The geography of urban greenhouse gas emissions in Asia: A regional analysis

This paper aims to advance two objectives: (1) identify and explore greenhouse gas emissions from urban areas in Asia at the regional level; and (2) explore covariates of urban greenhouse gas emissions. We use the Emissions Database for Global Atmospheric Research estimates for carbon dioxide, methane, nitrous oxide, and sulfur hexafluoride from 14 source activities for the year 2000, which are allocated on a 1/10° global grid. We extract emissions for 3535 urban extents all with populations over 50,000, accounting for approximately 91% of the region's urban population. We use regression analysis to associate emissions with urban area and growth, economic, and biophysical characteristics. Our findings suggest that urban areas account for between 30 and 38% of total anthropogenic greenhouse gas emissions for the region and that emission per capita averages from urban areas are lower than those at the national level. Important covariates for total urban greenhouse gas emissions include population size, density and growth rate, income per capita, development status and elevation. This is a first and preliminary assessment of regional baseline trends using these data and this top-down analysis.     

Urban-waterfront developments: a geographic problem in search of a model

A modified version of the economic rent model is applied to the significant urban-waterfront changes which have characterized most European and North American port cities during the twentieth century. The model is at this stage conceptual, although supported by case studies, and employs elements which are characteristic of the majority of waterfront renewal literature. The model addresses four different conditions, three of which trace the evolution which has characterized the traditional inner-city port. The first analyzes the conditions prevailing prior to the late 1950s, when most ocean cargo still used the traditional harbor. The second application of the model relates to the dynamic changes which started in the late 1950s and lasted approximately 20 years, a period in which many piers and warehouses were abandoned and destroyed. The urban-waterfront renewal efforts which have occurred in both Europe and North America are analyzed in the third phase, which emphasizes boundary changes and potential and real economic rent windfalls accruing to landowners in the path of or adjacent to proposed urban-waterfront renewal efforts. The final application of the model reviews the impact on both economic rents and land uses of improvements to the shore and nearshore marine environment.     

The 1991 eruption of Hekla,Iceland

The eruption that started in the Hekla volcano in South Iceland on 17 January 1991, and came to an end on 11 March, produced mainly andesitic lava. This lava covers 23 km² and has an estimated volume of 0.15 km³. This is the third eruption in only 20 years, whereas the average repose period since 1104 is 55 years. Earthquakes, as well as a strain pulse recorded by borehole strainmeters, occurred less than half an hour before the start of the eruption. The initial plinian phase was very short-lived, producing a total of only 0.02 km³ of tephra. The eruption cloud attained 11.5 km in height in only 10 min, but it became detached from the volcano a few hours later. Several fissures were active during the first day of the eruption, including a part of the summit fissure. By the second day, however, the activity was already essentially limited to that segment of the principal fissure where the main crater subsequently formed. The average effusion rate during the first two days of the eruption was about 800 m³ s^–1. After this peak, the effusion rate declined rapidly to 10–20 m³ s^–1, then more slowly to 1 m³ s^–1, and remained at 1–12 m³ s^–1 until the end of the eruption. Site observations near the main crater suggest that the intensity of the volcanic tremor varied directly with the force of the eruption. A notable rise in the fluorine concentration of riverwater in the vicinity of the eruptive fissures occurred on the 5th day of the eruption, but it levelled off on the 6th day and then remained essentially constant. The volume and initial silica content of the lava and tephra, the explosivity and effusion rate during the earliest stage of the eruption, as well as the magnitude attained by the associated earthquakes, support earlier suggestions that these parameters are positively related to the length of the preceeding repose period. The chemical difference between the eruptive material of Hekla itself and the lavas erupted in its vicinity can be explained in terms of a density-stratified magma reservoir located at the bottom of the crust. We propose that the shape of this reservoir, its location at the west margin of a propagating rift, and its association with a crustal weakness, all contribute to the high eruption frequency of Hekla.     

