scholarly journals Drivers of changes in stratospheric and tropospheric ozone between year 2000 and 2100

2016 ◽  
Vol 16 (5) ◽  
pp. 2727-2746 ◽  
Author(s):  
Antara Banerjee ◽  
Amanda C. Maycock ◽  
Alexander T. Archibald ◽  
N. Luke Abraham ◽  
Paul Telford ◽  
...  
Keyword(s):  
Climate Change ◽  
Greenhouse Gases ◽  
Tropospheric Ozone ◽  
Climate Forcing ◽  
Atmospheric Response ◽  
Chemical Production ◽  
The United Kingdom ◽  
Ozone Precursor ◽  
Ozone Depleting Substances ◽  
Year 2000

Abstract. A stratosphere-resolving configuration of the Met Office's Unified Model (UM) with the United Kingdom Chemistry and Aerosols (UKCA) scheme is used to investigate the atmospheric response to changes in (a) greenhouse gases and climate, (b) ozone-depleting substances (ODSs) and (c) non-methane ozone precursor emissions. A suite of time-slice experiments show the separate, as well as pairwise, impacts of these perturbations between the years 2000 and 2100. Sensitivity to uncertainties in future greenhouse gases and aerosols is explored through the use of the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios. The results highlight an important role for the stratosphere in determining the annual mean tropospheric ozone response, primarily through stratosphere–troposphere exchange (STE) of ozone. Under both climate change and reductions in ODSs, increases in STE offset decreases in net chemical production and act to increase the tropospheric ozone burden. This opposes the effects of projected decreases in ozone precursors through measures to improve air quality, which act to reduce the ozone burden. The global tropospheric lifetime of ozone (τO3) does not change significantly under climate change at RCP4.5, but it decreases at RCP8.5. This opposes the increases in τO3 simulated under reductions in ODSs and ozone precursor emissions. The additivity of the changes in ozone is examined by comparing the sum of the responses in the single-forcing experiments to those from equivalent combined-forcing experiments. Whilst the ozone responses to most forcing combinations are found to be approximately additive, non-additive changes are found in both the stratosphere and troposphere when a large climate forcing (RCP8.5) is combined with the effects of ODSs.

scholarly journals Drivers of changes in stratospheric and tropospheric ozone between year 2000 and 2100

2015 ◽  
Vol 15 (21) ◽  
pp. 30645-30691
Author(s):  
A. Banerjee ◽  
A. C. Maycock ◽  
A. T. Archibald ◽  
N. L. Abraham ◽  
P. Telford ◽  
...  
Keyword(s):  
Climate Change ◽  
Greenhouse Gases ◽  
Tropospheric Ozone ◽  
Climate Forcing ◽  
Atmospheric Response ◽  
Chemical Production ◽  
The United Kingdom ◽  
Ozone Precursor ◽  
Ozone Depleting Substances ◽  
Year 2000

Abstract. A stratosphere-resolving configuration of the Met Office's Unified Model (UM) with the United Kingdom Chemistry and Aerosols (UKCA) scheme is used to investigate the atmospheric response to changes in (a) greenhouse gases and climate, (b) ozone-depleting substances (ODSs) and (c) non-methane ozone precursor emissions. A suite of time-slice experiments show the separate, as well as pairwise, impacts of these perturbations between the years 2000 and 2100. Sensitivity to uncertainties in future greenhouse gases and aerosols is explored through the use of the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios. The results highlight an important role for the stratosphere in determining the annual mean tropospheric ozone response, primarily through stratosphere–troposphere exchange of ozone (STE). Under both climate change and reductions in ODSs, increases in STE offset decreases in net chemical production, leading to overall increases in the tropospheric ozone burden. This opposes the effects of projected decreases in ozone precursors through measures to improve air quality, which act to reduce the ozone burden. The global tropospheric lifetime of ozone (τO3) does not change significantly under climate change at RCP4.5, but it decreases at RCP8.5. This opposes the increases in τO3 simulated under reductions in both ODSs and ozone precursor emissions. The additivity of the changes in ozone is examined by comparing the sum of the responses in the single-forcing experiments to those from equivalent combined-forcing experiments. Whilst the ozone responses to most forcing combinations are found to be approximately additive, non-additive changes are found in both the stratosphere and troposphere when a large climate forcing (RCP8.5) is combined with the effects of ODSs.

