You have hit on a very interesting piece of evidence by considering the frequency of google searches. But I fail to see why you consider this points to a switch in 2014 in the media? Firstly, the myth is far older than 2014. Note that this SkS OP dates from January 2011. And secondly, if you extend your google search data back to the start of the data (2004), the evidence shows the term "Global Warming" was by far the more popular term used in searches but began to slowly decline from that dominant position from 2007, while the term "Climate Change" has been the subject of increasing use in google searches from the start of the data in 2004. Note the two terms when used in the search "What is ..." still gives "Global Warming" the edge in popularity.