You said it.
Your question is based on a false premise. "Global warming" was not changed to "Climate change"; the two terms refer to different phonomena and both have been in use for a long time.
Firstly, the term "climate change" (and "climatic change") was in use in the scientific literature before the term "global warming".
Secondly, the terms have different meanings. "Global warming" refers to the long-term increase in global temperature, while "climate change" refers to changes including, but not limited to, temperature.
An advisor to the Bush administration did circulate a memo recommending that Republicans refer to "climate change" instead of "global warming", because the former sound less "catastrophic".
In his memorandum, Mr. Luntz urges that the term "climate change" be used instead of "global warming," because "while global warming has catastrophic communications attached to it, climate change sounds a more controllable and less emotional challenge."
However, by this time, both "climate change" and "global warming" were already in common use in the scientific literature.
For example, CO2 emissions increased by more than 20% yet the the warming increased by less 0.3% in the same time frame, or even far longer?
If you can provide a source for this claim, I'll look at it and give you a response. I won't respond until I can verify that your numbers come from real measurements. (For all I know, you could be quoting some made-up numbers from a blog.)
These 500 gentlemen, most are experts, not shrill alarmists who have been crying like Chicken Little, " The sky is falling, the sky is falling!
I didn't watch the video, but the video description included the list of signatories:
https://clintel.nl/wp-content/uploads/2019/09/ED-brochureversieNWA4.pdf
I can identify one climate scientist, Richard Lindzen, and there's a couple more I'm unsure about, but the overwhelming majority of the signatories on that list are definitely not experts on climate.
As I said:
I shouldn't have to explain this, but none of the following people qualify as experts on climate science:
- Politicians
- Media personalities
- Activists
- Scientists whose field is not climate science
- Bloggers
Only the following people qualify as experts: