Degrading permafrost can alter ecosystems, damage infrastructure, and release enough carbon dioxide (CO 2 ) and methane (CH 4 ) to influence global climate. The permafrost carbon feedback (PCF) is the amplification of surface warming due to CO 2 and CH 4 emissions from thawing permafrost. An analysis of available estimates PCF strength and timing indicate 120 ± 85 Gt of carbon emissions from thawing permafrost by 2100. This is equivalent to 5.7 ± 4.0% of total anthropogenic emissions for the Intergovernmental Panel on Climate Change (IPCC) representative concentration pathway (RCP) 8.5 scenario and would increase global temperatures by 0.29 ± 0.21°C or 7.8 ± 5.7%. For RCP4.5, the scenario closest to the 2°C warming target for the climate change treaty, the range of cumulative emissions in 2100 from thawing permafrost decreases to between 27 and 100 Gt C with temperature increases between 0.05 and 0.15°C, but the relative fraction of permafrost to total emissions increases to between 3% and 11%. Any substantial warming results in a committed, long-term carbon release from thawing permafrost with 60% of emissions occurring after 2100, indicating that not accounting for permafrost emissions risks overshooting the 2°C warming target. Climate projections in the IPCC Fifth Assessment Report (AR5), and any emissions targets based on those projections, do not adequately account for emissions from thawing permafrost and the effects of the PCF on global climate. We recommend the IPCC commission a special assessment focusing on the PCF and its impact on global climate to supplement the AR5 in support of treaty negotiation.

This book traces the intellectual life of the Kingdom of Italy, the area in which humanism began in the mid thirteenth century, a century or more before exerting its influence on the rest of Europe. Covering a period of over four and a half centuries, this study offers the first integrated analysis of Latin writings produced in the area, examining not only religious, literary, and legal texts. Ronald G. Witt characterizes the changes reflected in these Latin writings as products of the interaction of thought with economic, political, and religious tendencies in Italian society as well as with intellectual influences coming from abroad. His research ultimately traces the early emergence of humanism in northern Italy in the mid thirteenth century to the precocious development of a lay intelligentsia in the region, whose participation in the culture of Latin writing fostered the beginnings of the intellectual movement which would eventually revolutionize all of Europe.

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In the almost forty years since he first enunciated his thesis, Paul O. Kristeller's view that the Italian humanists were essentially rhetoricians has found wide acceptance. His analysis of the humanist movement, however, indicates that he includes among the humanists' interests the four other disciplines comprising, along with rhetoric, the studia humanitatis: grammar, poetry, history, and moral philosophy. His decision to characterize the humanists as rhetoricians rather than as grammarians, poets, historians, or moral philosophers derives from his interpretation of the professional role played by the humanists in their society. For Kristeller the humanists performed the same professional functions in their world as the medieval dictatores did in theirs. Both groups were primarily teachers of rhetoric and chancery officials, and both devoted a substantial portion of their creative efforts to composing in two literary genres, the epistle and the oration.

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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. The University of Chicago Press and Renaissance Society of America are collaborating with JSTOR to digitize, preserve and extend access to Renaissance Quarterly. HE Italian humanists of the fourteenth century did -W; ) more than reintegrate the pursuit of eloquence with the concern for ethics, two interests united in the dis-~~' 'X6& cipline of rhetoric since the time of Cicero but separated in practice by thirteenth-century specialists of ars dictaminis in Italy.1 Rather their achievement lay in nothing less than Christianizing the European medieval rhetorical tradition. They accomplished this by expressing in terms of those central fields of rhetoric, ethics, and history an appreciation of the distinction between the culture of the ancient world based on human reason and Christian society founded on revealed truth.2 While not denying the ultimate influence of God upon human history, Petrarch, Boccaccio, and Salutati (at least in his later life) tended to emphasize the natural character of ancient society and thus to secularize its history and achievements. Such an understanding of the break in continuity encouraged these humanists to construct an ethic which was consciously Christian while utilizing the works of pagan writers as building blocks.Crucial to this effort at distinction was proper understanding of the conception of the poeta theologus. As this study intends to show, all three fourteenth-century writers eventually succeeded in defending the sacral character of ancient poetry, which in their own eyes gave it nobility, without having to resort to medieval arguments for a direct divine influence acting on the poet or for a secret tradition of divine truth initially derived from God's Revelation. Although the ancient * I would like to express my appreciation to Hans Baron and Marcel Tetel who read this article in its early drafts.1 Helene Wieruszowski, Politics and Culture in Medieval Spain and Italy, Storia e letteratura, 12 (Rome, 1971), p. 373.2 What Aquinas accomplished for philosophy by defining the limits of natural reason and working out the implications, Petrarch in effect did for rhetoric. Twelfth-century rhetoricians likeJohn of Salisbury and Pierre de Blois were apparently unable to integrate pagan ethical doctrines into a Christian framework. Thus Christian and pagan ideas lay side by side in their writings.[ 538 ] SALUTATI AND THE POETA THEOLOGUS poets frequently expressed theological truths, these were truths accessible to natural reason. Whereas the validity of this characterization of Petrarch and Boccaccio can easily be demonstrated by reference to their work, Salutati's thoughts on the subject are more difficult to define because he changed his mind in ...

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