Methane levels, according to Ice Core samples, go up and down, correlating to
temperature variations, for the last, oh, four hundred thousand years or so.
The chart provided seems very cyclical to me. I am wondering why, about a
110,000 years ago, there were high methane levels, and high temperatures,
when my grandfather didn't yet have his SUV? And why, about 110,000 years
before that, before his grandfather had a model T, we see another spike in
methane and temperature level?