Energy for cities: Supply, demand and infrastructure investment

© 2017, Springer International Publishing AG. Energy is essential to all activities in all regions of a country. However the density of energy use in, and our economic dependence on, cities means that it is more critical for urban areas. Nevertheless we suggest that the provision of energy for urban areas cannot be considered separately from the national context. We will demonstrate how to assess the ability of a nation to invest in energy infrastructure for the benefit of cities. Our approach exploits data sets which are available in most industrialised countries, and we select two quite different case studies to illustrate our method: the Colombia (Bogota) and UK (London). Our focus for energy sustainability in cities is quality of life and reduced fossil-fuel emissions. We will show that the main target for cities should be to improve air quality and reduce energy demand by improving energy efficiency

High resolution exposure modelling of heat and air pollution and the impact on mortality

Background: Elevated temperature and air pollution have been associated with increased mortality. Exposure to heat and air pollution, as well as the density of vulnerable groups varies within cities. The objective was to investigate the extent of neighbourhood differences in mortality risk due to heat and air pollution in a city with a temperate maritime climate. Methods: A case-crossover design was used to study associations between heat, air pollution and mortality. Different thermal indicators and air pollutants (PM10, NO2, O-3) were reconstructed at high spatial resolution to improve exposure classification. Daily exposures were linked to individual mortality cases over a 15 year period. Results: Significant interaction between maximum air temperature (Ta-max) and PM10 was observed. During "summer smog" days (Ta-max > 25 degrees C and PM10 > 50 mu g/m(3)), the mortality risk at lag 2 was 7% higher compared to the reference (Ta-max 15 degrees C and PM10 15 mu g/m(3)). Persons above age 85 living alone were at highest risk. Conclusion: We found significant synergistic effects of high temperatures and air pollution on mortality. Single living elderly were the most vulnerable group. Due to spatial differences in temperature and air pollution, mortality risks varied substantially between neighbourhoods, with a difference up to 7%. (C) 2016 Elsevier Ltd. All rights reserved

Biosphere-atmosphere exchange of ammonia

Substantial progress has been made in the last eight years in the understanding and quantification of ammonia exchange between the atmosphere and biosphere. Much of the work has been linked to the joint EC/EUROTRAC subproject BIATEX (BIosphere ATmosphere EXchange), which has served as the main European forum for work in this area. In the mid-1980s there was still much confusion and uncertainty over the rate and direction of ammonia fluxes with different ecosystems; although the results of isolated studies were available, there was no clear overview of the key factors affecting ammonia fluxes. Work since that time has highlighted the dominant effects of ecosystem type and management, as well as humidity and wetness, on ammonia exchange. Ammonia is a key component of plant metabolism, so that ammonia emission may occur from plants in relation to nitrogen nutrition and plant growth stage. In contrast, ammonia is highly soluble and may be efficiently captured by leaf cuticles and surface w etness allowing large deposition velocities. The consequence is that ammonia exchange is bi-directional over agricultural ecosystems, though for most semi-natural ecosystems dry deposition dominates, being a significant component of the total atmospheric nitrogen input. The work within BIATEX has focused in more detail on the processes controlling these differences and, using the results of both micrometeorological and controlled environment measurements, has developed new models that are able to provide the synthesis necessary to predict ammonia fluxes. Long term and regional estimates of ammonia net exchange are still uncertain, though the models developed now provide the necessary framework to guide future measurements