scholarly journals Climate change as a confounding factor in reversibility of acidification: RAIN and CLIMEX projects

2001 ◽  
Vol 5 (3) ◽  
pp. 477-486 ◽  
Author(s):  
R. F. Wright ◽  
A. Jenkins

Abstract. The RAIN and CLIMEX experiments at Risdalsheia, southernmost Norway, together cover 17 years (1984-2000) of whole-catchment manipulation of acid deposition and climate. A 1200 m2 roof placed over the forest canopy at KIM catchment excluded about 80% of ambient acid deposition; clean rain was sprinkled under the roof. A climate change treatment (3.7°C increase in air temperature and increase in air carbon dioxide concentrations to 560 ppmv) was superimposed on the clean rain treatment for four years (1995-1998). Sea-salt inputs and temperature are climate-related factors that influence water chemistry and can confound long-term trends caused by changes in deposition of sulphur and nitrogen. The RAIN and CLIMEX experiments at Risdalsheia provided direct experimental data that allow quantitative assessment of these factors. Run-off chemistry responded rapidly to the decreased acid deposition. Sulphate concentrations decreased by 50% within three years; nitrate and ammonium concentrations decreased to new steady-state levels within the first year. Acid neutralising capacity increased and hydrogen ion and inorganic aluminium decreased. Similar recovery from acidification was also observed at the reference catchment, ROLF, in response to the general 50% reduction in sulphate deposition over southern Norway in the late 1980s and 1990s. Variations in sea-salt deposition caused large variations in run-off chemistry at the reference catchment ROLF and the year-to-year noise in acid neutralising capacity was as large as the overall trend over the period. These variations were absent at KIM catchment because the sea-salt inputs were held constant over the entire 17 years of the clean rain treatment. The climate change experiment at KIM catchment resulted in increased leaching of inorganic nitrogen, probably due to increased mineralisation and nitrification rates in the soils. Keywords: acid deposition, global change, water, soil, catchment, experiment, Norway.

2001 ◽  
Vol 5 (3) ◽  
pp. 339-350 ◽  
Author(s):  
F. Moldan ◽  
R. F. Wright ◽  
S. Löfgren ◽  
M. Forsius ◽  
T. Ruoho-Airola ◽  
...  

Abstract. International agreements to reduce the emissions of acidifying pollutants have resulted in major changes in deposition of sulphur and nitrogen in southern Scandinavia over the past 25 years. Long-term monitoring of deposition and run-off chemistry over the past 12-25 years at nine small calibrated catchments in Finland, Norway and Sweden provide the basis for analysis of trends with special attention to recovery in response to decreased sulphur and nitrogen deposition in the 1980s and 1990s. During the 1980s and 1990s sulphate deposition in the region decreased by 30 to 60%, whereas inorganic nitrogen deposition showed very little change until the mid-1990s. Deposition of non-marine base cations (especially calcium) declined in the 1990s most markedly in southern Finland. Run-off response to these changes in deposition has been rapid and clear at the nine catchments. Sulphate and base cations (mostly calcium) concentrations declined and acid neutralising capacity increased. Occasional years with unusually high inputs of sea-salt confound the general trends. Trends at all the catchments show the same general picture as that from small lakes in Scandinavia and in acid-sensitive waters elsewhere in Europe. Keywords: acidification, recovery, Scandinavia, catchment, trend analysis


2001 ◽  
Vol 5 (3) ◽  
pp. 421-432 ◽  
Author(s):  
R. C. Ferrier ◽  
R. C. Helliwell ◽  
B. J. Cosby ◽  
A. Jenkins ◽  
R. F. Wright

