Climate/chemistry feedbacks and biogenic emissions

2007 ◽  
Vol 365 (1856) ◽  
pp. 1727-1740 ◽  
Author(s):  
John A Pyle ◽  
Nicola Warwick ◽  
Xin Yang ◽  
Paul J Young ◽  
Guang Zeng
Keyword(s):  
Surface Ozone ◽  
Future Climate ◽  
Tropospheric Chemistry ◽  
Biogenic Emissions ◽  
Anthropogenic Emissions ◽  
Model Calculations ◽  
The Future ◽  
The Tropics ◽  
The Impact

The oxidizing capacity of the atmosphere is affected by anthropogenic emissions and is projected to change in the future. Model calculations indicate that the change in surface ozone at some locations could be large and have significant implications for human health. The calculations depend on the precise scenarios used for the anthropogenic emissions and on the details of the feedback processes included in the model. One important factor is how natural biogenic emissions will change in the future. We carry out a sensitivity calculation to address the possible increase in isoprene emissions consequent on increased surface temperature in a future climate. The changes in ozone are significant but depend crucially on the background chemical regime. In these calculations, we find that increased isoprene will increase ozone in the Northern Hemisphere but decrease ozone in the tropics. We also consider the role of bromine compounds in tropospheric chemistry and consider cases where, in a future climate, the impact of bromine could change.

scholarly journals How to most effectively expand the global surface ozone observing network

2015 ◽  
Vol 15 (15) ◽  
pp. 21025-21061
Author(s):  
E. D. Sofen ◽  
D. Bowdalo ◽  
M. J. Evans
Keyword(s):  
Atmospheric Chemistry ◽  
Surface Ozone ◽  
Tropospheric Chemistry ◽  
Atmospheric Composition ◽  
Model Assessment ◽  
Air Masses ◽  
The Cost ◽  
The Tropics ◽  
The Impact ◽  
Global Surface

Abstract. Surface ozone observations with modern instrumentation have been made around the world for almost 50 years. Some of these observations have been made as one-off activities with short term, specific science objectives and some have been made as part of wider networks which have provided a foundational infrastructure of data collection, calibration, quality control and dissemination. These observations provide a fundamental underpinning to our understanding of tropospheric chemistry, air quality policy, atmosphere-biosphere interactions, etc. Sofen et al. (2015) brought together 8 of these networks to provide a single dataset of surface ozone observations. We investigate how representative this combined dataset is of global surface ozone using the output from a global atmospheric chemistry model. We estimate that on an area basis, 25 % of the globe is observed (34 % land, 21 % ocean). Whereas Europe and North America have almost complete coverage, other continents such as Africa, South America and Asia (12–17 %) show significant gaps. Antarctica is surprisingly well observed (78 %). Little monitoring occurs over the oceans with the tropical and southern oceans particularly poorly represented. The surface ozone over key biomes such as tropical forests and savanna is almost completely unmonitored. A chemical cluster analysis suggests that a significant number of observations are made of polluted air masses, but cleaner air masses whether over the land or ocean (especially again in the tropics) are significantly under observed. The current network is unlikely to see the impact of ENSO but may be capable of detecting other planetary scale signals. Model assessment and validation activities are hampered by a lack of observations in regions where they models differ substantially, as is the ability to monitor likely changes in surface ozone over the next century. Using our methodology we are able to suggest new sites which would help to close the gap in our ability to measure global surface ozone. An additional 20 surface ozone monitoring sites (a 20 % increase in the WMO GAW ozone sites or a 1 % increase in the total background network) located on 10 islands and in 10 continental regions would almost double the area observed. The cost of this addition to the network is small compared to other expenditure on atmospheric composition research infrastructure and would provide a significant long term benefit to our understanding of the composition of the atmosphere and in the development of policy.

scholarly journals The influence of African air pollution on regional and global tropospheric ozone

2007 ◽  
Vol 7 (5) ◽  
pp. 1193-1212 ◽  
Author(s):  
A. M. Aghedo ◽  
M. G. Schultz ◽  
S. Rast
Keyword(s):  
Central Asia ◽  
Biomass Burning ◽  
Ozone Concentration ◽  
Tropospheric Ozone ◽  
Surface Ozone ◽  
The United States ◽  
Biogenic Emissions ◽  
Anthropogenic Emissions ◽  
The Impact ◽  
Surface Ozone Concentration

Abstract. We investigate the influence of African biomass burning, biogenic, lightning and anthropogenic emissions on the tropospheric ozone over Africa and globally using a coupled global chemistry climate model. Our model studies indicate that surface ozone concentration may rise by up to 50 ppbv in the burning region during the biomass burning seasons. Biogenic emissions yield between 5–30 ppbv increase in the near surface ozone concentration over tropical Africa. The impact of lightning on surface ozone is negligible, while anthropogenic emissions yield a maximum of 7 ppbv increase in the annual-mean surface ozone concentration over Nigeria, South Africa and Egypt. Our results show that biogenic emissions are the most important African emission source affecting total tropospheric ozone. The influence of each of the African emissions on the global tropospheric ozone burden (TOB) of 384 Tg yields about 9.5 Tg, 19.6 Tg, 9.0 Tg and 4.7 Tg for biomass burning, biogenic, lightning and anthropogenic emissions emitted in Africa respectively. The impact of each of these emission categories on African TOB of 33 Tg is 2.5 Tg, 4.1 Tg, 1.75 Tg and 0.89 Tg respectively, which together represents about 28% of the total TOB calculated over Africa. Our model calculations also suggest that more than 70% of the tropospheric ozone produced by each of the African emissions is found outside the continent, thus exerting a noticeable influence on a large part of the tropical troposphere. Apart from the Atlantic and Indian Ocean, Latin America experiences the largest impact of African emissions, followed by Oceania, the Middle East, Southeast and south-central Asia, northern North America (i.e. the United States and Canada), Europe and north-central Asia, for all the emission categories.

The Role of Oil and Gas in the Economic Development of the Global Economy

2018 ◽  
Author(s):  
Paul Stevens
Keyword(s):  
Economic Development ◽  
Global Economy ◽  
Oil And Gas ◽  
Primary Energy ◽  
Oil And Gas Producers ◽  
The Future ◽  
History Of ◽  
Factor Inputs ◽  
The Impact

This chapter is concerned with the role of oil and gas in the economic development of the global economy. It focuses on the context in which established and newer oil and gas producers in developing countries must frame their policies to optimize the benefits of such resources. It outlines a history of the issue over the last twenty-five years. It considers oil and gas as factor inputs, their role in global trade, the role of oil prices in the macroeconomy and the impact of the geopolitics of oil and gas. It then considers various conventional views of the future of oil and gas in the primary energy mix. Finally, it challenges the drivers behind these conventional views of the future with an emphasis on why they may prove to be different from what is expected and how this may change the context in which producers must frame their policy responses.

scholarly journals Determining the Role of Acidity, Fate and Formation of IEPOX-Derived SOA in CMAQ

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 707
Author(s):  
Petros Vasilakos ◽  
Yongtao Hu ◽  
Armistead Russell ◽  
Athanasios Nenes
Keyword(s):  
Significant Influence ◽  
Organic Aerosol ◽  
Liquid Water Content ◽  
Anthropogenic Emissions ◽  
So2 Emissions ◽  
Aerosol Acidity ◽  
A Value ◽  
Future Emission ◽  
The Impact

Formation of aerosol from biogenic hydrocarbons relies heavily on anthropogenic emissions since they control the availability of species such as sulfate and nitrate, and through them, aerosol acidity (pH). To elucidate the role that acidity and emissions play in regulating Secondary Organic Aerosol (SOA), we utilize the 2013 Southern Oxidant and Aerosol Study (SOAS) dataset to enhance the extensive mechanism of isoprene epoxydiol (IEPOX)-mediated SOA formation implemented in the Community Multiscale Air Quality (CMAQ) model (Pye et al., 2013), which was then used to investigate the impact of potential future emission controls on IEPOX OA. We found that the Henry’s law coefficient for IEPOX was the most impactful parameter that controls aqueous isoprene OA products, and a value of 1.9 × 107 M atm−1 provides the best agreement with measurements. Non-volatile cations (NVCs) were found in higher-than-expected quantities in CMAQ and exerted a significant influence on IEPOX OA by reducing its production by as much as 30% when present. Consistent with previous literature, a strong correlation of isoprene OA with sulfate, and little correlation with acidity or liquid water content, was found. Future reductions in SO2 emissions are found to not affect this correlation and generally act to increase the sensitivity of IEPOX OA to sulfate, even in extreme cases.

scholarly journals Predictive Role of Caregiver Type, Dependency Level and Time Caring on the Impact of Caring for a Dependent Relative as a Stressor

2014 ◽  
Vol 4 (3) ◽  
pp. 193-202
Author(s):  
Teresa Lanzón Serra ◽  
Amelia Díaz Martínez
Keyword(s):  
Lower Risk ◽  
Lower Number ◽  
Stress Symptoms ◽  
The Future ◽  
Predictive Role ◽  
Professional Nurses ◽  
The Impact ◽  
At Home

This work presents the evaluation of the stress symptoms associated to the task of caring for a dependent relative at home. The role played by variables such as type of caregiver (nurse/non-nurse), the relative dependency level, the number of hours per day dedicated to caring and the years the caregiver had been caring for the relative was studied. The sample was made up of 100 caregivers, and the variables associated to stress studied in the present work were intrusion, avoidance and activation. Results showed that non-nurse caregivers caring for a low dependency relative for a period of less than two years were those suffering a higher impact, with more symptoms associated to stress. Hours caring per day worked as a protective variable of stress, in that those caregivers dedicating a lower number of hours to caring had lower risk of suffering stress symptoms. These results clearly show the stressful impact of the first stages of dependency, even at the lowest level of dependency in a relative, on non-professional caregivers and highlight the need to provide strategies, similar to those shown by professional nurses looking after their own relatives, to reduce stress. This kind of intervention would prepare the caregiver for the future stages when the dependency level in the relatives and the effort caring for them would be higher.

scholarly journals Evaluating the role of contracting and expanding rainforest in initiating cycles of speciation across the Isthmus of Panama

2012 ◽  
Vol 279 (1742) ◽  
pp. 3520-3526 ◽  
Author(s):  
Brian Tilston Smith ◽  
Amei Amei ◽  
John Klicka
Keyword(s):  
Bird Species ◽  
Tropical Regions ◽  
Isthmus Of Panama ◽  
Species Pairs ◽  
The Matrix ◽  
High Species Richness ◽  
The Rich ◽  
The Tropics ◽  
The Impact

Climatic and geological changes across time are presumed to have shaped the rich biodiversity of tropical regions. However, the impact climatic drying and subsequent tropical rainforest contraction had on speciation has been controversial because of inconsistent palaeoecological and genetic data. Despite the strong interest in examining the role of climatic change on speciation in the Neotropics there has been few comparative studies, particularly, those that include non-rainforest taxa. We used bird species that inhabit humid or dry habitats that dispersed across the Panamanian Isthmus to characterize temporal and spatial patterns of speciation across this barrier. Here, we show that these two assemblages of birds exhibit temporally different speciation time patterns that supports multiple cycles of speciation. Evidence for these cycles is further corroborated by the finding that both assemblages consist of ‘young’ and ‘old’ species, despite dry habitat species pairs being geographically more distant than pairs of humid habitat species. The matrix of humid and dry habitats in the tropics not only allows for the maintenance of high species richness, but additionally this study suggests that these environments may have promoted speciation. We conclude that differentially expanding and contracting distributions of dry and humid habitats was probably an important contributor to speciation in the tropics.

scholarly journals How will future climate depending agronomic management impact the yield risk of wheat cropping systems? A regional case study of Eastern Denmark

2021 ◽  
pp. 1-16
Author(s):  
J. Macholdt ◽  
J. Glerup Gyldengren ◽  
E. Diamantopoulos ◽  
M. E. Styczen
Keyword(s):  
Climate Change ◽  
Crop Production ◽  
Cropping Systems ◽  
Future Climate ◽  
Catch Crops ◽  
Agronomic Management ◽  
The Future ◽  
Yield Risk ◽  
Management Factors ◽  
The Impact

Abstract One of the major challenges in agriculture is how climate change influences crop production, for different environmental (soil type, topography, groundwater depth, etc.) and agronomic management conditions. Through systems modelling, this study aims to quantify the impact of future climate on yield risk of winter wheat for two common soil types of Eastern Denmark. The agro-ecosystem model DAISY was used to simulate arable, conventional cropping systems (CSs) and the study focused on the three main management factors: cropping sequence, usage of catch crops and cereal straw management. For the case region of Eastern Denmark, the future yield risk of wheat does not necessarily increase under climate change mainly due to lower water stress in the projections; rather, it depends on appropriate management and each CS design. Major management factors affecting the yield risk of wheat were N supply and the amount of organic material added during rotations. If a CS is characterized by straw removal and no catch crop within the rotation, an increased wheat yield risk must be expected in the future. In contrast, more favourable CSs, including catch crops and straw incorporation, maintain their capacity and result in a decreasing yield risk over time. Higher soil organic matter content, higher net nitrogen mineralization rate and higher soil organic nitrogen content were the main underlying causes for these positive effects. Furthermore, the simulation results showed better N recycling and reduced nitrate leaching for the more favourable CSs, which provide benefits for environment-friendly and sustainable crop production.

scholarly journals A simulation study on the effect of climate change on crop water use and chill unit accumulation

2017 ◽  
Vol 113 (7/8) ◽  
Author(s):  
Abiodun A. Ogundeji ◽  
Henry Jordaan
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Water Use ◽  
Irrigation System ◽  
Future Climate ◽  
Crop Water ◽  
Crop Water Use ◽  
Chill Unit ◽  
The Future ◽  
The Impact

Climate change and its impact on already scarce water resources are of global importance, but even more so for water scarce countries. Apart from the effect of climate change on water supply, the chill unit requirement of deciduous fruit crops is also expected to be affected. Although research on crop water use has been undertaken, researchers have not taken the future climate into consideration. They also have focused on increasing temperatures but failed to relate temperature to chill unit accumulation, especially in South Africa. With a view of helping farmers to adapt to climate change, in this study we provide information that will assist farmers in their decision-making process for adaptation and in the selection of appropriate cultivars of deciduous fruits. Crop water use and chill unit requirements are modelled for the present and future climate. Results show that, irrespective of the irrigation system employed, climate change has led to increases in crop water use. Water use with the drip irrigation system was lower than with sprinkler irrigation as a result of efficiency differences in the irrigation technologies. It was also confirmed that the accumulated chill units will decrease in the future as a consequence of climate change. In order to remain in production, farmers need to adapt to climate change stress by putting in place water resources and crop management plans. Thus, producers must be furnished with a variety of adaptation or management strategies to overcome the impact of climate change.

scholarly journals An evaluation of the effect of future climate on runoff in the Dongjiang River basin, South China

2015 ◽  
Vol 368 ◽  
pp. 257-262
Author(s):  
K. Lin ◽  
W. Zhai ◽  
S. Huang ◽  
Z. Liu
Keyword(s):  
Climate Change ◽  
River Basin ◽  
South China ◽  
Annual Runoff ◽  
Future Climate ◽  
Weather Data ◽  
Future Climate Change ◽  
Dongjiang River ◽  
The Future ◽  
The Impact

Abstract. The impact of future climate change on the runoff for the Dongjiang River basin, South China, has been investigated with the Soil and Water Assessment Tool (SWAT). First, the SWAT model was applied in the three sub-basins of the Dongjiang River basin, and calibrated for the period of 1970–1975, and validated for the period of 1976–1985. Then the hydrological response under climate change and land use scenario in the next 40 years (2011–2050) was studied. The future weather data was generated by using the weather generators of SWAT, based on the trend of the observed data series (1966–2005). The results showed that under the future climate change and LUCC scenario, the annual runoff of the three sub-basins all decreased. Its impacts on annual runoff were –6.87%, –6.54%, and –18.16% for the Shuntian, Lantang, and Yuecheng sub-basins respectively, compared with the baseline period 1966–2005. The results of this study could be a reference for regional water resources management since Dongjiang River provides crucial water supplies to Guangdong Province and the District of Hong Kong in China.

scholarly journals Enhancement of secondary aerosol formation by reduced anthropogenic emissions during Spring Festival 2019 and enlightenment for regional PM<sub>2.5</sub> control in Beijing

2020 ◽  
Author(s):  
Yuying Wang ◽  
Zhanqing Li ◽  
Qiuyan Wang ◽  
Xiaoai Jin ◽  
Peng Yan ◽  
...  
Keyword(s):  
Particle Number ◽  
Surface Ozone ◽  
Sulfur Oxidation ◽  
Anthropogenic Emissions ◽  
Aerosol Formation ◽  
Spring Festival ◽  
Sulfate Formation ◽  
Oxidation Ratio ◽  
The Impact ◽  
Mass Concentrations

Abstract. A comprehensive field experiment measuring aerosol chemical and physical properties at a suburban site in Beijing around the 2019 Spring Festival was carried out to investigate the impact of reduced anthropogenic emissions on aerosol formation. Sharply reduced sulfur dioxide (SO2) and nitrogen dioxide (NO2) concentrations during the festival holiday resulted in an unexpected increase in the surface ozone (O3) concentration, leading to enhancement of the atmospheric oxidation capacity. Simultaneously, the reduced anthropogenic emissions resulted in massive decreases in particle number concentration at all sizes and the mass concentrations of organics and black carbon. However, the mass concentrations of inorganics (especially sulfate) decreased weakly. Detailed analyses of the sulfur oxidation ratio and the nitrogen oxidation ratio suggest that sulfate formation during the holiday could be promoted by enhanced nocturnal aqueous-phase chemical reactions between SO2 and O3 under moderate relative humidity (RH) conditions (40 % 

Sign in / Sign up

Export Citation Format

Share Document