While tourism and air transport are recovering from the impacts of the Covid pandemic, it seems timely to draw a synthetic view of future stakes combining the following topics: the greenhouse gas emissions scenarios for tourism, regarding which recent work has improved their understanding; the climatic impact of aviation, almost 60% of which is due to non-CO 2 emissions; alternative fuels (biofuels, E-fuels, hydrogen) and engine designs (fuel cells...) which are complex and controversial issues, and whose potentials should be assessed regarding their timing, environmental impacts, and their ability to meet long distance travel requirements. This paper analyses the extent to which the new options regarding fuels and engines can help decarbonize tourism and air transport. The answer is that they can partly contribute but do not render obsolete previous work on substitutions between types of tourism (short versus long distance...), between transport modes (ground transport versus air), length of stay, etc. Following this step, the paper deals with the position of aviation players and the type of arguments they use. We conclude on the necessity to make strategic choices among the options to avoid wasting investments.
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At this moment, no method is available to objectively estimate the temperature to which skeletal remains have been exposed during a fire. Estimating this temperature can provide crucial information in a legal investigation. Exposure of bone to heat results in observable and measurable changes, including a change in colour. To determine the exposure temperature of experimental bone samples, heat related changes in colour were systemically studied by means of image analysis. In total 1138 samples of fresh human long bone diaphysis and epiphysis, varying in size, were subjected to heat ranging from room temperature to 900 °C for various durations and in different media. The samples were scanned with a calibrated flatbed scanner and photographed with a Digital Single Lens Reflex camera. Red, Green, Blue values and Lightness, A-, and B-coordinates were collected for statistical analysis. Cluster analysis showed that discriminating thresholds for Lightness and B-coordinate could be defined and used to construct a model of decision rules. This model enables the user to differentiate between seven different temperature clusters with relatively high precision and accuracy. The proposed decision model provides an objective, robust and non-destructive method for estimating the exposure temperature of heated bone samples.
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