When you interpolate, you average which can be called smearing if you are looking for detail. I had a client show up with a brand new Kridged version of NOAA ocean bottom charts and wanted me to show him how to bottom fish. My first advice was to throw that smoothed crap away and get a "real" chart, that shows all the warts, wrinkles and bottom "features." The world and the ocean bottom isn't as smooth as a baby's butt. Those "warts" are beauty marks to a bottom fisherman.
Climate products are the same deal Lucile. California for example has paleo, observational and anecdotal evidence of century long variation in precipitation extremes. The winter of 1861 and 1862 is known as the Great California Flood. For a few months there was Lake San Joaquin and quite a few home owners abandoned their first floor and built on top. Cities tried to increase their elevation by 15 feet or so, just in case. Then there are decade long droughts that make the flood wary folks look stupid. Nature is good at that, making people look stupid, often in very cruel ways.
Since "Global" Climate Change is the catastrophic cause of the day, smart people that nature tends to have an affinity for making look stupid, are putting all their eggs in the global basket while neglecting the mundane local and regional baskettes where people tend to live. Using long range interpolation tends to make local and regional pictures of past climate look rosier that reality.
Think about this, "The Little Ice Age was a regional event." Wonderful, "Globally" it didn't exist so all you morons with regional concerns are wasting your time worrying about that kind of stuff happening again, think Global!! Ever wonder why there is a populist movement?
Now that there is a new administration in town, "Globalists" are going to have a lot of explaining to do. I expect to see climate scientist types out there counter protesting natural gas pipelines that reduce emissions and are a bridge to those elusive energies of the future. Perhaps a few fighting for sensational press releases of "it isn't as bad as we thought" research to calm the irritable masses.
Will we actually see any rational leaders emerge? Stay tuned.