scholarly journals Chemical and climatic drivers of radiative forcing due to changes in stratospheric and tropospheric ozone over the 21st century

2018 ◽  
Vol 18 (4) ◽  
pp. 2899-2911 ◽  
Author(s):  
Antara Banerjee ◽  
Amanda C. Maycock ◽  
John A. Pyle
Keyword(s):  
Tropospheric Ozone ◽  
Radiative Forcing ◽  
Climate Model ◽  
Stratospheric Ozone ◽  
Radiative Forcings ◽  
The United Kingdom ◽  
Climatic Drivers ◽  
Ozone Precursor ◽  
Ozone Depleting Substances ◽  
Projected Changes

Abstract. The ozone radiative forcings (RFs) resulting from projected changes in climate, ozone-depleting substances (ODSs), non-methane ozone precursor emissions and methane between the years 2000 and 2100 are calculated using simulations from the UM-UKCA chemistry–climate model (UK Met Office's Unified Model containing the United Kingdom Chemistry and Aerosols sub-model). Projected measures to improve air-quality through reductions in non-methane tropospheric ozone precursor emissions present a co-benefit for climate, with a net global mean ozone RF of −0.09 W m−2. This is opposed by a positive ozone RF of 0.05 W m−2 due to future decreases in ODSs, which is driven by an increase in tropospheric ozone through stratosphere-to-troposphere transport of air containing higher ozone amounts. An increase in methane abundance by more than a factor of 2 (as projected by the RCP8.5 scenario) is found to drive an ozone RF of 0.18 W m−2, which would greatly outweigh the climate benefits of non-methane tropospheric ozone precursor reductions. A small fraction (∼ 15 %) of the ozone RF due to the projected increase in methane results from increases in stratospheric ozone. The sign of the ozone RF due to future changes in climate (including the radiative effects of greenhouse gases, sea surface temperatures and sea ice changes) is shown to be dependent on the greenhouse gas emissions pathway, with a positive RF (0.05 W m−2) for RCP4.5 and a negative RF (−0.07 W m−2) for the RCP8.5 scenario. This dependence arises mainly from differences in the contribution to RF from stratospheric ozone changes. Considering the increases in tropopause height under climate change causes only small differences (≤ |0.02| W m−2) for the stratospheric, tropospheric and whole-atmosphere RFs.

scholarly journals Chemical and climatic drivers of radiative forcing due to changes in stratospheric and tropospheric ozone over the 21<sup>st</sup> century

2017 ◽  
Author(s):  
Antara Banerjee ◽  
Amanda C. Maycock ◽  
John A. Pyle
Keyword(s):  
Greenhouse Gas ◽  
Tropospheric Ozone ◽  
Radiative Forcing ◽  
Climate Model ◽  
Stratospheric Ozone ◽  
Radiative Forcings ◽  
Climatic Drivers ◽  
Ozone Precursor ◽  
Ozone Depleting Substances ◽  
Projected Changes

Abstract. The ozone radiative forcings (RFs) resulting from projected changes in climate, ozone-depleting substances (ODSs), non-methane ozone precursor emissions and methane between the years 2000 and 2100 are calculated using simulations from the UM-UKCA chemistry-climate model. Projected measures to improve air-quality through reductions in tropospheric ozone precursor emissions present a co-benefit for climate, with a net global mean ozone RF of −0.09 Wm−2. This is opposed by a positive ozone RF of 0.07 Wm−2 due to future decreases in ODSs, which is mainly driven by an increase in tropospheric ozone through stratosphere-to-troposphere exchange. An increase in methane abundance by more than a factor of two (as projected by the RCP8.5 scenario) is found to drive an ozone RF of 0.19 Wm−2, which would greatly outweigh the climate benefits of tropospheric non-methane ozone precursor reductions. A third of the ozone RF due to the projected increase in methane results from increases in stratospheric ozone. The sign of the ozone RF due to future changes in climate (including the radiative effects of greenhouse gas concentrations, sea surface temperatures and sea ice changes) is shown to be dependent on the greenhouse gas emissions pathway, with a positive RF (0.06 Wm−2) for RCP4.5 and a negative RF (−0.07 Wm−2) for the RCP8.5 scenario. This dependence arises from differences in the contribution to RF from stratospheric ozone changes.

