Assessing the environmental impacts of production- and consumption-side measures in sustainable agriculture intensification in the European Union

Sustainable agricultural intensification (SI) is an important strategy to respond to the combined challenge of achieving food security and providing public goods and ecosystem services to society, including mitigation and adaptation of climate change. Sustainable intensification includes a wide range of measures at both the supply and demand-side of agricultural production. However, currently, it is unclear what are the most effective and priority measures. This study assesses the potential of different SI measures for reducing GHG (greenhouse gas) emissions and increasing land use efficiency in the European Union's agriculture sector. A scenario approach was combined with life cycle analysis to quantify the environmental impacts of a number of different SI measures. The sustainable intensification measures assessed in this study are: 1) changing human diet; 2) using food waste in livestock diets; 3) shifting from monoculture cropping to crop rotation, and, 4) incorporating crop residues into the soil. The results reveal that the studied SI measures have the potential to increase land use savings, ranging from 0.06 to 3.32 m2/person/day, while GHG emission savings ranging from 71 to 1872 g CO2-eq/person/day can be achieved at EU level. Among these SI measures, changing human diet showed a remarkably high reduction of environmental impacts. On the contrary, increased GHG emission savings in the other SI measures (i.e. crop residue incorporation in the field and replacing soybean meal in conventional feed by food waste-based feed) are counter effected by increased GHG emissions in the energy sector due to reduction of feedstock availability for bioenergy production. The approach used in this study allows the assessment of both the production and consumption-side SI measures and allows the identification of the most effective SI measures and their potential trade-offs

2+1 gravity and Doubly Special Relativity

It is shown that gravity in 2+1 dimensions coupled to point particles provides a nontrivial example of Doubly Special Relativity (DSR). This result is obtained by interpretation of previous results in the field and by exhibiting an explicit transformation between the phase space algebra for one particle in 2+1 gravity found by Matschull and Welling and the corresponding DSR algebra. The identification of 2+1 gravity as a $DSR$ system answers a number of questions concerning the latter, and resolves the ambiguity of the basis of the algebra of observables. Based on this observation a heuristic argument is made that the algebra of symmetries of ultra high energy particle kinematics in 3+1 dimensions is described by some DSR theory.Comment: 8 pages Latex, no figures, typos correcte

Coset Space Dimensional Reduction and Wilson Flux Breaking of Ten-Dimensional N=1, E(8) Gauge Theory

We consider a N=1 supersymmetric E(8) gauge theory, defined in ten dimensions and we determine all four-dimensional gauge theories resulting from the generalized dimensional reduction a la Forgacs-Manton over coset spaces, followed by a subsequent application of the Wilson flux spontaneous symmetry breaking mechanism. Our investigation is constrained only by the requirements that (i) the dimensional reduction leads to the potentially phenomenologically interesting, anomaly free, four-dimensional E(6), SO(10) and SU(5) GUTs and (ii) the Wilson flux mechanism makes use only of the freely acting discrete symmetries of all possible six-dimensional coset spaces.Comment: 45 pages, 2 figures, 10 tables, uses xy.sty, longtable.sty, ltxtable.sty, (a shorter version will be published in Eur. Phys. J. C

Randomized clinical trial and follow-up study of cost-effectiveness of laparoscopic versus conventional Nissen fundoplication

Background: Laparoscopic Nissen fundoplication (LNF) has essentially replaced its conventional open counterpart (CNF). An economic evaluation of LNF compared with CNF based on prospective data with adequate follow-up is lacking. Methods: Data from two consecutive studies (a randomized clinical trial (RCT) of 57 patients undergoing LNF and 46 undergoing CNF that was terminated prematurely, and a follow-up study of 121 consecutive patients with LNF) were combined to determine incremental cost-effectiveness 1 year after surgery. Results: Mean operating time, reoperation rate and hospital costs of LNF were lower in the second series. The mean overall hospital cost per patient was E9126 for LNF and E6989 for CNF at 1 year in the initial RCT, and E7782 in the second LNF series. The success rate of both LNF and CNF at I year was 91 per cent in the RCT, and LNF was successful in 90.1 per cent in the second series. A cost reduction of E998 for LNF would cancel out the cost advantage of CNF. Similarly, if the reoperation rate after LNF decreased from 0.05 to below 0.008 and/or if the mean duration of sick leave after LNF was reduced from 67.2 to less than 61.1 days, the procedure would become less expensive than CNF. Complications, reoperation rate and quality of life after both operations were similar. Conclusion: Including reinterventions, the outcome at 1 year after LNF and CNF was similar. In a well organized setting with appropriate expertise, the cost advantage of CNF may be neutralized

Transport impacts on atmosphere and climate: Aviation

Aviation alters the composition of the atmosphere globally and can thus drive climate change and ozone depletion. The last major international assessment of these impacts was made by the Intergovernmental Panel on Climate Change (IPCC) in 1999. Here, a comprehensive updated assessment of aviation is provided. Scientific advances since the 1999 assessment have reduced key uncertainties, sharpening the quantitative evaluation, yet the basic conclusions remain the same. The climate impact of aviation is driven by long-term impacts from CO2 emissions and shorter-term impacts from non-CO2 emissions and effects, which include the emissions of water vapour, particles and nitrogen oxides (NOx). The present-day radiative forcing from aviation (2005) is estimated to be 55 mW m−2 (excluding cirrus cloud enhancement), which represents some 3.5% (range 1.3–10%, 90% likelihood range) of current anthropogenic forcing, or 78 mW m−2 including cirrus cloud enhancement, representing 4.9% of current forcing (range 2–14%, 90% likelihood range). According to two SRES-compatible scenarios, future forcings may increase by factors of 3–4 over 2000 levels, in 2050. The effects of aviation emissions of CO2 on global mean surface temperature last for many hundreds of years (in common with other sources), whilst its non-CO2 effects on temperature last for decades. Much progress has been made in the last ten years on characterizing emissions, although major uncertainties remain over the nature of particles. Emissions of NOx result in production of ozone, a climate warming gas, and the reduction of ambient methane (a cooling effect) although the overall balance is warming, based upon current understanding. These NOx emissions from current subsonic aviation do not appear to deplete stratospheric ozone. Despite the progress made on modelling aviation's impacts on tropospheric chemistry, there remains a significant spread in model results. The knowledge of aviation's impacts on cloudiness has also improved: a limited number of studies have demonstrated an increase in cirrus cloud attributable to aviation although the magnitude varies: however, these trend analyses may be impacted by satellite artefacts. The effect of aviation particles on clouds (with and without contrails) may give rise to either a positive forcing or a negative forcing: the modelling and the underlying processes are highly uncertain, although the overall effect of contrails and enhanced cloudiness is considered to be a positive forcing and could be substantial, compared with other effects. The debate over quantification of aviation impacts has also progressed towards studying potential mitigation and the technological and atmospheric tradeoffs. Current studies are still relatively immature and more work is required to determine optimal technological development paths, which is an aspect that atmospheric science has much to contribute. In terms of alternative fuels, liquid hydrogen represents a possibility and may reduce some of aviation's impacts on climate if the fuel is produced in a carbon-neutral way: such fuel is unlikely to be utilized until a ‘hydrogen economy’ develops. The introduction of biofuels as a means of reducing CO2impacts represents a future possibility. However, even over and above land-use concerns and greenhouse gas budget issues, aviation fuels require strict adherence to safety standards and thus require extra processing compared with biofuels destined for other sectors, where the uptake of such fuel may be more beneficial in the first instance