Did humans influence climate change 13,000 years ago?

 #33  August 27:  I’m still thinking about an article in Monday’s paper via the LA Times.  It talked about the relatively quick (200 years) climate change that occurred during the age of the La Brea tar pits 13,000 years ago.  We visited them several times when we were in Los Angeles.  According to this article, humans entered the picture near the end of the animals’ demise.  The landscape around LA and southern California changed from prehistoric woodland to a chaparral in just 200 years.  Emily Lindsey, a curator at the La Brea Tar Pits studied the bones of the animals and linked their demise to a study of the layers of sand and debris, especially charcoal they were able to date at the bottom of nearby Lake Elsinore.  While nature creates wildfires, the incidence of wildfires increased significantly with the arrival of humans.  They brought fire with them, but had little means to control it.  Coinciding with a natural drought phase, this resulted in the demise of the forest and the animals in the tar pits.  After this 200 year phase, the trees had changed to drought resistant pines and a flora and fauna associated with the chaparral.  It took 200 years for a relatively small amount of humans to cause this big change. Now with carbon emissions and many more humans, we see an even more rapid climate change, but the parallels are there and scary! 8/24