The C40 World Mayors Summit held in Rio de Janeiro brought together mayors from around the world to discuss urgent climate action in the face of rising global temperatures and skepticism from political leaders. With cities responsible for 75% of global carbon emissions, the summit aimed to empower local leaders to implement innovative solutions. Mayors like Sadiq Khan of London and Eduardo Paes of Rio emphasized the importance of local governance in combating climate change. Various mayors shared their initiatives, such as Milan's low-emission zones and Phoenix's efforts to manage extreme heat. The summit highlighted the need for collaboration and action at the municipal level, especially as global climate talks approach, underscoring the critical role cities play in addressing the climate crisis.