6 research outputs found
The importance of land use change in the environmental balance of biofuels
The potential of first generation biofuels to mitigate climate change is still largely
debated in the scientific and policy-making arenas. It is currently assessed through life
cycle assessment (LCA), a method for accounting for the greenhouse gas (GHG) emissions of
a given product from “cradle-to-grave”, which is widely used to aid decision making on
environmental issues. Although LCA is standardized, its application to biofuels leads to
inconclusive results often fraught by a high variability and uncertainty. This is due to
differences in quantifying the environmental impacts of feedstock production, and the
difficulties encountered when considering land use changes (LUC) effects. The occurrence
of LUC mechanisms is in part the consequence of policies supporting the use of biofuels in
the transport sector, which implicitly increases the competition between various possible
uses of land worldwide. Here, we review the methodologies recently put forward to include
LUC effects in LCAs, and examples from the US, Europe and France. These cross analysis
show that LCA needs to be adapted and combined to other tools such as economic modeling in
order to provide a more reliable assessment of the biofuels chains
The importance of land use change in the environmental balance of biofuels
The potential of first generation biofuels to mitigate climate change is still largely
debated in the scientific and policy-making arenas. It is currently assessed through life
cycle assessment (LCA), a method for accounting for the greenhouse gas (GHG) emissions of
a given product from “cradle-to-grave”, which is widely used to aid decision making on
environmental issues. Although LCA is standardized, its application to biofuels leads to
inconclusive results often fraught by a high variability and uncertainty. This is due to
differences in quantifying the environmental impacts of feedstock production, and the
difficulties encountered when considering land use changes (LUC) effects. The occurrence
of LUC mechanisms is in part the consequence of policies supporting the use of biofuels in
the transport sector, which implicitly increases the competition between various possible
uses of land worldwide. Here, we review the methodologies recently put forward to include
LUC effects in LCAs, and examples from the US, Europe and France. These cross analysis
show that LCA needs to be adapted and combined to other tools such as economic modeling in
order to provide a more reliable assessment of the biofuels chains
The importance of land use change in the environmental balance of biofuels
The potential of first generation biofuels to mitigate climate change is still largely debated in the scientific and policy-making arenas. It is currently assessed through life cycle assessment (LCA), a method for accounting for the greenhouse gas (GHG) emissions of a given product from "cradle-to-grave", which is widely used to aid decision making on environmental issues. Although LCA is standardized, its application to biofuels leads to inconclusive results often fraught by a high variability and uncertainty. This is due to differences in quantifying the environmental impacts of feedstock production, and the difficulties encountered when considering land use changes (LUC) effects. The occurrence of LUC mechanisms is in part the consequence of policies supporting the use of biofuels in the transport sector, which implicitly increases the competition between various possible uses of land worldwide. Here, we review the methodologies recently put forward to include LUC effects in LCAs, and examples from the US, Europe and France. These cross analysis show that LCA needs to be adapted and combined to other tools such as economic modeling in order to provide a more reliable assessment of the biofuels chains
Information provision by regulated public transport companies
We study the interaction between pricing, frequency of service and information provision
by public transport firms offering scheduled services, and we do so under various regulatory
regimes. The model assumes that users can come to the bus stop or rail station at random
or they can plan their trips; the fraction of users who plan their trips is endogenous
and depends on the frequency of service and on the quality of information provided. Four
institutional regimes are considered, reflecting various degrees of government regulation.
A numerical example illustrates the theoretical results. Findings include the following.
First, fare regulation induces the firm to provide less frequency and less information than
is socially optimal. Second, if information and frequency did not affect the number of planning
users a higher fare always induces the firm to raise both frequency and the quality of
information. With endogenous planning, however, this need not be the case, as the effect of
higher fares strongly depends on how frequency and information quality affect the number
of planners. Third, a profit-maximizing firm offers more information than a fare-regulated
firm. Fourth, if the agency regulates both the fare and the quality of information then more
stringent information requirements induce the firm to reduce frequency; this strongly limits
the welfare improvement of information regulation. Finally, of all institutional structures
considered, socially optimal fares, frequency and quality of information stimulate
passengers least to plan their trips, because the high frequency offered reduces the benefits
of trip planning
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SEIS: Insight’s Seismic Experiment for Internal Structure of Mars
By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars’ surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking’s Mars seismic monitoring by a factor of ∼2500 at 1 Hz and ∼200000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars’ surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of ∼3 at 40∘ epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution