As far as global warming, who was burning fossil fuels 100,000 years ago to cause that warming?

How about 18,000 years ago at the end of the Pleistocene? Lots of fossil fuel burning going on then?

Climate is a described by coupled sets of non-linear relationships whose actual variables haven't even been convincingly identified.

Those pointing to computer models are either frauds or incompetent; as the models are worthless. Every single line of that code needs to be held up to the light of day; the fudge factors, approximated physics, poor math, and then the whole sections where they have no idea but just wing it.

Global warming is just a tool to empower bureaucrats and unaccountable international organizations who want to control you. With communism and socialism disreputable, it's the new vehicle.

Known causes of climate change:

(1) Astronomical Causes

11 year and 206 year cycles: Cycles of solar variability ( sunspot activity )
21,000 year cycle: Earth's combined tilt and elliptical orbit around the Sun ( precession of the equinoxes )
41,000 year cycle: Cycle of the +/- 1.5° wobble in Earth's orbit ( tilt )
100,000 year cycle: Variations in the shape of Earth's elliptical orbit ( cycle of eccentricity )


(2) Atmospheric Causes

Heat retention: Due to atmospheric gases, mostly gaseous water vapor (not droplets), also carbon dioxide, methane, and a few other miscellaneous gases-- the "greenhouse effect"
Solar reflectivity: Due to white clouds, volcanic dust, polar ice caps


(3) Tectonic Causes

Landmass distribution: Shifting continents (continental drift) causing changes in circulatory patterns of ocean currents. It seems that whenever there is a large land mass at one of the Earth's poles, either the north pole or south pole, there are ice ages.

Undersea ridge activity: "Sea floor spreading" (associated with continental drift) causing variations in ocean displacement.