Development of Transportation Infrastructure in the Context of Economic Growth

Developed road infrastructure is an essential factor facilitating and accelerating economic growth, which will in turn enable the addition of more roads. At the same time, the marginal benet of adding roads to a large stock of existing capacity might be diminishing. It is thus evident that the co-evolution of economic output and road infrastructure is rather intricate and deserves special attention. The model developed in this paper therefore investigates the interdependency between a country's economic growth and the development of transportation infrastructure in this country. To this end, a co-evolutionary perspective is developed, where the mutual inuence of the rate of economic growth and the capacity of transportation infrastructure are explicitly taken into account. This approach enables us to set up an optimal control problem, where the optimal investment rate is determined considering the co-evolutionary dynamics of GDP growth and capacity expansion. This model forms a comprehensive framework for understanding the underlying dynamics and the patterns of economic growth in relation to transport infrastructure. We nd an analytical solution for the innite horizon problem, where the control turns out to be a constant. The steady state is shown to depend crucially on the rate of physical decay of roads, which we think can be interpreted as an index of quality, and the speed of adjustment, at which the economy moves along a trajectory. Testing the model for the data of two countries, France and Finland, illustrates the usefulness of such an approach to real world problems and possibly policy recommendation, where the model would have to be adapted to the peculiarities of each country or region to make precise statements

Forest-based bioenergy in the Eurasian context

This study analyses the Russian forest biomass-based bioenergy sector. It is shown that presently - although given abundant resources - the share of heat and electricity from biomass is very minor. With the help of 2 IIASA models, future green-field bioenergy plants are identified in a geographically explicit way. Results indicate that by only using 3.3% of the total wood removals, twice as much heat and electricity than presently available from biomass could be generated. Furthermore, there is a multitude of additional co-benefits quantified for the socio-economic sector such as green jobs linked to bioenergy

Negative Emissions and Interactions with other Mitigation Options: A Bottom-up Methodology for Indonesia

BECCS (here the combination of forest-based bioenergy with carbon capture and storage) is seen as a promising tool to deliver the large quantities of negative emissions needed to comply with ambitious climate stabilization targets. However, a land-based mitigation option such as large-scale bioenergy production (without CCS) might interfere with other land-based mitigation options popular for their large co-benefits such as reduced emissions from deforestation and degradation (REDD+). We develop a systems approach to identify and quantify possible trade-offs between REDD+ and BECCS with the help of remote sensing and engineering modeling and apply this for illustration to Indonesia. First results indicate that prioritizing REDD+ does imply that there the BECCS potential remains limited. Further research is needed to take into account opportunities where the two options could be deployed synergistically, capitalizing on co-benefits. BECCS and REDD+ must be evaluated from a portfolio perspective, as estimating their potentials independently will not take such opportunities into account

Climate change induced transformations of agricultural systems: insights from a global model

Climate change might impact crop yields considerably and anticipated transformations of agricultural systems are needed in the coming decades to sustain affordable food provision. However, decision-making on transformational shifts in agricultural systems is plagued by uncertainties concerning the nature and geography of climate change, its impacts, and adequate responses. Locking agricultural systems into inadequate transformations costly to adjust is a significant risk and this acts as an incentive to delay action. It is crucial to gain insight into how much transformation is required from agricultural systems, how robust such strategies are, and how we can defuse the associated challenge for decision-making. While implementing a definition related to large changes in resource use into a global impact assessment modelling framework, we find transformational adaptations to be required of agricultural systems in most regions by 2050s in order to cope with climate change. However, these transformations widely differ across climate change scenarios: uncertainties in large-scale development of irrigation span in all continents from 2030s on, and affect two-thirds of regions by 2050s. Meanwhile, significant but uncertain reduction of major agricultural areas affects the Northern Hemisphere's temperate latitudes, while increases to non-agricultural zones could be large but uncertain in one-third of regions. To help reducing the associated challenge for decision-making, we propose a methodology exploring which, when, where and why transformations could be required and uncertain, by means of scenario analysis

Chemo- and Thermosensory Responsiveness of Grueneberg Ganglion Neurons Relies on Cyclic Guanosine Monophosphate Signaling Elements

Neurons of the Grueneberg ganglion (GG) in the anterior nasal region of mouse pups respond to cool temperatures and to a small set of odorants. While the thermosensory reactivity appears to be mediated by elements of a cyclic guanosine monophosphate (cGMP) cascade, the molecular mechanisms underlying the odor-induced responses are unclear. Since odor-responsive GG cells are endowed with elements of a cGMP pathway, specifically the transmembrane guanylyl cyclase subtype GC-G and the cyclic nucleotide-gated ion channel CNGA3, the possibility was explored whether these cGMP signaling elements may also be involved in chemosensory GG responses. Experiments with transgenic mice deficient for GC-G or CNGA3 revealed that GG responsiveness to given odorants was significantly diminished in these knockout animals. These findings suggest that a cGMP cascade may be important for both olfactory and thermosensory signaling in the GG. However, in contrast to the thermosensory reactivity, which did not decline over time, the chemosensory response underwent adaptation upon extended stimulation, suggesting that the two transduction processes only partially overlap. Copyright (C) 2011 S. Karger AG, Base