scholarly journals Key drivers of ozone change and its radiative forcing over the 21st century

2017 ◽  
Author(s):  
Fernando Iglesias-Suarez ◽  
Douglas E. Kinnison ◽  
Alexandru Rap ◽  
Oliver Wild ◽  
Paul J. Young
Keyword(s):  
Climate Change ◽  
21St Century ◽  
Radiative Forcing ◽  
Climate Model ◽  
Stratospheric Ozone ◽  
Atmospheric Composition ◽  
Radiative Balance ◽  
Uncertainty Range ◽  
Ozone Depleting Substances ◽  
Year 2000

Abstract. Over the 21st century changes in both tropospheric and stratospheric ozone are likely to have important consequences for the Earth's radiative balance. In this study we investigated the radiative effects of future ozone changes, using the Community Earth System Model (CESM1), with the Whole Atmosphere Community Climate Model (WACCM), and including fully coupled radiation and chemistry schemes. Using year 2100 conditions from the Representative Concentration Pathways 8.5 (RCP8.5) scenario, we quantified the individual contributions to ozone radiative forcing of (1) climate change (with and without lightning feedback), (2) reduced concentrations of ozone depleting substances (ODSs), and (3) methane increases. We calculated future ozone radiative forcing relative to year 2000 of (1) 63 ± 76 m Wm−2, (2) 129 ± 81 m Wm−2, and (3) 225 ± 85 m Wm−2, due to climate change, ODSs and methane respectively. Our best estimate of net ozone forcing in this set of simulations is 420 ± 120 m Wm−2 relative to year 2000, and 750 ± 230 m Wm−2 relative to year 1750, with uncertainty range given by approximately ±30 %. We find that the overall long-term tropospheric ozone forcing from methane chemistry-climate feedbacks related to OH and methane lifetime is small (46 m Wm−2). Ozone forcings associated with climate change and stratospheric ozone recovery are robust with regard to background conditions, even though the ozone response is sensitive to both changes in atmospheric composition and climate. Changes in stratospheric-produced ozone account for ~ 47 % of the overall radiative forcing in this set of simulations, highlighting the key role of the stratosphere in determining future radiative forcing.

scholarly journals Future changes in the stratosphere-to-troposphere ozone mass flux and the contribution from climate change and ozone recovery

2018 ◽  
Vol 18 (10) ◽  
pp. 7721-7738 ◽  
Author(s):  
Stefanie Meul ◽  
Ulrike Langematz ◽  
Philipp Kröger ◽  
Sophie Oberländer-Hayn ◽  
Patrick Jöckel
Keyword(s):  
Greenhouse Gas ◽  
Mass Flux ◽  
Tropospheric Ozone ◽  
Climate Model ◽  
Stratospheric Ozone ◽  
Ozone Production ◽  
Maximal Increase ◽  
The Future ◽  
Ozone Precursor ◽  
Ozone Depleting Substances

Abstract. Using a state-of-the-art chemistry–climate model we investigate the future change in stratosphere–troposphere exchange (STE) of ozone, the drivers of this change, as well as the future distribution of stratospheric ozone in the troposphere. Supplementary to previous work, our focus is on changes on the monthly scale. The global mean annual influx of stratospheric ozone into the troposphere is projected to increase by 53 % between the years 2000 and 2100 under the RCP8.5 greenhouse gas scenario. The change in ozone mass flux (OMF) into the troposphere is positive throughout the year with maximal increase in the summer months of the respective hemispheres. In the Northern Hemisphere (NH) this summer maximum STE increase is a result of increasing greenhouse gas (GHG) concentrations, whilst in the Southern Hemisphere(SH) it is due to equal contributions from decreasing levels of ozone depleting substances (ODS) and increasing GHG concentrations. In the SH the GHG effect is dominating in the winter months. A large ODS-related ozone increase in the SH stratosphere leads to a change in the seasonal breathing term which results in a future decrease of the OMF into the troposphere in the SH in September and October. The resulting distributions of stratospheric ozone in the troposphere differ for the GHG and ODS changes due to the following: (a) ozone input occurs at different regions for GHG- (midlatitudes) and ODS-changes (high latitudes); and (b) stratospheric ozone is more efficiently mixed towards lower tropospheric levels in the case of ODS changes, whereas tropospheric ozone loss rates grow when GHG concentrations rise. The comparison between the moderate RCP6.0 and the extreme RCP8.5 emission scenarios reveals that the annual global OMF trend is smaller in the moderate scenario, but the resulting change in the contribution of ozone with stratospheric origin (O3s) to ozone in the troposphere is of comparable magnitude in both scenarios. This is due to the larger tropospheric ozone precursor emissions and hence ozone production in the RCP8.5 scenario.

