Long-range Forecasting (continued)

He told us that investigators using the historical record claimed to have found evidence of significant climatic variations in the period 4000 BC to 1400 AD while others had attached significance to the periods of advance and recession of glaciers in more recent years.

Willet drew attention to suggestions that ice ages were caused by tectonic movements in the Earth's crust or by variations in the eccentricity of the orbit of the Earth around the sun, and variations in the axis of the Earth's rotation.

I admired the dispassionate manner in which Willet reviewed the evidence. He emphasised the considerable effort expended in investigating climatic fluctuations but avoided an over-optimistic assessment of the progress made in understanding these fluctuations.

His article on forecasting in the Compendium of Meteorology (Willet, 1951) is an example of his cautious approach in assessing the validity of the many theories on reasons for the various time scales of fluctuations in weather and climate. In 1951 his lectures emphasised that the methods of forecasting available to the meteorologist at that time were not likely to improve significantly until an observational program was established enabling synoptic analysis to be extended to a global scale. He suggested that such a program would require an international centre staffed by talented research workers, testing the validity of theories by using synoptic analysis on a global scale.

Bureau of Meteorology