Cities at a Crossroads: Urbanisation, Climate Change, and Global Inequities

A major aspect of urbanisation is rural populations moving to cities. This has been driven by factors such as the standardisation of education systems, the expansion of international trade through market globalisation, and the decline of traditional rural livelihoods due to climate change. Since 1900, urbanisation has surged from 16% to over half the global population in 2023. Concentrated industry, transport, and energy use in urban areas now generate over 70% of global emissions, making them key targets for decarbonisation and emissions reduction.

Urbanisation also exacerbates climate change. Paved surfaces in cities limit water absorption, overwhelming drainage systems during increasingly frequent intense rainfall events. Urban infrastructure, including buildings and roads, intensifies city temperatures relative to nearby rural areas through the “urban heat island“ effect, caused by heat-absorbing materials, reduced vegetation, and human activities. This warming drives higher energy consumption and worsens health issues, such as heat strokes and respiratory problems. This complex relationship between urbanisation and climate change presents significant challenges for sustainability and human well-being. 

Impacts in the Global South – Nairobi, Kenya 

There is a stark imbalance between responsibility for the climate crisis and its impact: the Global North* accounts for 92% of historical emissions globally, while the Global South* remains the most vulnerable, due to both geographical factors and enduring power imbalances rooted in colonialism and global dominance —all without having reaped the benefits of fossil fuel exploitation. 

Climate change often forces people into cities by disrupting ecosystems and making traditional livelihoods unsustainable. Others migrate to urban areas for better jobs and opportunities. However, long-standing social inequalities and modern exploitation often confine these populations to substandard living conditions in informal settlements. 

In Nairobi, approximately 75% of urban residents live in informal settlements, which occupy only 5% of the city’s land, generally in the most precarious places. These areas, characterised by poor infrastructure, inadequate sanitation, and limited access to clean water, provide essential services and affordability for those neglected by the government. 

Flooding is a significant issue in Nairobi’s informal settlements, compounded by rapid, poorly planned urbanisation. Earlier this year, floods in Kenya claimed at least  270 lives and affected 380,000 people, many from Nairobi’s informal settlements. The already inadequate infrastructure has left residents exposed to waterborne diseases as overwhelmed sanitation systems are inundated by floodwaters.  

It is crucial to strengthen the resilience of both these communities and the infrastructure they depend on, as such events become increasingly intense and frequent. 

The UK and Future Perspectives 

The cities of the UK are also experiencing climate change effects through flooding and droughts. Again, it is the poorest and most marginalised who are most vulnerable, receiving the least attention in terms of funding and maintenance. Urbanisation and gentrification worsen this issue. pushing low-income households further into the periphery, causing further inequity in access to essential social goods.

Approximately 25% of the UK’s greenhouse gas emissions come from the construction industry, driven by energy-intensive materials and methods used in urban development. To reduce these emissions, it is essential to cut both embodied and life-cycle emissions by carefully selecting construction materials and rationalising their arrangement within buildings. Simple designs are inherently less material-intensive and more efficient. This approach is vital for new structures, but equally important is retrofitting existing buildings to maximise energy efficiency. Urban spaces should be designed with residents’ needs at the forefront, rather than the interests of developers. This means developing good public transport networks, maintaining expansive green spaces, providing genuinely affordable housing, and ensuring well-designed, well-maintained, and well operated utilities (we could also nationalise them while we are at it?). 

Urbanisation is a process deeply intertwined with climate change, a relationship rooted in capitalism and colonialism. Improving cities in the Global North* will contribute to reducing future emissions, but this must go hand in hand with emerging initiatives such as the Global Goal on Adaptation and the Loss and Damage Fund. These could be vital tools in making necessary reparations and building resilience to climate events. However, there is still much to understand about how they will operate in practice. 

Human-induced climate change will demand radical behaviour shifts in the coming years. It would be a welcome change to focus on pre-empting challenges rather than simply reacting. This might be uncomfortable, this might be tough, but this is the most difficult challenge humanity has ever faced, so maybe it’s time for compromise?

*Please note: In this blog I use the terms Global North and Global South to discuss global disparities, particularly around climate impacts and urbanisation. While these terms are imperfect and can oversimplify complex social, economic, and political realities, they serve as shorthand to distinguish between historically industrialised nations (often in the Northern Hemisphere) and countries that have faced colonial exploitation and continue to bear the burdens of economic and environmental injustice. In the absence of more accurate language, I will use Global North and Global South here to facilitate this discussion while acknowledging the limitations of these terms.

Written by James Wallace, PhD researcher from the School of Civil Engineering focusing on the intersection of flood risk analysis and climate-resilient sanitation systems. Through a Nairobi case study, his research examines how urbanisation and climate change impact equitable access to sanitation services in informal settlements.

Featured image: Night Lights – London by Untalented Guy

Images in blog:
1. River running through Kibera, Nairobi’s largest informal settlement (Credit: Buro Happold)
2. Derelict community pub overlooked ominously by a new-build apartment complex. Ancoats, Manchester (Credit: James Wallace)