A simplified approach to the indirect evaluation of the chemical composition of atmospheric aerosols from PM mass concentrations

The present work shows a straightforward procedure to indirectly estimate the chemical composition at a given site only from the determination of the PM concentrations, and the classification of the days according to the main meteorological scenarios. A previous study based on the mean chemical composition associated to the main meteorological scenarios is required.This experiment has been carried out with data from two monitoring sites in the North-Western Mediterranean, one regional and one suburban background. At both sites, one-year datasets on chemical PM₁₀ composition were obtained. Based on these datasets, the mean PM₁₀ compositions according to the most relevant meteorological situations were calculated for both locations. After that, the reconstruction of the chemical composition for all the days with available PM₁₀ concentrations was completed. Subsequently, the estimated PM₁₀ composition was compared with that determined experimentally. The comparison between the rebuilt and the experimental results was very satisfactory in the case of the regional background site, and relatively replaced in the other case. Furthermore, the validation of the method at the regional background site has been conducted from the reconstruction of a 4-year data base, and subsequent comparison with the experimental chemical composition.Our results show that it is possible to attain a good approach to the chemical composition at regional background sites, where local emission sources are negligible. Conversely, when the local sources rise in importance, i.e., at a suburban background site, the approach is suitable only for those components with a more regional origin and/or those from long range transport of air masses.     

An urban emissions inventory for South America and its application in numerical modeling of atmospheric chemical composition at local and regional scales

This work describes the development of an urban vehicle emissions inventory for South America, based on the analysis and aggregation of available inventories for major cities, with emphasis on its application in regional atmospheric chemistry modeling. Due to the limited number of available local inventories, urban emissions were extrapolated based on the correlation between city vehicle density and mobile source emissions of carbon monoxide (CO) and nitrogen oxides (NOx). Emissions were geographically distributed using a methodology that delimits urban areas using high spatial resolution remote sensing products. This numerical algorithm enabled a more precise representation of urban centers. The derived regional inventory was evaluated by analyzing the performance of a chemical weather forecast model in relation to observations of CO, NOx and O₃ in two different urban areas, São Paulo and Belo Horizonte. The gas mixing ratios simulated using the proposed regional inventory show good agreement with observations, consistently representing their hourly and daily variability. These results show that the integration of municipal inventories in a regional emissions map and their precise distribution in fine scale resolutions are important tools in regional atmospheric chemistry modeling.     

Overview of strontium-89,90 deposition measurements in Finland 1963-2005

In Finland the deposition of strontium-89 (⁹⁰Sr) and strontium-90 (⁹⁰Sr) has been monitored since the early 1960s. The measured cumulative ⁹⁰Sr deposition in 1963-2005 is on average 1200 Bq m⁻², of which 150 Bq m⁻² originates from the Chernobyl accident. Adding to this the deposition in 1945-1962 produces a value of 2040 Bq m⁻² for the cumulative deposition in Finland. The nuclear explosion-derived deposition up to 1985 obtained in this study, 1850 Bq m⁻², is in good agreement with the zonal ⁹⁰Sr deposition of 1740 Bq m⁻² in the 60°N-70°N latitude band estimated by UNSCEAR. The regional deposition patterns of ⁸⁹Sr and ⁹⁰Sr following the Chernobyl accident resemble those of the refractory nuclides such as ^239,240Pu and ⁹⁵Zr. The total deposition of Chernobyl-derived ⁹⁰Sr in Finland was about 5.3 × 10¹³ Bq. This activity corresponds to 0.027% of the reactor core inventory and 0.66% of the atmospheric emissions from the accident. The corresponding figures for ⁸⁹Sr are 4.5 × 10¹⁴ Bq, 0.023% and 0.56%, respectively.     

The distribution of Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

We record the distribution of ¹³⁷Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as ¹³⁷Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris¹³⁷Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher ¹³⁷Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of ¹³⁷Cs within the plants. The patterns of ¹³⁷Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The ¹³⁷Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between ¹³⁷Cs and Rb (r = 0.89), and between ¹³⁷Cs and stable Cs (r = 0.84). This suggests similarities between ¹³⁷Cs and Rb in uptake and relocation within the Sphagnum, but that ¹³⁷Cs differs from K.     

Does intensity of change matter? Factors affecting adoption of agri-environmental schemes in Spain

Agri-environmental schemes (AES) are the main policy instrument currently available in the EU to promote environmentally-friendly farming practices. However, the rate of adoption of these measures is still relatively low in southern Europe, and understanding how these rates can be increased is still an open issue. The goal of this paper is to increase that understanding by testing whether the factors which determine AES sign-up decisions are influenced by the intensity of change in farming practices that are brought about by adopting the scheme. A micro-economic model reflecting farmer AES sign-up decisions is proposed and applied to two schemes in Spain respectively requiring major or minor intensity of change in practices by surveying farmers eligible for both schemes. The results show that farm structural factors play a role when major practice change is required by the scheme, yet when dealing with minor change, individual farmer characteristics play a more determining role. Social capital and farmer attitude are important factors in both the AES surveyed. Therefore, it may be concluded that improving agronomic design would be an important tool to improve farmer participation in AES where major change is involved, whereas improved targeting and extension would help uptake for AES involving a lesser degree of change.     

Climate Change and Mitigation

Planet Earth has experienced repeated changes of its climate throughout time. Periods warmer than today as well as much colder, during glacial episodes, have alternated. In our time, rapid population growth with increased demand for natural resources and energy, has made society increasingly vulnerable to environmental changes, both natural and those caused by man; human activity is clearly affecting the radiation balance of the Earth. In the session “Climate Change and Mitigation” the speakers offered four different views on coal and CO₂: the basis for life, but also a major hazard with impact on Earth’s climate. A common denominator in the presentations was that more than ever science and technology is required. We need not only understand the mechanisms for climate change and climate variability, we also need to identify means to remedy the anthropogenic influence on Earth’s climate.     

Closing a Loop: Substance Flow Analysis of Nitrogen and Phosphorus in the Rainbow Trout Production and Domestic Consumption System in Finland

Ongoing eutrophication is changing the Baltic Sea ecosystem. Aquaculture causes relatively small-scale nutrient emissions, but local environmental impact may be considerable. We used substance flow analysis (SFA) to identify and quantify the most significant flows and stocks of nitrogen (N) and phosphorus (P) related to rainbow trout aquaculture in Finland. In 2004–2007, the input of nutrients to the system in the form of fish feed was 829 t N year⁻¹ and 115 t P year⁻¹. Around one-fifth of these nutrients ended up as food for human consumption. Of the primary input, 70% ended up in the Baltic Sea, directly from aquaculture and indirectly through waste management. The nutrient cycle could be closed partially by using local fish instead of imported fish in rainbow trout feed, thus reducing the net load of N and P to a fraction.     

The Fallacies of Concurrent Climate Policy Efforts

Climate policy has assumed an extreme degree of urgency in the international debate in recent years. This article begins by taking a critical look at the scientific underpinnings of the efforts to stabilize the climate. It points to several serious question marks on the purported relationship between greenhouse gas emissions and global warming, and expresses distrust about claims of impending catastrophes related to rising sea levels, hurricanes, and spread of infectious disease. It then reviews the concurrent climate policy efforts and concludes that they are incoherent, misguided and unduly costly, and that they have so far had no perceptible impact on anthropogenic greenhouse gas emissions. The exceedingly ambitious policy plans currently under preparation suffer from similar fallacies. For these reasons, but also because of the remaining scientific doubts and the exorbitant costs that have to be incurred, skepticism is expressed about the preparedness to implement the climate policy plans currently on the table.