The French capital is transforming its iconic promenade into a green oasis.
The One Planet Summit hopes to reignite discussions about protecting nature and people.
It came just three months before the deadly November 13 attacks in Paris.
The event was organised by the German Embassy in Paris to celebrate Franco-German relations and show solidarity amid the ongoing coronavirus pandemic.
"This fine is obviously absurd. What's more, it is unfair, irresponsible and dangerous," Paris Mayor Anne Hidalgo has said.
France's top administrative body ruled in favour of the Catholic church on Sunday saying the 30 person limit in places of worship across the country was too restrictive.
The countdown to Christmas is underway in European capitals Brussels and Paris.
The lights are set to stay until January 6, but far fewer people will be there to enjoy them this year.
The lights are on, but no-one is home.
Sign language interpreters performed alongside artists at a hip hop concert -- without a live audience -- that took place in Paris on Saturday.