Evaluation of biospheric components in Earth system models using modern and palaeo-observations: the state-of-the-art

Earth system models (ESMs) are increasing in complexity by incorporating more processes than their predecessors, making them potentially important tools for studying the evolution of climate and associated biogeochemical cycles. However, their coupled behaviour has only recently been examined in any detail, and has yielded a very wide range of outcomes. For example, coupled climate–carbon cycle models that represent land-use change simulate total land carbon stores at 2100 that vary by as much as 600 Pg C, given the same emissions scenario. This large uncertainty is associated with differences in how key processes are simulated in different models, and illustrates the necessity of determining which models are most realistic using rigorous methods of model evaluation. Here we assess the state-of-the-art in evaluation of ESMs, with a particular emphasis on the simulation of the carbon cycle and associated biospheric processes. We examine some of the new advances and remaining uncertainties relating to (i) modern and palaeodata and (ii) metrics for evaluation. We note that the practice of averaging results from many models is unreliable and no substitute for proper evaluation of individual models. We discuss a range of strategies, such as the inclusion of pre-calibration, combined process- and system-level evaluation, and the use of emergent constraints, that can contribute to the development of more robust evaluation schemes. An increasingly data-rich environment offers more opportunities for model evaluation, but also presents a challenge. Improved knowledge of data uncertainties is still necessary to move the field of ESM evaluation away from a "beauty contest" towards the development of useful constraints on model outcomes.

Effects of gamma ray bursts in Earth`s biosphere

We continue former work on the modeling of potential effects of Gamma Ray Bursts on Phanerozoic Earth. We focus on global biospheric effects of ozone depletion and model the spectral reduction of light by NO(2) formed in the stratosphere. We also illustrate the current complexities involved in the prediction of how terrestrial ecosystems would respond to this kind of burst. We conclude that more biological field and laboratory data are needed to reach even moderate accuracy in this modeling.

Trends, fads and futures : computers in learning in tertiary education, 1983-2002

ASCILITE, the Australasian Society for Computers in Learning in Tertiary Education, is a professional society focusing on computers in learning in tertiary education that has been sponsoring conferences for its membership since 1986. Prior to this, three earlier conferences formed the genesis of ASCILITE. Over that period there have been significant changes in pedagogy and technology but few attempts, if any, have been made to analyse the ways in which conference proceedings have reflected these changes and shifts. The purpose of this research paper is to review the ASCILITE proceedings and provide an analysis of “trends, fads and futures” to reflect on past initiatives, propose potential directions and assist the society identify strategic directions. In addition, the analysis will provide a basis from which further research can be justified in terms of better understanding “computers in learning in tertiary education”.

The use of laptop computers in programming lectures

This research explores the effect of the use of laptop computers on students’ learning experiences during lectures. Our methodology involves embedding laptops with visualization software as a learning aid during lectures. We then employ a framework of seven principles of good practice in higher education to evaluate the impact of the use of laptop computers on the learning experience of computer programming students. Overall, we found that students were highly motivated and supportive of this innovative use of laptop computers with lectures.