James Rodger Fleming

Radiative Effects of Cirrus Clouds

Abstract The divergence of net radiation in a tropical atmosphere with cirrus clouds has been examined in terms of two bulk radiative properties of the cloud: effective shortwave optical thickness τ* and broad–band infrared emissivity ϵ&ast. The effective shortwave optical thickness of the cirrus cloud is the primary factor controlling the radiative energy budget at the earths surface while the clouds broad–band infrared emissivity is the primary factor influencing the heat budget of the atmosphere. The net radiative energy budget of the tropical atmosphere over an ocean surface in the presence and absence of a cirrus cloud has been examined. The total net radiative energy at the top of the atmosphere is relatively unchanged from the clear sky value by the presence of a cirrus cloud layer while the surface energy budget shows a significant decrease in the shortwave component. The total net radiative energy loss of the atmosphere when a cirrus layer is present is shown to be 22 to 78% of the loss from a ...

Joseph Fourier, the 'greenhouse effect', and the quest for a universal theory of terrestrial temperatures

The central role that the theory of terrestrial temperatures played in Fouriers mathematical physics has not received the attention it deserves from historians, although his cryptic allusions to the heating of a greenhouse, taken out of context, have been widely cited by subsequent authors.

Detection of compounds that rescue Rab1-synuclein toxicity.

Recent studies implicate a disruption in Rab-mediated protein trafficking as a possible contributing factor to neurodegeneration in Parkinsons disease (PD). Misfolding of the neuronal protein alpha-synuclein (asyn) is implicated in PD. Overexpression of asyn results in cell death in a wide variety of model systems, and in several organisms, including yeast, worms, flies, and rodent primary neurons, this toxicity is suppressed by the overproduction of Rab proteins. These and other findings suggest that asyn interferes with Rab function and provide new avenues for PD drug discovery. This chapter describes two assay formats that have been used successfully to identify small molecules that rescue asyn toxicity in yeast. The 96-well format monitors rescue by optical density and is suitable for screening thousands of compounds. A second format measures viable cells by reduction of the dye alamarBlue, a readout that is compatible with 96-, 384-, and 1536-well plates allowing the screening of large libraries (>100,000 compounds). A secondary assay to eliminate mechanistically undesirable hits is also described.

Climate Since A.D. 1500

The editors of this impressive volume are to be congratulated for gathering a stellar collection of thirty-three authoritative papers on the most recent period of climate history. In addition to providing thirty-three pages of introduction and conclusion, the editors also coauthored two important papers for the volume. This book will become a standard reference for the interdisciplinary climatic change community. Climate Since A.D. 1500 is divided into four sections: documentary evidence, dendroclimatic evidence, ice-core evidence, and forcing factors. In all, there are twelve papers using documentary evidence, eleven using dendroclimatic evidence, five on ice-core evidence, and three on forcing factors. The documentary papers cover Canada, the northeastern United States, Ireland, central Europe, northern Italy, the former Soviet Union, China, and Japan, with temporal coverage ranging from 1500 to very near the present.

T. C. Chamberlin and H2O climate feedbacks: A voice from the past

The interaction of positive and negative climate feedbacks has become a central issue for the global change science community. With many expecting surface air temperatures to rise several degrees due to increases in anthropogenic greenhouse gases, the response of H2O (water vapor, liquid, solid) is critical. Will higher temperatures and increased evaporation lead to an enhanced greenhouse effect, especially over the tropical oceans, or will increased cloudiness effectively cap the increase in temperatures? [see Ramanathan and Collins, 1991, 1992; Stephens and Slingo, 1992]. “Greenhouse Warming and Cloud Thermostats” is the name of a talk to be given by V. Ramanathan during the Atmospheric Sciences Section luncheon at the AGU 1992 Fall Meeting on December 8. This topic invites comparison between the current H2O feedback hypotheses and work begun almost a century ago by the celebrated geologist Thomas Chrowder Chamberlin (1843–1928) at the University of Chicago [Gillispie, 1970–1980; Schultz, 1976]. Briefly, here are some of Chamberlins ideas on the roles of water vapor and clouds.

Arrhenius and current climate concerns: Continuity or a 100‐year gap?

In a paper presented to the Stockholm Physical Society in 1895 and published the following year, Svante Arrhenius demonstrated that variations of atmospheric CO2 concentration could have a very great effect on the overall heat budget and surface temperature of the planet. It would be a mistake, however, to consider this work as a direct forerunner of current climate concerns [Uppenbrink, 1996]. Arrhenius, who has recently gained renewed attention as the “father” of the theory of the greenhouse effect, held assumptions and produced results that are not continuous with present-day climate research. For example, he suggested that increasing the carbon dioxide content of the atmosphere by burning fossil fuels might be beneficial, making the Earths climates warmer and “more equable,” stimulating plant growth, and providing more food for a larger population [Arrhenius, 1908]. Arrheniuss view of the potentially beneficial effects of carbon dioxide emissions differs radically from current concerns over the harmful effects of a global warming caused by industrial activity and deforestation [Fleming, 1998].

Carl-Gustaf Rossby: Theorist, institution builder, bon vivant

Best known for discovering the planetary waves that now bear his name, the Swede was arguably the most influential and innovative meteorologist of the 20th century.

T. C. Chamberlin, Climate Change, and Cosmogony

Abstract This paper examines the life and work of T. C. Chamberlin, a prominent glacial geologist who developed an interest in interdisciplinary earth science. His work on the geological agency of the atmosphere informed his understanding of climate change and other terrestrial phenomena and led him to propose a new theory of the formation of the Earth and the solar system. Chamberlins graduate seminar at the University of Chicago in 1896 contained all the themes that informed his research programme over the next three decades. These included the carbon dioxide theory of climate change in its relationship to diastrophism and oceanic circulation, the role of water vapour feedbacks in the climate system, and the relationship between multiple glaciations, the climate system, and the formation of the planet.

Charles Lyell and climatic change: speculation and certainty

Abstract In the first edition of the Principles of Geology, Charles Lyell announced his theory of the geographical determination of climate and speculated on possible climatic changes during the geological and historical past. In light of the subsequent discovery of ice ages, the proliferation of theories of climatic change, and the great climate debates of his time. Lyell’s theory remained remarkably stable. This paper examines Lyell’s appropriation, modification and rejection of the views of his contemporaries. It provides perspectives on elite and popular ideas of climate and climatic change from the late eighteenth century to 1875, examines Lyell’s position on climatic change in geological and historical times, and explores in some detail the mutual influences of Lyell and James Croll, the proponent of an astronomical theory of ice ages.

Technology and Environmental Determinisms

According to Merritt Roe Smith and Leo Marx, technological determinisms may be arrayed on a spectrum from &dquo;hard&dquo; to &dquo;soft.&dquo; At one extreme, machines or artifacts are seen as active agents of historical change. Inventions (such as the automobile, the atomic bomb, or robots) have inevitable consequences (for example, suburbia, the garrison state, or unemployment). Technology dictates the future, either bright with choice and progress or a totalitarian hell, the product of necessity’s iron hand.