Nobel Peace Laureates joined millions of protesters around the world for the global movement over climate change on Friday (September 20), calling for urgent steps to be taken to save the environment.
Colombia's former president Juan Manuel Santos and Guatemala's Rigoberta Menchu were amongst the laureates to mark the occasion.
Global warming caused by heat-trapping greenhouse gases from burning fossil fuels has already led to droughts and heat waves, melting glaciers, rising sea levels and floods, according to scientists.
Dozens of Nobel Peace Prize laureates are in the Mexican city for the 17th World Summit, in an event that seeks to advance issues of global peace.
Menchu won the Nobel Peace Prize in 1992 for her work in promoting indigenous rights in Guatemala. Speaking in Merida, Menchu touched on migration and the benefits it brings to the world.
The four-day event wraps up on Saturday (September 21).