The members of Greenpeace deployed a large protest banner on a building in Madrid ahead of Spain's general election at the end of April.
The yellow flag represents an invoice that lists the impact political decisions are having on climate and human rights, according to the NGO.
Four climbers reached the top of the 60-metre high Torres de Colón to display the 300-square-metre banner.
Spain holds general elections on April 28 and Greenpeace calls on the country's main political parties to act to stop climate change.
