C40 Co-Chair Mayor Aki-Sawyerr and climate expert Aromar Revi react to extreme weather events in C40 cities

A statement by Co-Chair Mayor Yvonne Aki-Sawyerr OBE and Indian Institute for Human Settlements Director, IPCC AR6 Coordinating Lead Aromar Revi

The consequences of extreme weather events are devastating communities worldwide. 

Cities across the C40 network are experiencing the dire consequences of storms, drought, heavy rain and extreme heat waves, exacerbated by the climate crisis and its impacts. 

The science is clear:

• Human activity is changing our climate (IPCC)
• Climate change makes heat waves, storms and droughts worse (AMS);
• The climate crisis is increasing the frequency and intensity of heavy rainfall and other extreme weather events (IPCC)

Climate change is real; it is caused by fossil fuel emissions, and it looks like this: 

In Africa, widespread floods and landslides have had fatal impacts. 

Dar Es Salaam, Tanzania is directly experiencing the impacts of El Niño. Heavy rains, flooding and landslides destroyed critical infrastructure and homes. More than 155 people were reported dead. Habitats and lives are gone. There is a need for accelerated focus on climate resilience with more emphasis on coastal areas.

There have also been floods in Nairobi, Kenya, with mass evacuations to stop more lives from being lost after over 180 people were reported dead. 

Extreme flooding, once deemed rare in parts of regions such as Central East Asia, is now becoming more frequent. 

In Guangzhou, China's main transport and trading hub, a tornado wreaked destruction and claimed the lives of five residents. 

Record rainfall in Brazil is wreaking destruction and devastation.

According to The New York Times, in the last four days of April, the state of Rio Grande do Sul in Brazil received about 70% of the precipitation it typically records for the entire month. Such heavy rainfall burst rivers, flooding towns, claiming lives and destroying infrastructure. 538,000 people are now without homes due to the flooding, and 85% of Porto Alegre's population currently have no access to water. The central state airport in the capital is flooded, and most roads connecting the capital to smaller cities are also flooded, making emergency relief measures much more difficult.

Across Asia, cities are battling extreme weather events, from heatwaves to flooding. 

Across South Asia, cities are battling extreme weather events, from heatwaves to flooding. In India, temperatures have exceeded 40°C. In Bangladesh, temperatures have already exceeded this prediction, with schools being closed in recent weeks because of the severity of the heatwave and the risk to public health. In the Middle East, the UAE experienced what some outlets describe as ‘apocalyptic’ floods.

Heat has been endangering lives across Southeast Asia, with reports that temperatures hit over 40°C in Thailand, Laos, Philippines, Myanmar and Indonesia.

In Canada, wildfires are already burning and causing the evacuation of entire communities.  

Some wildfires did not stop burning in the Canadian winter, becoming known as “zombie wildfires” following the unprecedented wildfire season in 2023. 

C40 Cities are already taking action to address extreme weather events, showing that political leadership can save lives and make communities more resilient to flooding and drought. Still, we need to act even faster to prevent further disasters. 

C40 Co-Chair and Mayor of Freetown Yvonne Aki-Sawyerr OBE said: “The challenge is clear: Without drastically reducing fossil fuel use in order to at least halve our emissions by 2030 we will likely be condemning ourselves to a future filled with never-ending news of extreme weather events. Achieving this goal will take all hands on deck. We stand ready to address this emergency and call on all governments, companies, and residents to act with us.”

C40 Vice Chair and Governor of Nairobi Sakaja Johnson said: "Nairobi continues to be on high alert and we have mapped out the most affected households to assist our communities as we continue to mobilise relief items to support those affected. We have lost about 20 people with about 60 000 persons including women and youth being affected. We are witnessing how vulnerable our city is to climate change. We are reaching a point where we have no other choice than taking actions to beat climate change and build resilient cities across Africa.''

Indian Institute for Human Settlements Director and IPCC AR6 Coordinating Lead, Author and Climate Expert Aromar Revi said: “Global warming is set to exceed the 1.5oC guardrail in just over a decade. Observed warming is well over 2oC in cities in many regions. While we wait for countries and the fossil fuel industry to dramatically reduce emissions, we need to deploy a range of known measures to reduce vulnerability and adapt to extreme weather and heatwaves in cities across the world. The time for climate resilient development is here and now.”