Abstract. The Galloway region of south-west Scotland has historically been subject to long-term deposition of acidic precipitation which has resulted in acidification of soils and surface waters and subsequent damage to aquatic ecology. Since the end of the 1970s, however, acidic deposition has decreased substantially. The general pattern is for a rapid decline in non-marine sulphate in rainwater over the period 1978-1988 followed by stable concentrations to the mid-1990s. Concentrations of nitrate and ammonium in deposition have remained constant between 1980 and 1998. Seven water quality surveys of 48 lochs in the Galloway region have been conducted between 1979 and 1998. During the first 10 years, from 1979, there was a major decline in regional sulphate concentrations in the lochs, which was expected to have produced a decline in base cations and an increase in the acid neutralising capacity. But sea-salt levels (as indicated by chloride concentrations) were approximately 25% higher in 1988 than in 1979 and thus short-term acidification due to sea-salts offset much of the long-term recovery trend expected in the lochs. During the next 10 years, however, the chloride concentrations returned to 1979 levels and the lochs showed large increases in acid neutralising capacity despite little change in sulphate concentrations. From the observed decline in sulphate deposition and concentrations of sulphate in the lochs, it appears that approximately 75% of the possible improvement in acid neutralising capacity has already occurred over the 20-year period (1979-1998). The role of acid deposition as a driving factor for change in water chemistry in the Galloway lochs is confounded by concurrent changes in other driving variables, most notably, factors related to episodic and year-to-year variations in climate. In addition to inputs of sea-salts, climate probably also influences other chemical signals such as peaks in regional nitrate concentrations and the sharp increase in dissolved organic carbon during the 1990s. Keywords: acidification, recovery, Galloway, sulphur, nitrogen


2001 ◽  
Vol 5 (3) ◽  
pp. 327-338 ◽  
Author(s):  
B. L. Skjelkvåle ◽  
J. Mannio ◽  
A. Wilander ◽  
T. Andersen

Abstract. Sulphate deposition has decreased by about 60% in the Nordic countries since the early 1980s. Nitrogen deposition has been roughly constant during the past 20 years, with only a minor decrease in the late 1990s. The resulting changes in the chemistry of small lakes have been followed by national monitoring programmes initiated in the 1980s in Finland (163 lakes), Norway (100 lakes) and Sweden (81 lakes). These lakes are partly a subset from the survey of 5690 lakes in the Northern European lake survey of 1995. Trend analyses on data for the period 1990-1999 show that the non-marine sulphate concentrations in lakes have decreased significantly in 69% of the monitored lakes. Changes were largest in lakes with the highest mean concentrations. Nitrate concentrations, on the other hand, were generally low and showed no systematic changes. Concentrations of non-marine base cations decreased in 26% of the lakes, most probably an ionic-strength effect due to the lower concentrations of mobile strong-acid anions. Acid neutralising capacity increased in 32% of the lakes. Trends in recovery were in part masked by large year-to-year variations in sea-salt inputs and by increases in total organic carbon concentrations. These changes were most probably the result of climatic variations. Nordic lakes, therefore, show clear signs of recovery from acidification. Recovery began in the 1980s and accelerated in the 1990s. Reductions in sulphur deposition are the major "driving force" in the process of recovery from acidification. Further recovery can be expected in the next 10 years if the Gothenburg protocol on emissions of acidifying pollutants is implemented. Keywords: Nordic countries, sulphur deposition, lakes, recovery


2007 ◽  
Vol 4 (5) ◽  
pp. 2901-2944 ◽  
Author(s):  
C. D. Evans ◽  
B. Reynolds ◽  
C. Hinton ◽  
S. Hughes ◽  
D. Norris ◽  
...  

Abstract. This study assesses the major chemical processes leading to acid extremes in a small, moorland stream in mid-Wales, UK, which has been monitored since 1979. Results suggest that base cation (mainly calcium) dilution, the "sea-salt effect", and elevated nitrate pulses, are the major causes of seasonal/episodic minima in acid neutralising capacity (ANC), and that the relative importance of these drivers has remained approximately constant during 25 years of decreasing acid deposition and associated long-term chemical recovery. Many of the chemical variations causing short-term reductions in stream acidity, particularly base cation dilution and organic acid increases, are closely related to changes in water-flowpath and therefore to stream discharge. Changes in the observed pH-discharge relationship over time indicate that high-flow pH has increased more rapidly than mean-flow pH, and therefore that episodes have decreased in magnitude since 1980. However a two-box application of the dynamic model MAGIC, whilst reproducing this trend, suggests that it will not persist in the long term, with mean ANC continuing to increase until 2100, but the ANC of the upper soil (the source of relatively acid water during high-flow episodes) stabilising close to zero beyond 2030. With climate change predicted to lead to an increase in maximum flows in the latter half of the century, high-flow related acid episodes may actually become more rather than less severe in the long term, although the model suggests that this effect may be small. Two other predicted climatic changes could also detrimentally impact on acid episodes: increased severity of winter "sea-salt" episodes due to higher wind speeds during winter storms; and larger sulphate pulses due to oxidation of reduced sulphur held in organic soils, during more extreme summer droughts. At the Gwy, the near-coastal location and relatively small extent of peat soils suggest that sea-salt episodes may have the greatest influence.


