It began pretty accurately in 1987 in a dramatic very non-linear fashion. Later on, in 1992 its growth as slowed considerably.
At least on paper... Google offers a fancy tool to sample the frequency of any words in its vast and growing pool of scanned books. A search of 'global warming yields the following figure
The hockey stick, on the other hand, continued its recovery from the Little Ice Age without any remarkable jumps or acceleration after 1998. Is its recent declined the result of natural variability or the response to evil forgings ?