As the world marked World Cities Day, the conversation often turned to sleek green buildings, electric transport, and carbon-neutral skylines. Yet for the over one billion people living in slums and informal settlements, climate change is not an abstract future threat—it is a daily reality. Flooded latrines, contaminated water, and destroyed homes are their normal.
Net-zero policies frequently overlook these communities. Low-income urban residents are not the problem and they have comparatively low carbon footprints. They live in high-density, shared housing, rely on public transport, and consume far less energy than wealthier citizens. Some behaviours, like cooking with charcoal or relying on pit latrines, do contribute to emissions, but these are small compared with the carbon-intensive lifestyles of richer urban populations.
The injustice lies in vulnerability. Informal settlements are often located in the most climate-exposed parts of cities, along rivers, on steep hillsides, or in flood-prone zones. Access to services like water and electricity is fragile. Livelihoods are insecure, and savings are minimal. When floods strike or droughts worsen, the poorest communities bear the brunt.
Yet these same communities could benefit disproportionately from climate action if it were planned inclusively. Take sanitation. The majority of urban residents in the Global South rely on pit latrines. When these are not emptied or treated, they release methane, a greenhouse gas far more potent than carbon dioxide. Proper faecal sludge management not only improves health but also replaces methane emissions with carbon dioxide, reducing global warming. Estimates suggest sanitation accounts for around 5% of human-made methane emissions, a significant opportunity for climate mitigation.
WSUP’s work demonstrates that climate-resilient sanitation is achievable. From flood-proof drains to waste-to-value solutions, inclusive urban systems can be built but only if sanitation is recognised as essential public infrastructure rather than an afterthought.
Net-zero planning that focuses only on energy or transport risks creating resilience for the connected, while leaving the most vulnerable behind. It is a profound injustice that less than one percent of climate finance addresses the sanitation crisis in slums. Floods spread sewage, droughts paralyse water systems, and the poorest suffer most. Climate funds must strengthen utilities and embed sanitation at the heart of national strategies.
As World Cities Day reminds us, cities are only as resilient as their most vulnerable residents. By prioritising inclusive, climate-resilient sanitation, we can tackle health, inequality, and climate crises simultaneously. Net-zero plans that ignore informal settlements are not just incomplete, they are unjust.
For the over one billion people in slums, climate change is not a future threat, it is a daily reality of flooded latrines and contaminated water. Net-zero plans that focus only on energy and transport risk building climate resilience for the connected, while leaving the most vulnerable behind. Sanitation must sit at the heart of climate adaptation and national net-zero planning.