An Attempt To Frame A Working Hypothesis Of The Cause Of Glacial Periods On Atmospheric Basis

The Rejection of Continental Drift

In the early twentieth century, American earth scientists were united in their opposition to the new--and highly radical--notion of continental drift, even going so far as to label the theory "unscientific." Some fifty years later, however, continental drift was heralded as a major scientific breakthrough and today it is accepted as scientific fact. Why did American geologists reject so adamantly an idea that is now considered a cornerstone of the discipline? And why were their European colleagues receptive to it so much earlier? This book, based on extensive archival research on three continents, provides important new answers while giving the first detailed account of the American geological community in the first half of the century. Challenging previous historical work on this episode, Naomi Oreskes shows that continental drift was not rejected for the lack of a causal mechanism, but because it seemed to conflict with the basic standards of practice in American geology. This account provides a compelling look at how scientific ideas are made and unmade.

Palaeoclimates and their Modelling

The climate of the Earth has undergone many changes and for those times when geologic data are widespread and abundant the Mesozoic appears to have been one of the warmest intervals. This was a time during which the single continent Pangea disintegrated into continental units similar to those of today, a time when there were no significant polar ice caps and sea level was generally much higher than at the present time, and a time when dinosaurs apparently dominated terrestrial faunas and the flowering plants evolved. Understanding this alien world, ancestral to ours, is intrinsically interesting, intellectually challenging, and offers opportunities for more effective targeting of sites where commercially important geological resources may be found. It also provides critical insights into the operation of coupled Earth systems (biospheric, atmospheric, hydrospheric and geospheric) under extreme 'greenhouse' conditions, and therefore may have relevance to possible future global change. Our intention in organizing this Discussion Meeting was to bring together those who gather and interpret geologic data with those who model global climates from first principles. The community of workers who study the Quaternary have made significant advances by integrating and comparing palaeodata and climate model experiments. Although we have focused not on the Quaternary 'icehouse' but on the Mesozoic 'hothouse' climate we are well aware that approaches used in the study of the Quaternary may have relevance to earlier times.

A Treatise on Metamorphism