scholarly journals Contributions to stratospheric ozone changes from ozone depleting substances and greenhouse gases

2010 ◽  
Vol 10 (4) ◽  
pp. 9647-9694 ◽  
Author(s):  
D. A. Plummer ◽  
J. F. Scinocca ◽  
T. G. Shepherd ◽  
M. C. Reader ◽  
A. I. Jonsson
Keyword(s):  
Greenhouse Gases ◽  
21St Century ◽  
Climate Model ◽  
Stratospheric Ozone ◽  
Three Dimensional ◽  
Ocean Model ◽  
Residual Circulation ◽  
Chemical Effects ◽  
Ozone Depleting Substances ◽  
Year 2000

Abstract. A state-of-the-art chemistry climate model coupled to a three-dimensional ocean model is used to produce three experiments, all seamlessly covering the period 1950–2100, forced by different combinations of long-lived Greenhouse Gases (GHGs) and Ozone Depleting Substances (ODSs). The experiments are designed to investigate the mechanisms by which GHGs and ODSs affect the evolution of ozone, including changes in the Brewer-Dobson circulation of the stratosphere and cooling of the upper stratosphere by CO2. Separating the effects of GHGs and ODSs on ozone, we find the decrease in upper stratospheric ozone from ODSs up to the year 2000 is approximately 30% larger than the actual decrease in ozone due to the offsetting effects of cooling by increased CO2. Over the 21st century, as ODSs decrease, continued cooling from CO2 is projected to account for more than 50% of the projected increase in upper stratospheric ozone. Changes below 20 hPa show a redistribution of ozone from tropical to extra-tropical latitudes with an increase in the Brewer-Dobson circulation, while globally averaged the amount of ozone below 20 hPa decreases over the 21st century. Further analysis by linear regression shows that changes associated with GHGs do not appreciably alter the recovery of stratospheric ozone from the effects of ODSs; over much of the stratosphere ozone recovery follows the decline of halogen concentrations within statistical uncertainty, though the lower polar stratosphere of the Southern Hemisphere is an exception with ozone concentrations recovering more slowly than indicated by the halogen concentrations. These results also reveal the degree to which climate change, and stratospheric CO2 cooling in particular, mutes the chemical effects of N2O on ozone in the standard future scenario used for the WMO Ozone Assessment. Increases in the residual circulation of the atmosphere and chemical effects from CO2 cooling more than halve the increase in reactive nitrogen in the mid to upper stratosphere that results from the specified increase in N2O between 1950 and 2100.

Stepping on the Gas to a Circular Economy: Accelerating Development of Carbon-Negative Chemical Production from Gas Fermentation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nick Fackler ◽  
Björn D. Heijstra ◽  
Blake J. Rasor ◽  
Hunter Brown ◽  
Jacob Martin ◽  
...  
Keyword(s):  
Climate Change ◽  
Greenhouse Gases ◽  
Carbon Capture ◽  
Scale Up ◽  
Annual Review ◽  
Publication Date ◽  
Chemical Production ◽  
Gas Fermentation ◽  
Product Flexibility ◽  
Key Enabling Technologies

Owing to rising levels of greenhouse gases in our atmosphere and oceans, climate change poses significant environmental, economic, and social challenges globally. Technologies that enable carbon capture and conversion of greenhouse gases into useful products will help mitigate climate change by enabling a new circular carbon economy. Gas fermentation using carbon-fixing microorganisms offers an economically viable and scalable solution with unique feedstock and product flexibility that has been commercialized recently. We review the state of the art of gas fermentation and discuss opportunities to accelerate future development and rollout. We discuss the current commercial process for conversion of waste gases to ethanol, including the underlying biology, challenges in process scale-up, and progress on genetic tool development and metabolic engineering to expand the product spectrum. We emphasize key enabling technologies to accelerate strain development for acetogens and other nonmodel organisms. Expected final online publication date for the Annual Review of Chemical and Biomolecular Engineering, Volume 12 is June 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Drivers of the tropospheric ozone budget throughout the 21st century under the medium-high climate scenario RCP 6.0

