Impact of a potential 21st century “grand solar minimum” on surface temperatures and stratospheric ozone

We investigate the effects of a recently proposed 21st century Dalton minimum like decline of solar activity on the evolution of Earth's climate and ozone layer. Three sets of two member ensemble simulations, radiatively forced by a midlevel emission scenario (Intergovernmental Panel on Climate Change RCP4.5), are performed with the atmosphere-ocean chemistry-climate model AOCCM SOCOL3-MPIOM, one with constant solar activity, the other two with reduced solar activity and different strength of the solar irradiance forcing. A future grand solar minimum will reduce the global mean surface warming of 2 K between 1986–2005 and 2081–2100 by 0.2 to 0.3 K. Furthermore, the decrease in solar UV radiation leads to a significant delay of stratospheric ozone recovery by 10 years and longer. Therefore, the effects of a solar activity minimum, should it occur, may interfere with international efforts for the protection of global climate and the ozone layer.

Transient simulations of the carbon and nitrogen dynamics in northern peatlands: from the Last Glacial Maximum to the 21st century

The development of northern high-latitude peatlands played an important role in the carbon (C) balance of the land biosphere since the Last Glacial Maximum (LGM). At present, carbon storage in northern peatlands is substantial and estimated to be 500 ± 100 Pg C (1 Pg C = 1015 g C). Here, we develop and apply a peatland module embedded in a dynamic global vegetation and land surface process model (LPX-Bern 1.0). The peatland module features a dynamic nitrogen cycle, a dynamic C transfer between peatland acrotelm (upper oxic layer) and catotelm (deep anoxic layer), hydrology- and temperature-dependent respiration rates, and peatland specific plant functional types. Nitrogen limitation down-regulates average modern net primary productivity over peatlands by about half. Decadal acrotelm-to-catotelm C fluxes vary between −20 and +50 g C m−2 yr−1 over the Holocene. Key model parameters are calibrated with reconstructed peat accumulation rates from peat-core data. The model reproduces the major features of the peat core data and of the observation-based modern circumpolar soil carbon distribution. Results from a set of simulations for possible evolutions of northern peat development and areal extent show that soil C stocks in modern peatlands increased by 365–550 Pg C since the LGM, of which 175–272 Pg C accumulated between 11 and 5 kyr BP. Furthermore, our simulations suggest a persistent C sequestration rate of 35–50 Pg C per 1000 yr in present-day peatlands under current climate conditions, and that this C sink could either sustain or turn towards a source by 2100 AD depending on climate trajectories as projected for different representative greenhouse gas concentration pathways.

“Crye Fredome”? Medievalism and Twenty-First-Century Scottish National Identity

It is a well-documented fact that the Middle Ages have had a long history of instrumentalisation by nationalisms. 19th-century Eu¬rope in particular witnessed an origins craze during the process of nation-building. In the post-Shoah, post-modern West, on the other hand, we might expect this kind of medievalist master nar¬rative to have been consigned to the dustbin of history. And yet, as nationalism surges again in Europe, negotiations of national identi¬ties in medieval dress seem to have become fashionable once more. In order to come to terms with the fragmented and often contradictory presence of the Middle Ages in these discourses of national identity, I propose we consider medievalism a utilitarian product of the cultural memory. Rather than representing any ‘real’ Middle Ages, then, medievalism tailors available knowledge of the medieval past to the diverse social needs and ideologies of the present. This paper looks at a selection of Scottish examples of present-day medievalism in an attempt to investigate, in particular, the place of the medieval Wars of Scottish Independence in contemporary negotiations of ‘Scottishness’. Both the relationships envisioned between self and other and the role played by ‘the land’ in these cultural, social and political instances of national introspection offer starting points for critical inquiry. Moreover, the analysis of a scholarly intervention in the run-up to the 2014 Scottish independence referendum indicates an intriguing dialogue of academic and non-academic voices in the context of Scottish medievalist cultural memory. We thus find a wide array of uses of the Scottish Middle Ages, some of which feed into the burgeoning nationalism of recent years, while others offer more pensive and ambivalent answers to the question of what it means to be Scottish in the 21st century.