352 research outputs found

    Cambiamenti climatici e sicurezza alimentare

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    This paper presents an overview of the recent scientific literature on the link between food production and climate change, both for present and future impacts of climate changes, and for the contribution that policies and measures in the sector of food production and consumption can give to reduce greenhouse gas emissions. Many available studies show that agriculture and food production are inherently sensitive to climate variability and change, as a result of either natural causes or human activities, and outline the likely direct influences of climate change on crops production system for food and fodder, as well as other indirect impacts on the health of livestock, and on trade of food and food products. Conclusions common to the different studies are: a) the improvement of model projections of the effects of climate change at regional and local level is crucial to better define the impacts and steer the decision-making process of adaptation of food systems; b) the impacts of climate change on food security will be greater in countries which already suffer from high levels of hunger and are vulnerable to the effects of extreme weather events, are potentially large and will grow in the future if adaptive responses will not be implemented; d) although the climate crisis is mainly related to energy production, food production will play an important role both for the contribution to the reduction of greenhouse gas emissions from agricultural and livestock activities and for the control of deforestation

    Full Sky Study of Diffuse Galactic Emission at Decimeter Wavelengths

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    A detailed knowledge of the Galactic radio continuum is of high interest for studies of the dynamics and structure of the Galaxy as well as for the problem of foreground removal in Cosmic Microwave Background measurements. In this work we present a full-sky study of the diffuse Galactic emission at frequencies of few GHz, where synchrotron radiation is by far the dominant component. We perform a detailed combined analysis of the extended surveys at 408, 1420 and 2326 MHz (by Haslam et al. 1982, Reich 1982, Reich & Reich, 1986 and Jonas et al. 1998, respectively). Using the technique applied by Schlegel et al. (1998) to the IRAS data, we produce destriped versions of the three maps. This allows us to construct a nearly-full-sky map of the spectral index and of the normalization factor with sub-degree angular resolution. The resulting distribution of the spectral indices has an average of beta = 2.695 and dispersion sigma_{beta} = 0.120. This is representative for the Galactic diffuse synchrotron emission, with only minor effects from free-free emission and point sources.Comment: 10 pages, 16 jpeg figures, accepted to Astronomy & Astrophysics, Comments and figure adde

    Impact of the dropping activity with vehicle age on air pollutant emissions

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    Road transport is a major source of air pollution especially in cities. Detailed calculations are needed to support road transport emission inventories due to the variance of technologies and operating conditions encountered on the roads. The annual distance driven by cars in relation to their characteristics is an important variable in such calculations. In this work, a large amount of mileage data were collected from second–hand car sellers in Italy and were then analyzed in order to understand the influence of vehicle age on annual mileage driven. The available data enabled the development of dropping functions of annual mileage with vehicle age. It was found that the average mileage of 10 year old cars is only approximately 40% of the mileage driven on year one. This drops to approximately only 10% for 20–year old cars. The findings are of paramount importance in environmental calculations as road transport NOX and PM emissions drop by more than 20% when the corrected functions are used compared to using a constant mileage. Not introducing such a correction may result to an approximately 8% higher nation–wide NOX emissions with negative implications towards meeting the national emission ceilings. In terms of policy implications, the dropping activity with age results to a decrease in the importance of accelerated scrappage schemes and of environmental zones in air quality

    Influence of climate change on the frequency of daytime temperature inversions and stagnation events in the Po Valley: historical trend and future projections

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    This work analyzes the frequency of days characterized by daytime temperature inversion and air stagnation events in the Po valley area. The analysis is focused on both historical series and future projections under climate change. Historical sounding data from two different Italian stations are used as well as future projections data, provided by CMCC-CCLM 4-8-19 regional climate model (MED-CORDEX initiative). A new method to detect layers of temperature inversion is also presented. The developed method computes the occurrence of a temperature inversion layer for a given day at 12 UTC without a detailed knowledge of temperature vertical profile. This method was validated using sounding data and applied to the model projections, under two different emissions scenarios (RCP4.5 and RCP8.5). Under RCP4.5 intermediate emissions scenario, the occurrence of temperature inversions is projected to increase by 12 days/year (around + 10%) in the last decade of 21st century compared to 1986–2005 average. However, the increase in temperature inversions seems to be especially concentrated in the warm period. Under RCP8.5 extreme scenario, temperature inversions are still projected to increase, though to a lesser extent compared to RCP4.5 scenario (+ 6 days/year in the last decade of 21st century). A similar trend was found also for air stagnation events, which take into account the variation of precipitation pattern and wind strength. The expected increases are equal to + 13 days/year and + 11 days/year in the last decade of 21st century compared to 1986–2005 average, under RCP4.5 and RCP8.5 scenarios respectively

    Importance of activity data for improving the residential wood combustion emission inventory at regional level

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    The contribution of residential wood combustion (RWC) to emission inventory at local level was estimated using a bottomeup approach for the Lombardy Region of North Italy. A survey, based on the CATI (Computer Assisted Telephone Interviewing) method, has been undertaken through 18,000 interviews. The interviews had the objective to characterize the RWC use in this region, in term of both total and municipal wood consumption. Details on the type of appliances used in RWC were also gathered. The results of the survey were then statistically analyzed in order to allow an estimate of RWC with high spatial resolution (i.e., at municipal level) in relation to the size and altitude of the territory. The work provides new evidence of the importance of wood combustion as a key source for PM and NMVOC emissions at local level, and thus highlights the importance of technological improvements and new policies aimed at emission reduction in this sector. Considering the great differences in average PM emission factors between low efficiency appliances (fireplaces, old stoves) and high efficiency ones (new stoves, pellet burners), this work emphasizes the importance of obtaining more detailed information on the types of wood appliances used for arriving at a reliable PM emission inventory for RWC

