While in Paris for the climate change summit, President Obama was optimistic. "The main message I got is that I actually think we are going to solve this thing," he said Tuesday. His optimism, though, was not shared by a network of artists, which installed more than 600 works of art on the streets of Paris critiquing the corporate sponsors of the talks.

“We knew about the impact of fossil fuels put publicly denied it” read one of the posters, installed at a bus stop. Another mocking an advertisement for Air France read, “Tackling climate change? Of course not. We’re an airline.”

According to the Associated Press, the eco-activists placed the works of art in advertising spaces owned by JC Decaux, which, according to the network's news release, is “one of the world’s largest outdoor advertising firms and an official sponsor to the COP21 climate talks.”

“Advertising is the engine of consumerism, telling us to buy more and more things regardless of the environment impact,” Peter Marcuse, a member of the Brandalism network, told the AP. Marcuse said the installation is intended to “make the link between advertising and climate change.”

The installation was created by more than 80 artists from 19 countries. Here’s a look: