Air pollution mitigation and global dimming: a challenge to agriculture under changing climate

Abstract. We apply different aerosol and aerosol precursor emission scenarios reflecting possible future control strategies for air pollution in the ECHAM5-HAM model, and simulate the resulting effect on the Earth's radiation budget. We use two opposing future mitigation strategies for the year 2030: one in which emission reduction legislation decided in countries throughout the world are effectively implemented (current legislation; CLE 2030) and one in which all technical options for emission reductions are being implemented independent of their cost (maximum feasible reduction; MFR 2030). We consider the direct, semi-direct and indirect radiative effects of aerosols. The total anthropogenic aerosol radiative forcing defined as the difference in the top-of-the-atmosphere radiation between 2000 and pre-industrial times amounts to −2.00 W/m2. In the future this negative global annual mean aerosol radiative forcing will only slightly change (+0.02 W/m2) under the "current legislation" scenario. Regionally, the effects are much larger: e.g. over Eastern Europe radiative forcing would increase by +1.50 W/m2 because of successful aerosol reduction policies, whereas over South Asia it would decrease by −1.10 W/m2 because of further growth of emissions. A "maximum feasible reduction" of aerosols and their precursors would lead to an increase of the global annual mean aerosol radiative forcing by +1.13 W/m2. Hence, in the latter case, the present day negative anthropogenic aerosol forcing could be more than halved by 2030 because of aerosol reduction policies and climate change thereafter will be to a larger extent be controlled by greenhouse gas emissions. We combined these two opposing future mitigation strategies for a number of experiments focusing on different sectors and regions. In addition, we performed sensitivity studies to estimate the importance of future changes in oxidant concentrations and the importance of the aerosol microphysical coupling within the range of expected future changes. For changes in oxidant concentrations caused by future air pollution mitigation, we do not find a significant effect for the global annual mean radiative aerosol forcing. In the extreme case of only abating SO2 or carbonaceous emissions to a maximum feasible extent, we find deviations from additivity for the radiative forcing over anthropogenic source regions up to 10% compared to an experiment abating both at the same time.

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Spatio-Temporal Variations of Multiple Primary Air Pollutants Emissions in Beijing of China, 2006–2015

Atmosphere ◽

10.3390/atmos10090494 ◽

2019 ◽

Vol 10 (9) ◽

pp. 494 ◽

Cited By ~ 1

Author(s):

Yifeng Xue ◽

Shihao Zhang ◽

Zhen Zhou ◽

Kun Wang ◽

Kaiyun Liu ◽

...

Keyword(s):

Air Pollution ◽

Quality Improvement ◽

Air Quality ◽

Air Pollutants ◽

Clean Energy ◽

Mitigation Measures ◽

Source Control ◽

Energy Structure ◽

Pollution Mitigation ◽

Air Quality Improvement

Air pollution in Beijing, China has attracted continuous worldwide public attention along with the rapid urbanization of the city. By implementing a set of air pollution mitigation measures, the air quality of Beijing has been gradually improved in recent years. In this study, the intrinsic factors leading to air quality improvement in Beijing are studied via a quantitative evaluation of the temporal and spatial changes in emissions of primary air pollutants over the past ten years. Based on detailed activity levels of each economic sector and a localized database containing source and pollutant specific emission factors, an integrated emissions inventory of primary air pollutants discharged from various sources between 2006 and 2015 is established. With the implementation of phased air pollution mitigation measures, and the Clean Air Action Plan, the original coal-dominated energy structure in Beijing has undergone tremendous changes, resulting in the substantial reduction of multiple air pollutants. The total of emissions of six major atmospheric pollutants (PM10, PM2.5, SO2, NOX, VOCs and NH3) in Beijing decreased by 35% in 2015 compared to 2006—this noticeable decrease was well consistent with the declining trend of ambient concentration of criterion air pollutants (SO2, PM10, PM2.5 and NO2) and air quality improvement, thus showing a good correlation between the emission of air pollutants and the outcome of air quality. SO2 emission declined the most, at about 71.7%, which was related to the vigorous promotion of combustion source control, such as the shutdown of coal-fired facilities and domestic stoves and transition to clean energy, like natural gas or electricity. Emissions of PM decreased considerably (by 48%) due to energy structure optimization, industrial structure adjustments, and end-of-pipe PM source control. In general, NOX, NH3, and VOCs decreased relatively slightly, by 25%, 14%, and 2%, respectively, and accordingly, they represented the limiting factors for improving air quality and the key points of air pollution mitigation in Beijing for the future.

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Urbanization effect on sunshine duration during global dimming and brightening periods in China

10.5194/acp-2016-657 ◽

2016 ◽

Cited By ~ 1

Author(s):

Yawen Wang ◽

Martin Wild ◽

Arturo Sanchez-Lorenzo ◽

Yonghui Yang ◽

Veronica Manara ◽

...