1998 ◽  
Vol 2 (4) ◽  
pp. 385-397 ◽  
Author(s):  
R. F. Wright ◽  
B. A. Emmett ◽  
A. Jenkins

Abstract. Nitrogen processes are now included in a new version of MAGIC (version 7), a process-oriented catchment-scale model for simulating runoff chemistry. Net retention of nitrogen (N) is assumed to be controlled by plant uptake and the carbon/nitrogen (C/N) ratio of soil organic matter, the latter as evidenced by empirical data from forest stands in Europe. The ability of this version of MAGIC 7 to simulate and predict inorganic N concentrations in runoff is evaluated by means of data from whole-ecosystem manipulation experiments at Aber, Wales, UK, (nitrogen addition as part of the NITREX project) and Risdalsheia, Norway (exclusion of acid deposition as part of the RAIN project and climate change as part of the CLIMEX project). MAGIC 7 simulated the changes in N leaching satisfactorily as well as changes in base cations and acid neutralising capacity observed at these two sites. MAGIC 7 offers a potential tool for regional assessments and scenario studies of the combined effects of acid deposition, land-use and climate change.


2008 ◽  
Vol 12 (2) ◽  
pp. 337-351 ◽  
Author(s):  
C. D. Evans ◽  
B. Reynolds ◽  
C. Hinton ◽  
S. Hughes ◽  
D. Norris ◽  
...  

Abstract. This study assesses the major chemical processes leading to acid extremes in a small, moorland stream in mid-Wales, UK, which has been monitored since 1979. Results suggest that base cation (mainly calcium) dilution, the "sea-salt effect", and elevated nitrate pulses, are the major causes of seasonal/episodic minima in acid neutralising capacity (ANC), and that the relative importance of these drivers has remained approximately constant during 25 years of decreasing acid deposition and associated long-term chemical recovery. Many of the chemical variations causing short-term reductions in stream acidity, particularly base cation dilution and organic acid increases, are closely related to changes in water-flowpath and therefore to stream discharge. Changes in the observed pH-discharge relationship over time indicate that high-flow pH has increased more rapidly than mean-flow pH, and therefore that episodes have decreased in magnitude since 1980. However a two-box application of the dynamic model MAGIC, whilst reproducing this trend, suggests that it will not persist in the long term, with mean ANC continuing to increase until 2100, but the ANC of the upper soil (the source of relatively acid water during high-flow episodes) stabilising close to zero beyond 2030. With climate change predicted to lead to an increase in maximum flows in the latter half of the century, high-flow related acid episodes may actually become more rather than less severe in the long term, although the model suggests that this effect may be small. Two other predicted climatic changes could also detrimentally impact on acid episodes: increased severity of winter "sea-salt" episodes due to higher wind speeds during winter storms; and larger sulphate pulses due to oxidation of reduced sulphur held in organic soils, during more extreme summer droughts. At the Gwy, the near-coastal location and relatively small extent of peat soils suggest that sea-salt episodes may have the greatest influence.


2018 ◽  
Vol 10 (12) ◽  
pp. 4712 ◽  
Author(s):  
Jinjia Wu ◽  
Jiansheng Qu ◽  
Hengji Li ◽  
Li Xu ◽  
Hongfen Zhang ◽  
...  

The theme of global sustainable development has changed from environmental management to climate governance, and relevant policies on climate governance urgently need to be implemented by the public. The public understanding of climate change has become the prerequisite and basis for implementing various climate change policies. In order to explore the affected factors of climate change perception among Chinese residents, this study was conducted across 31 provinces and regions of China through field household surveys and interviews. Combined with the residents’ perception of climate change with the possible affected factors, the related factors affecting Chinese residents’ perception of climate change were explored. The results show that the perceptive level of climate change of Chinese residents is related to the education level and the household size of residents. Improving public awareness of climate change risk in the context of climate change through multiple channels will also help to improve residents’ awareness of climate change. On the premise of improving the level of national education, improving education on climate change in school education and raising awareness of climate change risk among dependents will help to improve the level of Chinese residents’ awareness of climate change, which could be instrumental in promoting public participation in climate change mitigation and adaptation actions.


