A new WaterAid research study published today reveals how the world’s 100 most populated cities are becoming increasingly exposed to floods and droughts – as governments around the world slash the aid budgets providing global health and climate security.

Developed with academics from University of Bristol and Cardiff University, the new study compares each city’s social and water infrastructure vulnerabilities alongside 40+ years-worth of new data on climate hazards – concluding which cities and communities worldwide are the most vulnerable to extreme climate changes and the least equipped to handle them.

The report ‘Water and Climate: Rising Risks for Urban Populations’ exposes how cities across Africa and Asia are emerging as the most at-risk to extreme climate shifts worldwide, which is having a devastating impact on access to clean water for urban communities on the frontline of climate change.

Almost 1 in 5 (17%) of cities studied emerge as experiencing ‘climate whiplash’ - intensifying droughts and floods - where 20% of cities have seen a major flip from one extreme to the other. Cities in Southern Asian are becoming overwhelmingly flood-prone and European cities are exhibiting significant drying trends, all of which can impact people’s clean water access and water security.

All European cities analysed exhibit drying trends over the last 42 years, including Madrid (Spain), Paris (France) and London (UK) – which could lead to the region facing more frequent and long-lasting droughts. Madrid and Barcelona both show ‘climate hazard flips’, with Madrid ranking second on the list of cities experiencing a flip to extreme dry conditions.

From recent drought in cities like Madrid (Spain) and Cape Town (South Africa), to large-scale flooding across cities in Bangladesh and Pakistan, 90% of all climate disasters are driven by too much or too little water.

WaterAid, the world’s leading water, sanitation and hygiene charity, warns that weather-related disasters such as flooding and drought have increased by 400% in the last 50 years, putting major pressure on vital water access and sanitation systems and making it harder for communities and economies to prepare for, recover from, and adapt to climate change.

The vulnerabilities the report examines range from poverty to poor water and waste systems – exposing ever-expanding urban populations to risk from intensifying floods or droughts, leading to displacement, instability and loss of life. Severe urban flooding can damage sanitation facilities, spreading diseases such as cholera and typhoid, whilst water shortages during droughts are leaving millions of families without the water they need to survive.

Key findings include:

• 20% of the cities studied are experiencing dramatic shifts to extreme wet or extreme dry conditions, referred to as ‘climate hazard flips.’ Approximately 13% are flipping toward a more extreme wet climate, while about 7% are flipping toward a more extreme dry climate. This amounts to over a quarter of a billion people across the world experiencing a major flip in their climate, including in cities such as Kano (Nigeria), Bogota (Colombia) and Cairo (Egypt), placing major pressure on access to safe and clean water.
• 17 cities across multiple continents – 15% of the cities studied - are experiencing an intensification of both extreme floods and droughts, known as ‘climate whiplash’, including Addis Ababa (Ethiopia), Hangzhou (China), and Jakarta (Indonesia)
• South and Southeast Asia emerges as a regional hotspot, with Colombo (Sri Lanka), Faisalabad (Pakistan), and Lahore (Pakistan) seeing the most dramatic flip from historically dry conditions to becoming severely flood prone
• All European cities studied including Madrid and Paris are exhibiting significant drying trends, with Madrid ranked 2nd among the 49 drying cities, and London ranked 44th

By looking at social and infrastructural vulnerability alongside the climate data, the report, with hotspots of heightened risk in two key regions: south and southeast Asia, and north and east Africa. The cities identified as the most vulnerable include Khartoum (Sudan), Faisalabad and Lahore (Pakistan), Baghdad (Iraq), Surabaya (Indonesia), Nairobi (Kenya), and Addis Ababa (Ethiopia)

The report also places European cities like Barcelona, Berlin and Paris at a higher risk than those in North America and Australia, due to the continent’s aging water and waste infrastructure, potentially leaving urban populations more vulnerable to a changing climate

Report highlights devastating shifts in extreme climate patterns across all continents

Tim Wainwright, WaterAid UK’s Chief Executive, said:

“This research comes at a pivotal time, as we’re seeing a sweep of global aid cuts, which could leave basic human rights hanging in the balance.

“This report highlights the devastating shifts in extreme climate patterns across all continents, with the impact felt most clearly on low-income countries, where the absence of water becomes not just a challenge, but a matter of life and death.

“Floods and droughts are stripping away people’s foundation of survival – water. But with a reliable supply of clean water, communities can recover from disasters, stay healthy, and be ready for whatever the future holds. It all starts with clean water.”

WaterAid is calling for:

• The UK Government to show leadership by ensuring the UK upholds its foreign aid commitments and protecting its promise to fund climate adaptation efforts, to tackle the water crisis.
• UK Government to protect its current International Climate Finance commitments and invest a third of its adaptation budget in water action, to enable countries to integrate climate resilient water measures into their plans to support vulnerable communities on the front line of the climate crisis.
• The UK Government to leverage collective action and work with development partners, multilateral banks and the private sector to to unlock investment to manage water risks;
• The Foreign Office to launch an international water security strategy and imbed action on the water crisis across all areas of UK foreign policy.

Professor Katerina Michaelides, Lead Scientist from University of Bristol, commented:

“The findings from our study illustrate just how differently and dramatically climate change is expressing around the globe – there is no one-size-fits-all.

"Places that were historically wet are becoming dry and vice versa. Other places are now increasingly battered by both extreme floods and droughts. A deeper understanding of localized climate hazards can support more intelligent and bespoke planning in major cities.”

Click here to dowload the report in full