Cambiamenti climatici e sicurezza alimentare

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

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

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

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)

10 ANNI DI CAMBIAMENTI CLIMATICI: IL PESO DEI RITARDI E I PRIMI TIMIDI SEGNALI DI AZIONE

Se negli ultimi 10 anni gli effetti del riscaldamento globale sono diventati sempre più evidenti, come del resto previsto dalla comunità scientifica, è cresciuta anche la risposta globale alla crisi climatica, seppure in modo del tutto insufficiente rispetto a quanto necessario per stabilizzare l’aumento delle temperature globali. I continui record delle temperature globali, uniti ad un aumento degli impatti delle ondate di calore e degli estremi di precipitazione, sempre più percepibili, mostrano l’urgenza di un’azione maggiormente incisiva contro il cambiamento climatico. L’articolo passa in rassegna l’andamento dei principali fattori climalteranti, di alcuni indicatori del riscaldamento globale, nonché delle principali tendenze nelle azioni di contrasto alla crisi climatica.If in the last 10 years the effects of global warming are increasingly evident, as predicted by the scientific community, the global response to the climate crisis has grown, albeit in a completely insufficient way compared to what is necessary to stabilise the increase in global temperatures. Continued global temperature records, coupled with an increasing impact of heat waves and precipitation extremes, show the urgency of the need for action against climate change. The article reviews the trend of the main climate-changing factors, some indicators of global warming, as well as the main trends in actions to combat the climate crisis

Techno-economic evaluation of buffered accelerated weathering of limestone as a CO2 capture and storage option

Carbon dioxide storage technologies are needed not only to store the carbon captured in the emissions of hard-to-abate sectors but also for some carbon dioxide removal technologies requiring a final and permanent storage of CO2. The pace and scale of geological CO2 storage deployment have fallen short of expectations, and there is a growing interest in ocean-based CO2 storage options. As complementary to geological storage, buffered accelerated weathering of limestone (BAWL) has been proposed to produce a buffered ionic solution at seawater pH, derived from the reaction in seawater between a CO2 stream and a micron-sized powder of calcium carbonate (CaCO3), within a long tubular reactor. The addition of calcium hydroxide to buffer the unreacted CO2 before the discharge in seawater is also envisaged. BAWL avoids the risks of CO2 degassing back into the atmosphere and does not induce seawater acidification. This work presents a mass and energy balance and preliminary cost analysis of the technology for different configurations of discharge depth (100, 500, 3,000 m), pipeline length (10, 25, 100 km) and diameter of CaCO3 particles (1, 2, 10 mu m) fed in the tubular reactor. The total energy consumption to capture and store 1 t of CO2 generated by a steam-methane reforming (SMR) process ranges from 1.3 to 2.2 MWh. The CO2 released from the CaCO3 calcination to produce the buffering solution leads to a total CO2 storage requirement 43-85% higher than the CO2 derived by SMR. The total cost to capture and store 1 t of CO2 from SMR is estimated in the range 142-189 euro

Ocean liming effects on dissolved organic matter dynamics

Ocean liming has gained attention as a potential solution to mitigate climate change by actively removing carbon dioxide (CO2) from the atmosphere. The addition of hydrated lime to oceanic surface water leads to an increase in alkalinity, which in turn promotes the uptake and sequestration of atmospheric CO2.Despite the potential of this technique, its effects on the marine ecosystem are still far from understood, and there is currently no information on the potential impacts on the concentration and quality of dissolved organic matter (DOM), which is one of the largest, most complex and yet least understood mixtures of organic molecules on Earth.The aim of this study is to provide the first experimental evidence about the potential effects of hydrated lime addition on DOM dynamics in the oceans by assessing changes in its concentration and optical properties (absorption and fluorescence).To investigate the effects of liming on DOM pools with different concentrations and quality, seawater was collected from two contrasting environments: the oligotrophic Mediterranean Sea, known for its dissolved organic carbon (DOC) concentration comparable to that observed in the oceans, and the eutrophic Baltic Sea, characterized by high DOM concentration mostly of terrestrial origin. Hydrated lime was added to both waters to reach pH values of 9 and 10.Our findings reveal that the addition of hydrated lime has a noticeable effect on DOM dynamics in both the Mediterranean Sea and Baltic Sea, determining a reduction in DOC concentration and a change in the optical properties (absorption and fluorescence) of DOM. These effects, detectable at pH 9, become significant at pH 10 and are more pronounced in the Mediterranean Sea than in the Baltic Sea. These potential short-term effects should be considered within the context of the physicochemical properties of seawater and the seasonal variability

Global climate change

Global climate change is happening and an overwhelming majority of the scientific community consider the risk of climate change real and severe. The knowledge summary in Fifth Assessment Report (AR5) of the Intergovernmental Panel on climate change (IPCC, 2014a), 1 provided new evidence of the reality of climate change, on the basis of many independent analyses from observations of the climate system, paleoclimate archives, theoretical studies of climate processes and simulations using climate models

La contabilità ambientale per la stima delle emissioni e delle compensazioni di gas climalteranti

La stima delle emissioni di gas climalteranti (principalmente CO2) è sempre più utilizzata come elemento di valutazione delle politiche ambientali, in particolare con la realizzazione di inventari delle emissioni a diverse scale territoriali e per valutare interventi di riduzione o progetti di compensazione delle emissioni. A questo fine sono spesso da superare criticità legate alla carenza di dati e sono da considerare adeguatamente le assunzioni metodologiche che possono influire notevolmente sui risultati