As per the artist himself
The original photo was posted to flickr on March 20th, 2010. It is not real, it’s a composite of two photographs: One is mine “Darren Pearson” (a photo of a tree taken at the Presidio in San Diego, CA) and the other is from the NOAA webpage:
My image is a long exposure, 619 seconds, taken at night. During this time, I used ‘el wire’ to create the blue smoke-looking effect, and a color-gelled spotlight to give the tree a pink glow.
The lightning bolt was an idea that my roommate Joey (also a photographer/filmmaker) had while I was processing the photo. He mentioned, “You know what would be incredible? A lightning bolt striking the tree!” I was amused by this idea, and added in the lightning, which I thought looked awesome!
I never intended it to be taken for a real photo of lightning striking a tree. It was meant to be an artistic expression, but turned into an internet misinformation fiasco. (An interview with the artist – Darren Pearson)