Of the eccentricity Milankovitch cycle we have 139 years of temperature data.

That means we are missing 99.86% of the temperature data for that 100,000 year cycle.

Of the axial Milankovitch cycle we have 139 years of temperature data.

That means we are missing 99.66% of the temperature data for that 41,000 year cycle.

Of the precession Milankovitch cycle we have 139 years of temperature data.

That means we are missing 99.4% of the temperature data for that 23,000 year cycle.

If ice core samples could accurately measure historical temperature data then wouldn't it be logical that NASA's little chart would have temperature data going back further than 1880 as your link above shows? The reason they stop at 1800 is because that's the furthest we can go back with any accuracy, and that's why the Farmer's Almanac was so popular, it's when we in more modern times started to get the hang of weather patterns and growing seasons. Anything outside of measuring the temperature in real time is theoretical. Crippling industry in favor of a carbon tax will not significantly change the climate, but it will cause people to starve to death and increase the dire economic circumstances that mankind is currently facing.

I would encourage you to check this out starting
at page 10 of the .pdf As they say, shift happens,
and their ain't much that we can do about it. We
are all subjected to mother nature and her wrath.