The effectiveness of communicative tools in addressing barriers to municipal climate change adaptation: lessons from the Netherlands

Little research has been done on the effectiveness of communicative tools for climate change adaptation. Filling this knowledge gap is relevant, as many national governments rely on communicative tools to raise the awareness and understanding of climate impacts, and to stimulate adaptation action by local governments. To address this knowledge gap, this study focuses on the effectiveness of communicative tools in addressing key municipal barriers to climate change adaptation, by conducting a large N-size empirical study in the Netherlands. This study explores the effectiveness of these tools in theory, by checking whether their goals match the perceived barriers to municipal climate change adaptation, and the effectiveness in practice by analysing whether they are used and perceived as useful. Document analyses have clarified the assumptions underlying the tools. By conducting semi-structured interviews with 84 municipalities the key barriers to climate change adaptation and the use and usefulness of the tools in practice were analysed. The research revealed that the key barriers experienced by municipalities are a lack of urgency, a lack of knowledge of risks and measures, and limited capacity, the first being the primary one. Communicative tools, while being effective in theory, are not sufficiently effective in practice in addressing the key barriers. Municipalities that are not experiencing a sense of urgency to take on adaptation planning are not likely to be activated by the tools. Advanced municipalities need more sophisticated tools. This article concludes with some suggestions to improve the effectiveness of communicative tools.

Key policy insights

• Although effective in theory in addressing key barriers to municipal adaptation planning, the effectiveness in practice of communicative tools is limited.

• To increase their effectiveness in practice, municipalities’ awareness of the existence of the communicative tools needs to be raised.

• Advanced municipalities need more sophisticated tools that are context-specific and address a wide range of climate risks.

• The effectiveness of communicative tools can be improved by embedding them in a wider mix of policy instruments.

     

Fate of Point‐Source Pesticide Spill in Clayey Till after 15 Years

This study investigated the development of pesticide pollution two, three, and 17 years after spills of the herbicides dichlorprop, mecoprop (MCPP), MCPA, 2,4‐D (phenoxy acids), simazine, and terbutylazine (triazines) in a former orchard machinery service yard. The spills had occurred over several decades on a 23‐m thick, mainly anaerobic fractured clayey till aquitard. Angled monitoring wells were installed in the aquitard 3 years after the spills ceased in 1989. In 1993, monitoring revealed that high groundwater concentrations of dichlorprop (677 µg/L) and MCPP (139 µg/L) were accumulated as a zone of maximum pollution in anaerobic and largely immobile pore water at 5 to 6 m depth in the aquitard profile. In contrast, 2,4‐D was determined in only one water sample, and MCPA and simazine and terbutylazine were determined only in low concentrations (below10 µg/L), although these pesticides had been handled at the site in greater amounts than dichlorprop and MCPP according to detailed historic information obtained for the site. Repeated monitoring in the same wells after a further 14 years in 2007 revealed that no identifiable degradation of MCPP had occurred, while dichlorprop had degraded by 75% to 80% (estimated half‐life of approximately 5 years). Furthermore, degradation products related to the phenoxy acids had accumulated, especially 4‐CPP with a maximum concentration of 218 µg/L. In the same zone, MCPA and simazine had almost disappeared. As the pollution was mainly accumulated in largely immobile pore water of the aquitard clayey matrix, and the groundwater recharge was low (30 to 60 mm/year), only minor vertical displacement of the zone with maximum pollution zone had occurred during the 15 years of monitoring. However, concentrations of dichlorprop (0.01 to 0.02 µg/L), MCPP (0.1 to 0.2 µg/L), and 4‐CPP (0.6 to 0.7 µg/L) had spread along textural heterogeneities in the aquitard into the underlying sandy aquifer at 23‐m depth.     

Cosmic ray propagation in a closed galaxy

A simple model of cosmic ray propagation is proposed from which the major experimental results can be derived: The model reproduces the observed nuclear abundances and accounts for the observed changes of nuclear composition with energy, the high degree of isotropy of cosmic ray flux at all energies, and the high degree of its constancy throughout the history of the Solar System. It is consistent with the observed size distribution of extensive airshowers, the intensity and energy distribution of the electron component, and the diffuse emission of γ-rays and radio waves. The model is characterized by the two basic assumptions: (1) that cosmic rays have been injected at an unchanging rate by sources located in the galactic spiral arms and (2) that a large-scale magnetic field retains all particles in our galaxy, where they interact with interstellar gas, so that all complex nuclei are finally fragmented and their energy dissipated in meson production and electro-magnetic interactions.