    Fattori di emissione dalla combustione di legna e pellet in piccoli apparecchi domestici

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    The aim of this study was to report emission factors of pollutants (i.e., carbon monoxide, nitrogen oxides, non-methane hydrocarbons, particulate matter, polycyclic aromatic hydrocarbons, dioxins) from biomass burning residential heating appliances. The influence of several factors such as biomass type, appliance and combustion cycle was investigated. Four manually fed (6-11 kW) firewood burning and two automatic wood pellets (8.8-25 kW) appliances were tested under real-world operating conditions in order to determine the actual environmental performance of the appliance. The experimental EFs were also compared with the values proposed by the European emission inventory guidebook used in the local inventory in order to evaluate their representativeness of real world emissions. The composite macropollutant EFs for manually fed appliances are: for CO 5858 g GJ-1, for NOx 122 g GJ-1, NMHC 542 g GJ-1, PM 254 g GJ-1, whereas emissions are much lower for automatic pellets appliances: CO 219 g GJ-1, for NOx 66 g GJ-1, NMHC 5 g GJ-1, PM 85 g GJ-1. The open fireplace appears to have very high emission factors, however traditional and advanced stoves show the highest overall CO EFs. Especially for the advanced stove real-world emissions are far worse than those measured under cycles used for type testing of residential solid fuel appliances. No great difference is observed for different firewood types in batch working appliances, diversely the quality of the pellets is observed to influence directly the emission performance of the automatic appliances. Benzo(b)fluoranthene is the PAH with the highest contribution (110 mg GJ-1 for manual appliances and 2 mg GJ-1 for automatic devices) followed by benzo(a)pyrene (77 mg GJ-1 for manual appliances and 0,8 mg GJ-1 for automatic devices)

    Le emissioni in atmosfera dalle combustioni in Lombardia

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    Il lavoro presenta le stime delle emissioni in atmosfera di polveri fini, precursori di polveri fini e gas serra in Lombardia provenienti dalle attività di combustione di combustibili e carburanti, come stimate dall’inventario regionale INEMAR per l’anno 2003. I dati dei consumi elaborati nell’inventario derivano da informazioni raccolte sia mediante questionari relativi alle principali sorgenti puntuali della regione, sia consultando le diverse fonti statistiche. Le emissioni in atmosfera sono stimate sia attraverso dati derivanti da misure effettuate presso gli impianti che tramite fattori di emissione proposti in letteratura e utilizzati in ambito EMEP-Corinair e IPCC (Intergovernmental Panel on Climate Change). La combustione nel settore del trasporto stradale risulta essere la principale sorgente per numerosi inquinanti, fra cui PM10, NOx, SO2 e CO. L’olio combustibile utilizzato per la produzione di energia è la maggiore fonte di SO2 (56% delle emissioni totali regionali), mentre il gasolio per autotrazione fornisce il principale contributo alle emissioni di NOx (44% del totale). Per le emissioni di polveri (sia PM10 che PM2,5), oltre ai determinanti contributi della combustione del gasolio per autotrazione e della legna in ambito domestico, sono rilevanti anche i processi di usura nel traffico stradale (pneumatici, freni, abrasione dell’asfalto) e le attività relative al settore agro-zootecnico. La benzina è la principale fonte di CO (50%), mentre il metano costituisce una sorgente di grande importanza (45%) per la CO2 e di interesse anche per gli ossidi di azoto (21% del totale regionale). Il lavoro fornisce altresì una valutazione dei fattori di emissione medi dalle attività di combustione in Lombardia a diverse scale di dettaglio

    What people know about congenital CMV: an analysis of a large heterogeneous population through a web-based survey

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    BACKGROUND: Congenital CMV (cCMV) infection is a serious public health issue due to both its worldwide prevalence and the severe and permanent impairments it causes. However, awareness of this infection is low in the general population and among pregnant women, and it also seems to be generally disregarded by healthcare providers. The identification of factors behind this inadequate level of knowledge could provide a basis for future preventive measures. This study aimed at evaluating awareness of CMV and cCMV infection and its correlation with socio-demographic variables in a general population. METHODS: The survey was carried out by computer-assisted web interviewing (CAWI). A questionnaire was sent via e-mail to the 70,975 individuals who comprised the whole population (students, administrative staff, teaching staff) of Milan University, Italy in 2015. RESULTS: Out of the 10,190 respondents, 5,351 (52.5 %) had already heard of CMV but only 3,216 (31.8 %) knew that this virus could be implicated in congenital infection. Urine and breastfeeding were the least recognized transmission routes for CMV infection; less than half of respondents accurately identified the right symptoms and sequelae caused by cCMV infection. The correct hygienic measures against cCMV infection were identified in percentages ranging from 55.6 to 75 % depending on the measures proposed but about one in three of interviewees deemed those measures unnecessary in the event of a pregnant woman already being CMV seropositive. From the mean knowledge scores the most complete quality of awareness of CMV turned out to be linked to childbearing-age (25–40 year) and with not having children, even if results for non-parents showed less of them having heard of cCMV than parents. CONCLUSION: Our results indicate a limited and confused awareness of cCMV infection in a large, fairly young and well-educated Italian population
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