240 research outputs found
Nitrogen Emission and Deposition: The European Perspective
Europe has been successful in reducing the emissions of several nitrogenous pollutants over recent decades. This is reflected in concentrations and deposition rates that have decreased for several components. Emissions of nitrogen containing gases are estimated to have decreased in Europe by 10%, 21%, and 14% for NO, NOx, and NH3, respectively, between 1990 and 1998. The main reductions are the result of a decrease in industrial and agricultural activities in the east of Europe as a result of the economic situation, measures in the transport sector, industry and agricultural sector, with only a small part of the reduction due to specific measures designed to reduce emissions. The reduction is significant, but far from the end goal for large areas in Europe in relation to different environmental problems. The Gothenburg Protocol will lead to reductions of 50 and 12% in 2010 relative to 1990 for NOx and NH3, respectively. The N2O emissions are expected to grow between 1998 and 2010 by 9%. Further reductions are necessary to reach critical limits for ecosystem protection, air quality standards and climate change. Emissions of nitrogen compounds result from an overload of reactive nitrogen, which is produced by combustion processes, by synthesis of ammonia or by import from other areas as concentrated animal feeds. Although some improvements can be made by improving the efficiency of combustion processes and agricultural systems, measures to reduce emissions substantially need to be focused on decreasing the production or import of reactive N. Reactive N ceilings for regions based on critical limits for all N-related effects can help to focus such measures. An integrated approach might have advantages over the pollutant specific approach to combat nitrogen pollution. This could provide the future direction for European policy to reduce the impacts of excess nitrogen
European Nitrogen Assessment - Technical Summary
A century ago, when the world depended on fossil nitrogen and manure recycling, there wasinsuffi cient reactive nitrogen to feed the growing human population. With the invention of theHaber–Bosch process, humans found a way to make cheap reactive nitrogen from the almostinexhaustable supply of atmospheric di-nitrogen. What humans did not anticipate was that themassive increase in reactive nitrogen supply, exacerbated by fossil fuel burning, would lead toa web of new environmental problems cutting across all global-change challenges.Th e European Nitrogen Assessment presents the fi rst full, continental-scale assessmentof reactive nitrogen in the environment and sets the problem in context by providing amultidisciplinary introduction to the key processes in the nitrogen cycle. Issues of up-scalingfrom fi eld, farm and city to national and continental scales are addressed in detail withemphasis on opportunities for better management at local to global levels. A comprehensiveseries of maps showing nitrogen pools and fl uxes across Europe also highlight the locationof the major threats and allow a comparison of national budgets for the fi rst time. Five keysocietal threats posed by reactive nitrogen are assessed, providing a framework for a set ofpolicies that can be used for joined-up management of the nitrogen cycle in Europe. Th isincludes the fi rst cost–benefi t analysis for diff erent reactive nitrogen forms and considerationof future scenarios.JRC.DDG.H.2-Climate change and air qualit
Acid rain and air pollution : 50 years of progress in environmental science and policy
Because of its serious large-scale effects on ecosystems and its transboundary nature, acid rain received for a few decades at the end of the last century wide scientific and public interest, leading to coordinated policy actions in Europe and North America. Through these actions, in particular those under the UNECE Convention on Long-range Transboundary Air Pollution, air emissions were substantially reduced, and ecosystem impacts decreased. Widespread scientific research, long-term monitoring, and integrated assessment modelling formed the basis for the policy agreements. In this paper, which is based on an international symposium organised to commemorate 50 years of successful integration of air pollution research and policy, we briefly describe the scientific findings that provided the foundation for the policy development. We also discuss important characteristics of the science–policy interactions, such as the critical loads concept and the large-scale ecosystem field studies. Finally, acid rain and air pollution are set in the context of future societal developments and needs, e.g. the UN’s Sustainable Development Goals. We also highlight the need to maintain and develop supporting scientific infrastructures
Influence of bio-oil phospholipid on the hydrodeoxygenation activity of NiMoS/Al2O3 catalyst
Hydrodeoxygenation (HDO) activity of a typical hydrotreating catalyst, sulfided NiMo/γ-Al2O3for deoxygenation of a fatty acid has been explored in a batch reactor at 54 bar and 320\ub0C in the presence of contaminants, like phospholipids, which are known to be present in renewable feeds. Oleic acid was used for the investigation. Freshly sulfided catalyst showed a high degree of deoxygenation activity; products were predominantly composed of alkanes (C17 and C18). Experiments with a major phospholipid showed that activity for C17 was greatly reduced while activity to C18 was not altered significantly in the studied conditions. Characterization of the spent catalyst revealed the formation of aluminum phosphate (AlPO4), which affects the active phase dispersion, blocks the active sites, and causes pore blockage. In addition, choline, formed from the decomposition of phospholipid, partially contributes to the observed deactivation. Furthermore, a direct correlation was observed in the accumulation of coke on the catalyst and the amount of phospholipid introduced in the feed. We therefore propose that the reason for the increased deactivation is due to the dual effects of an irreversible change in phase to aluminum phosphate and the formation of choline
