SAN FRANCISCO, Nov 13 — Greta Thunberg will gaze down at people from a building in downtown San Francisco from Tuesday night when an artist formally unveils a giant mural of the teenage activist, hoping it will remind residents of the dangers posed by climate change.

The 60-foot tall, 30-foot wide (18-by-9 metre) mural was created by Argentine street artist Andres Petreselli, who also painted a since demolished mural of the late actor Robin Williams in San Francisco.

Petreselli, who signs his art as Cobre, says he usually does not address politics, religion or sports in his art.

"But, this one is ... I feel connected with the politics behind (it) because I think it is real and if I have to compare it with the rest of my murals, this is the most political one that I ever made,” the 32-year-old said as he sat on a roof with the mural behind him.

Paul Scott, the executive director of OneAtmosphere.org, the San Francisco nonprofit that funded the work, said he hoped passers-by would be "touched” by the image of Thunberg, who has mobilised a global youth movement against climate change.

"We are really just hoping that it stops and makes them think, that this will amplify Greta’s message, that people will start to understand the clear call for action that she is sending out,” Scott said. — Reuters