All of Human civilization fits neatly into the current interglacial period. The development of agriculture, settlements and societies were all enabled by a beneficial climate for the last 10,000 years.
Interglacials usually average ~10,000 years so is our luck about to run out? It turns out that the answer is no, because we are very fortunate that human society has developed during an interglacial when the earth’s orbit has very low eccentricity.
Eccentricity is important because it regulates the strength of polar maximum summer insolation caused by precession of the equinoxes every 21,000 years. Precession determines the distance from the sun during a Polar summer. If summer coincides with the earth’s perihelion then summer insolation can be up to 20% higher than average. However if the earth’s orbit is nearly circular, as it is today, then precession has little effect at all. That is why we have about 15000 years left before cooling begins.



















