Geology Lunch – Skipped Beats of Earths Climate – 10/9/2018


Come to GeoLunch, Tuesday 12 – 1  October 9, 2018

Carnegie 219

Pizza and cider to be served while we speak about Climate.

Skipped Beats of Earths Climate – The past and future of glacial cycles..
Over the last 2 million years, Earth’s climate has periodically cycled between warm and cold states –
the so-called glacial and interglacial climates. We are currently in an interglacial phase that began
about 11,000 years ago. During the glacial states, ice sheets covered large areas of the northern
hemisphere land mass and consequently sea levels were lower than today. The shift between these
climate states is very likely driven by periodic oscillations in Earth’s axial tilt which cycles
approximately 41,000 years. For the first one million years of the glacial cycles, they recurred with
the same period. However, the latter half saw the glacial cycles occurring in intervals of 80k and
120k years, i.e., 2x or 3x the period of axial variations. In this talk, I’ll present a working hypothesis
to explain the skipped beats of glacial cycles and a prognosis for the future climate state of Earth.