Similarities Cities Income groups determined levels of risks and vulnerabilities Durban, Harare, Lusaka, Windhoek Multiple stressor context; climatic and non-climatic risks High levels of informal settlements Durban, Lusaka, Windhoek Droughts Harare, Lusaka, Windhoek Flooding Durban, Lusaka, Harare Unpredictable rainfall patterns Harare, Lusaka, Windhoek Low quality and inadequate potable water supply and solid waste disposal; unregulated water abstraction Harare and Lusaka Comparable renewable energy efforts Harare and Windhoek https://doi.org/10.1371/journal.pone.0227915.t003 Table 4. Differences across the study cities. Differences Cities Informal settlements: High to low levels of un- to under-serviced households Lusaka -70%, Windhoek—45%, Durban— 28%, Harare -9 to 13% Water scarcity: Highest in Windhoek, then Harare and Lusaka Harare, Lusaka and Windhoek Water supply: Controlled by public entities Harare and Durban Managed by a private company Lusaka and Windhoek Energy supply: Mostly coal driven Durban Mostly biomass (wood) then hydro-powered Harare, Lusaka, Windhoek Harare City-specific Windhoek Controlled by public entities Durban, Harare, Lusaka City climate integration and planning: Climate change integrated in city climate change strategy Durban Advanced stages to integrate climate policy and action from national level to local government level planning Windhoek Still to develop Climate Change Strategy and Action plan Harare and Lusaka https://doi.org/10.1371/journal.pone.0227915.t004 City learning in southern Africa

PLOS ONE | https://doi.org/10.1371/journal.pone.0227915 January 24, 2020 12 / 25