UC Santa Barbara

Africa’s urban population will increase from 600 million people today to nearly 1.5 billion in 2050. The vast majority of new urban residents will be poor and will face a host of challenges that are amplified by climate change. Chief among them is how to reduce urban poverty and ensure food security. Yet, due to a persistent lack of data, the feedbacks among food security, urbanization, and climate change in Africa have not been explored. This knowledge gap directly impedes progress to achieve the United Nations Sustainable Development Goals 1, 2, and 11—ending poverty, zero hunger, and ensuring sustainable and equitable cities.

This dissertation takes a step towards linking these themes. First, using original data collected in Accra, Ghana, I examine urban food security measurement. I find that while poverty is generally correlated with households’ experiences with food insecurity, traditional dietary-recall metrics may not be appropriate measures of household food security in African cities. Next, I integrate OpenStreetMap data and gridded population datasets to map the populations of 4,500 urban settlements in Africa. This approach fills a crucial void in our capacity to measure urban population dynamics across the continent. Finally, I document how urban exposure to extreme heat changed from 1983 - 2016 not just in Africa, but across 13,000 towns and cities globally. This is the first fine-resolution, global synthesis of urban population exposure to extreme heat. I argue that mitigating exposure to extreme heat is key to reducing urban poverty and thus ensuring food security. But mitigation efforts must be tailored to local contexts. In sum, the results of this dissertation call into question the sustainable and equitable development of Africa’s ever-expanding urban areas.