A chronology of global air quality
Air pollution has been recognized as a threat to human health since the time of Hippocrates, ca 400 BC. Successive written accounts of air pollution occur in different countries through the following two millennia until measurements, from the eighteenth century onwards, show the growing scale of poor air quality in urban centres and close to industry, and the chemical characteristics of the gases and particulate matter. The industrial revolution accelerated both the magnitude of emissions of the primary pollutants and the geographical spread of contributing countries as highly polluted cities became the defining issue, culminating with the great smog of London in 1952. Europe and North America dominated emissions and suffered the majority of adverse effects until the latter decades of the twentieth century, by which time the transboundary issues of acid rain, forest decline and ground-level ozone became the main environmental and political air quality issues. As controls on emissions of sulfur and nitrogen oxides (SO2 and NOx) began to take effect in Europe and North America, emissions in East and South Asia grew strongly and dominated global emissions by the early years of the twenty-first century. The effects of air quality on human health had also returned to the top of the priorities by 2000 as new epidemiological evidence emerged. By this time, extensive networks of surface measurements and satellite remote sensing provided global measurements of both primary and secondary pollutants. Global emissions of SO2 and NOx peaked, respectively, in ca 1990 and 2018 and have since declined to 2020 as a result of widespread emission controls. By contrast, with a lack of actions to abate ammonia, global emissions have continued to grow
The Global Atmospheric Pollution Forum (GAPF) emission inventory preparation tool and its application to Côte d’Ivoire
Low- and middle-income countries (LMICs) often lack the necessary tools, guidance, and capacity for compiling an emission inventory (EI) for air pollutants. A reliable EI is an important prerequisite for the identification of key emissions sources, as an input to modelling atmospheric transport and impacts of air pollutants, and the identification of appropriate mitigation policies. The publicly-available Global Atmospheric Pollution Forum Emission Inventory (GAPF-EI) tool meets the need of LMICs for a user-friendly tool allowing in-country practitioners to compile their own EIs. The species covered are SO2, NOX, CO, NMVOC, CH4, NH3, PM10, PM 2.5, black carbon, organic carbon and CO2. Output from the tool can therefore support the development of integrated air quality and climate change mitigation strategies. This tool incorporates default emission factors and inventory methods conforming with internationally recognised approaches. The GAPF-EI tool enables emissions to be estimated for technologies or practices that are often of little or no relevance to developed countries, but may represent key sources in LMICs. This paper describes the GAPF-EI tool and its application to Côte d’Ivoire where emissions from traditional biomass cookstoves, vegetation fires, traditional charcoal manufacture, road transport (including dust from unpaved roads) and open burning of municipal solid waste were found to be particularly important components of the inventory. The application of the GAPF-EI approach to Côte d’Ivoire has demonstrated its utility in addressing sources of particular relevance to LMICs in addition to providing a user-friendly, transparent and flexible EI preparation tool
Scaling ozone responses of forest trees to the ecosystem level in a changing climate
Many uncertainties remain regarding how climate change will alter the structure and function of forest ecosystems. At the Aspen FACE experiment in northern Wisconsin, we are attempting to understand how an aspen/birch/maple forest ecosystem responds to long-term exposure to elevated carbon dioxide (CO 2 ) and ozone (O 3 ), alone and in combination, from establishment onward. We examine how O 3 affects the flow of carbon through the ecosystem from the leaf level through to the roots and into the soil micro-organisms in present and future atmospheric CO 2 conditions. We provide evidence of adverse effects of O 3 , with or without co-occurring elevated CO 2 , that cascade through the entire ecosystem impacting complex trophic interactions and food webs on all three species in the study: trembling aspen ( Populus tremuloides Michx . ), paper birch ( Betula papyrifera Marsh), and sugar maple ( Acer saccharum Marsh). Interestingly, the negative effect of O 3 on the growth of sugar maple did not become evident until 3 years into the study. The negative effect of O 3 effect was most noticeable on paper birch trees growing under elevated CO 2 . Our results demonstrate the importance of long-term studies to detect subtle effects of atmospheric change and of the need for studies of interacting stresses whose responses could not be predicted by studies of single factors. In biologically complex forest ecosystems, effects at one scale can be very different from those at another scale. For scaling purposes, then, linking process with canopy level models is essential if O 3 impacts are to be accurately predicted. Finally, we describe how outputs from our long-term multispecies Aspen FACE experiment are being used to develop simple, coupled models to estimate productivity gain/loss from changing O 3 .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72464/1/j.1365-3040.2005.01362.x.pd
Managing the European Nitrogen Problem. A proposed strategy for integration of European Research on the multiple effects of reactive nitrogen
Date de publication : 2009/07absen
NITREX: responses of coniferous forest ecosystems to experimentally changed deposition of nitrogen
- …