25 years ago climatologists were warning us of the imminent new Ice Age. The reality of global warming at all, per se, is still very much unproven,lurking as it does in the range of statistical error, much less anthropogenic global warming. Your sequence of lines in the sand may reflect the media presentation of skeptical observers, or the random opinions of psoters here, but it does not do justice to real climate scientists who have serioous and abiding doubts about it all. The jury is very much out--and the most powerful proof is the blind raging assertions of "There is NO DEBATE!" howled by the GW enthusiasts. If they had the data they would stand in line to debate. But sensible people like Lonborg are still shunned.
No. It's been "warming" since the early 50s according my experience and "warming" since the 1870s according to my reading. Of course, the press may have written otherwise at times.