A new version of the climate challenges for citizens has been introduced in Nantes Métropole, with the goal of increasing participation from 400 to 1 000 households annually. Since 2011, this initiative aims to support residents of Nantes Métropole in changing their lifestyles and reducing their environmental footprint. That's why the format is evolving this year, with new themes addressed such as food, mobility, waste, energy or water. Residents will be able to participate in individual mini-challenges through a dedicated application developed for this purpose, or in collective challenges (groups of friends, neighbors or associations) on the theme of their choice. Each challenge will last three or six months and will provide access to support from facilitators who will offer engaging workshops and conferences.