Tom Nordblum
Tim Hutchings introduced today's guest speaker, noting that Tom had supervised his PHD work at the university.
Tom spoke on the Causes of Ice Ages on Earth, and our scope for effectively adapting to these changes. He identified three factors that influenced changes to climate and temperature on the planet:
* Precession - Earth wobbling on its axis.
* Obliquity - Variation in tilt of Earth's axis.
* Orbital eccentricity - The orbit is not a circle.
These factors are not short term - the cycles of change cover tens to hundreds of thousands of years.
We saw many graphs showing variations to physical parameters on earth - including.
* The LR04 Benthic Stack of deep-seabed sediment cores for 5.3 million year record of sea levels.
* Inter-hemispheric isolation phase systems at Orbital Scale.
* 65 deg N caloric summer half-year insolation (Gj m-2)
Tom made the point that Carbon Dioxide was "just plant food", and implied that it was harmless in the atmosphere. He believes that cycles of ice ages and warmer periods were generated by the factors relating to the Earths position and the Sun.
This brought the presentation back to Tom's area of employment as an agricultural economist, and his belief that our focus should be on adapting to the changes that are occurring,