climate change is a handle used to describe a range of global climate that is diverging wildly from the average....(don't ask me what the average is.....
)....probably "since records began"....
think about it,
"since records began" no one has used the Northwest Passage, Antarctica is loosing ice cover (arguably these last two will be limited to our 'modern' knowledge of (say) 200 years), as is Greenland and some of the mountain ranges. permafrost is melting during summer months, as well as ice around the North Pole.