2019 ◽  
Vol 25 ◽  
pp. 5-19
Author(s):  
María J. Gunnarsdóttir ◽  
Sigurður Magnús Garðarsson ◽  
Hrund Ólöf Andradóttir ◽  
Alfreð Schiöth

Climate change is expected to have impact on water supply and drinking water quality in Iceland. Foremost there are three influential weather-related factors; increase in temperature; rise in sea level; and seasonal and regional change in precipitation in both quantity and intensity. In this study international and local reports and articles were analyzed for expected impact on the water resource with emphasis on the northern and the arctic region. Water quality risk factors were analyzed based on surveillance data of the water supplies from the Local Competent Authorities. Preliminary risk assessment of landslides and flooding was performed in one surveillance area in northern Iceland.


2021 ◽  
Author(s):  
Sophie de Bruin ◽  
Jannis Hoch ◽  
Nina von Uexkull ◽  
Halvard Buhaug ◽  
Nico Wanders

<p>The socioeconomic impacts of changes in climate-related and hydrology-related factors are increasingly acknowledged to affect the on-set of violent conflict. Full consensus upon the general mechanisms linking these factors with conflict is, however, still limited. The absence of full understanding of the non-linearities between all components and the lack of sufficient data make it therefore hard to address violent conflict risk on the long-term. </p><p>Although it is neither desirable nor feasible to make exact predictions, projections are a viable means to provide insights into potential future conflict risks and uncertainties thereof. Hence, making different projections is a legitimate way to deal with and understand these uncertainties, since the construction of diverse scenarios delivers insights into possible realizations of the future.  </p><p>Through machine learning techniques, we (re)assess the major drivers of conflict for the current situation in Africa, which are then applied to project the regions-at-risk following different scenarios. The model shows to accurately reproduce observed historic patterns leading to a high ROC score of 0.91. We show that socio-economic factors are most dominant when projecting conflicts over the African continent. The projections show that there is an overall reduction in conflict risk as a result of increased economic welfare that offsets the adverse impacts of climate change and hydrologic variables. It must be noted, however, that these projections are based on current relations. In case the relations of drivers and conflict change in the future, the resulting regions-at-risk may change too.   By identifying the most prominent drivers, conflict risk mitigation measures can be tuned more accurately to reduce the direct and indirect consequences of climate change on the population in Africa. As new and improved data becomes available, the model can be updated for more robust projections of conflict risk in Africa under climate change.</p>


Author(s):  
Y Widodo ◽  
S Wahyuningsih ◽  
JS Utomo ◽  
A Subagio

Green revolution started at mid of twentieth century was the answer of anxiousness reminded by Malthusian that food scarcity problems in relation with population growth. In concurrence with exploitation of fossil fuel for agriculture mechanization as well as agrochemicals in the form of inorganic fertilizer and pesticide, green revolution by introducing high yielding varieties of cereals and grains was able to nourish the world population by increasing productivity. Indeed, from beginning of mechanization with fossil fuel based as advised by Rudolf Diesel then Arrhenius would be affected to the release of CO2 to the atmosphere and consequently exaggerating climate change as suffered by current and future generations. Under green revolution based on cereals and grains affected forest conversion into open agricultural land, because both commodities are sun-loving crops, which are hate to the shade. On the other hand, to slow the severity of climate change natural forest must be conserved tightly. Entering third millennium demand of food production with ecologically friendly is stronger. Hence, green revolution needs to be amended into greener perspectives. Thus, implementation of agro-forestry into wide range of agro-ecological zone is urgently innovated. Fortunately, shade tolerant of root crops has significant advantage to be developed under agro-forestry. Under shade of forest canopy at basal forest strata, root crops are able to sequester CO2 to be converted into carbohydrate and other compounds to provide food for the dweller. Back to nature is not only a slogan, with root crops under agro-forestry is a reality; fresh root up to 30 t ha-1 can be harvested yearly as the source of food and renewable fuel as well. This potential is very worthy to improve and greening the existing green revolution to be more sustainable.Int. J. Agril. Res. Innov. & Tech. 8 (1): 26-37, June, 2018


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