Keyword(s):

Air Pollution ◽

Rural Areas ◽

Average Rate ◽

Sunshine Duration ◽

Regional Scale ◽

Urbanization Effect ◽

Surface Solar Radiation ◽

Decadal Variations ◽

Global Dimming ◽

Urban And Rural Areas

Abstract. There is an ongoing debate on whether the observed decadal variations in surface solar radiation, known as "dimming and brightening", are a global or just local phenomenon. We investigated this issue using a comprehensive set of long-term sunshine duration records from China, which experienced a rapid growth in urbanization during past decades. 172 pairs of urban and nearby rural stations were analyzed over the period 1960–1989 ("dimming phase") and 1990–2013 ("brightening phase"). There is a large overlap in urban and rural sunshine duration trends for both dimming (≈ 86 %) and brightening (≈ 84 %) phases. This indicates that rather than urban dimming or rural brightening, the global dimming and brightening phenomena are more of national/regional scale in China. In the dimming phase, sunshine duration significantly declined in both urban and rural areas at an average rate of −0.20 h d−1 decade−1 and −0.14 h d−1 decade−1 respectively, i.e. rural dimming has been around two-thirds of urban dimming. This ratio generally increases from a minimum of 0.39 to a maximum of 0.87 with increasing indices of urbanization, reaching saturation when the urbanization level exceeds 50 %, or the urban population exceeds 20 million persons, or the population density becomes higher than 250 person km−2. Urbanization can be treated as a useful indicator for anthropogenic air pollution in studying pollution-driven changes in sunshine duration during the dimming phase when pollution control and monitoring were largely absent. After the transition into the brightening phase, the increasing number of environment-related laws and regulations as well as investments in the abatement of environmental pollution might have helped in counteracting air pollutants generated during the urbanization process. Therefore, in the brightening phase, urbanization no longer simply indicates an increase in air pollution and its effect on sunshine duration becomes insignificant. In conclusion, urbanization can give a general indication of pollution-driven sunshine dimming until pollution regulations become effective.

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Erratum to “Projecting future air pollution-related mortality under a changing climate: Progress, uncertainties and research needs” [Environment International 75 (2015): 21–32]

Environment International ◽

10.1016/j.envint.2014.12.005 ◽

2015 ◽

Vol 76 ◽

pp. 106-109

Author(s):

Lina Madaniyazi ◽

Yuming Guo ◽

Weiwei Yu ◽

Shilu Tong

Keyword(s):

Air Pollution ◽

Research Needs ◽

Changing Climate ◽

Future Air Pollution ◽

Related Mortality

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Air pollution mitigation by urban greening

Italus Hortus ◽

10.26353/j.itahort/2018.1.1322 ◽

2018 ◽

pp. 13 ◽

Cited By ~ 1

Author(s):

Roberta Mori

Keyword(s):

Air Pollution ◽

Urban Greening ◽

Pollution Mitigation

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The role of aerosol in altering North Atlantic atmospheric circulation in winter and air-quality feedbacks

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-22477-2014 ◽

2014 ◽

Vol 14 (16) ◽

pp. 22477-22506 ◽

Cited By ~ 1

Author(s):

F. S. R. Pausata ◽

M. Gaetani ◽

G. Messori ◽

S. Kloster ◽

F. J. Dentener

Keyword(s):

Air Pollution ◽

Air Quality ◽

Atmospheric Circulation ◽

North Atlantic ◽

Radiation Budget ◽

Atlantic Sector ◽

Pollution Mitigation ◽

Near Future ◽

Future Air Pollution

Abstract. Numerical model scenarios of future climate depict a global increase in temperatures and changing precipitation patterns, driven by increasing greenhouse gas (GHG) concentrations. Aerosol concentrations also play an important role in altering Earth's radiation budget and consequently surface temperature. Here, we use the general circulation aerosol model ECHAM5-HAM, coupled to a mixed layer ocean model, to investigate the impacts of future air pollution mitigation strategies in Europe on winter atmospheric circulation over the North Atlantic. We analyze the extreme case of a maximum feasible end-of-pipe reduction of aerosols in the near future (2030), in combination with increasing GHG concentrations. Our results show a more positive North Atlantic Oscillation (NAO) mean state in the near future, together with a significant eastward shift of the southern centre of action of the sea level pressure (SLP). Moreover, we show a significantly increased blocking frequency over the western Mediterranean. By separating the aerosol and GHG impacts, our study suggests that the aerosol abatement in the near future may be the primary driver of such circulation changes. All these concomitant modifications of the atmospheric circulation over the Euro-Atlantic sector lead to more stagnant weather conditions that favor air pollutant accumulation in the Mediterranean, especially in the western sector. These changes in atmospheric circulation should be included in future air pollution mitigation assessments. Our results suggest that an evaluation of NAO changes in individual climate model simulations will allow an objective assessment of the role of changes in wintertime circulation on future air quality.

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The Solar Radiation Climate of Greece

Climate ◽

10.3390/cli9120183 ◽

2021 ◽

Vol 9 (12) ◽

pp. 183

Author(s):

Harry D. Kambezidis

Keyword(s):

Air Pollution ◽

Solar Radiation ◽

Sunspot Cycle ◽

Absorption Index ◽

Regression Equations ◽

Diffuse Fraction ◽

Global Dimming ◽

Definition Of ◽

Negative Linear Relationship ◽

Of Greece

The solar radiation climate of Greece is investigated by using typical meteorological years (TMYs) at 43 locations in Greece based on a period of 10 years (2007–2016). These TMYs include hourly values of global, Hg, and diffuse, Hd, horizontal irradiances from which the direct, Hb, horizontal irradiance is estimated. Use of the diffuse fraction, kd, and the definition of the direct-beam fraction, kb, is made. Solar maps of annual mean Hg, Hd, kd, and kb are prepared over Greece under clear and all skies, which show interesting but explainable patterns. Additionally, the intra-annual and seasonal variabilities of these parameters are presented and regression equations are provided. It is found that Hb has a negative linear relationship with kd; the same applies to Hg with respect to kd or with respect to the latitude of the site. It is shown that kd (kb) can reflect the scattering (absorption) effects of the atmosphere on solar radiation, and, therefore, this parameter can be used as a scattering (absorption) index. An analysis shows that the influence of solar variability (sunspot cycle) on the Hg levels over Athens in the period 1953–2018 was less dominant than the anthropogenic (air-pollution) footprint that caused the global dimming effect.

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