Climate Change Seminar - The Climate record and temperature gradients in the earth.

The types of record of climate change are myriad. One type of evidence that is often neglected, but has some advantages, is analysis of the shallow thermal gradient. Imagine a tracker finding a campfire pit, touching the ground, and saying, "they left only two-three hours ago." In courses on remote sensing infrared photos are sometimes shown of a thermal shadow left on the tarmack after the planes have left. The ground remembers its past thermal history.

A bit of heat-flow science:

Thermal diffusivity:

Discussion questions:

Summary: This crude but robust technique provides results consistent with global warming in the last century. However, it doesn't address the causes.

Convergent validity and explanatory power in the context of multiple records.


Discussion question for next time: Concentrate in on the graphs showing various signals (dust/ash content, methane, carbon dioxide, various isotope values) in the vertical ice core successions. Which ones correlate well with each other? Which ones ones don't? What are some of the system links behind these correlations or lack thereof.

Readings: