My hypothesis is that the natural 1998 temperature spike was crucial in selling both scientists and the public on the validity of Mann's bogus hockey stick. If the exact same paper had been published after, say, an 18+ year hiatus, not nearly as many people would have been fooled.
This article looks back at the late 1990s
Many scientists who had until then remained sceptical of climate change were convinced and the headlines and broadcasts meant that large swathes of the public were simultaneously concerned about the activities of the oil companies, the profligate use of coal and oil in developed countries, and the amount of carbon dioxide pouring into the atmosphere.IPCC TAR and the hockey stick | Climate Etc.
JC comments: Christy’s assessment, when combined with the UEA emails, provides substantial insight into how this hockey stick travesty occurred. My main unanswered question is: How did Michael Mann become a Lead Author on the TAR? He received his Ph.D. in 1998, and presumably he was nominated or selected before the ink was dry on his Ph.D. It is my suspicion that the U.S. did not nominate Mann (why would they nominate someone for this chapter without a Ph.D.?) Here is the only thing I can find on the U.S. nomination process [link]. Instead, I suspect that the IPCC Bureau selected Mann; it seems that someone (John Houghton?) was enamored of the hockey stick and wanted to see it featured prominently in the TAR. The actual selection of Lead Authors by the IPCC Bureau is indeed a mysterious process.Note in Mann's book "The Hockey Stick and the Climate Wars", page 26, Mann suggests that skepticism was just fine in the early 1990s--you might say his advisor Barry Saltzman was skeptical, and Mann's "was closer to Barry's position than Hansen's or Schneider's.
Note the 1998 temperature spike.