2015 ◽  
Vol 15 (10) ◽  
pp. 5887-5902 ◽  
Author(s):  
L. E. Revell ◽  
F. Tummon ◽  
A. Stenke ◽  
T. Sukhodolov ◽  
A. Coulon ◽  
...  
Keyword(s):  
Climate Change ◽  
21St Century ◽  
Tropospheric Ozone ◽  
Climate Scenario ◽  
Climate Impacts ◽  
Air Pollutant ◽  
Tropospheric Temperature ◽  
Ozone Precursor ◽  
Lightning Nox ◽  
Global Mean

Abstract. Because tropospheric ozone is both a greenhouse gas and harmful air pollutant, it is important to understand how anthropogenic activities may influence its abundance and distribution through the 21st century. Here, we present model simulations performed with the chemistry–climate model SOCOL, in which spatially disaggregated chemistry and transport tracers have been implemented in order to better understand the distribution and projected changes in tropospheric ozone. We examine the influences of ozone precursor emissions (nitrogen oxides (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs)), climate change (including methane effects) and stratospheric ozone recovery on the tropospheric ozone budget, in a simulation following the climate scenario Representative Concentration Pathway (RCP) 6.0 (a medium-high, and reasonably realistic climate scenario). Changes in ozone precursor emissions have the largest effect, leading to a global-mean increase in tropospheric ozone which maximizes in the early 21st century at 23% compared to 1960. The increase is most pronounced at northern midlatitudes, due to regional emission patterns: between 1990 and 2060, northern midlatitude tropospheric ozone remains at constantly large abundances: 31% larger than in 1960. Over this 70-year period, attempts to reduce emissions in Europe and North America do not have an effect on zonally averaged northern midlatitude ozone because of increasing emissions from Asia, together with the long lifetime of ozone in the troposphere. A simulation with fixed anthropogenic ozone precursor emissions of NOx, CO and non-methane VOCs at 1960 conditions shows a 6% increase in global-mean tropospheric ozone by the end of the 21st century, with an 11 % increase at northern midlatitudes. This increase maximizes in the 2080s and is mostly caused by methane, which maximizes in the 2080s following RCP 6.0, and plays an important role in controlling ozone directly, and indirectly through its influence on other VOCs and CO. Enhanced flux of ozone from the stratosphere to the troposphere as well as climate change-induced enhancements in lightning NOx emissions also increase the tropospheric ozone burden, although their impacts are relatively small. Overall, the results show that under this climate scenario, ozone in the future is governed largely by changes in methane and NOx; methane induces an increase in tropospheric ozone that is approximately one-third of that caused by NOx. Climate impacts on ozone through changes in tropospheric temperature, humidity and lightning NOx remain secondary compared with emission strategies relating to anthropogenic emissions of NOx, such as fossil fuel burning. Therefore, emission policies globally have a critical role to play in determining tropospheric ozone evolution through the 21st century.

scholarly journals Developing an Integrated Model Centred on Artificial Intelligence to Effectively Predict and Analyse Climate Change Including Global Warming

2020 ◽  
Vol 10 (4) ◽  
Author(s):  
Sehaj Bedi
Keyword(s):  
Climate Change ◽  
Artificial Intelligence ◽  
Global Warming ◽  
Environmental Change ◽  
Greenhouse Gases ◽  
Average Temperature ◽  
Expected Information ◽  
Primary Test ◽  
Ozone Depleting Substances ◽  
Number Term

An increase in average temperature worldwide is called global warming. Regular occasions and human exercises are accepted to be adding to expanding normal worldwide temperatures. Long haul impacts of environmental change are continuous out of control fires, longer times of the dry season in certain areas and an increment in the number, term and power of typhoons. Global warming forecasting can be vital in the rural, energy and clinical space. This paper assesses the exhibition of a few calculations in yearly a worldwide temperature alteration anticipation from recently estimated values over the Globe. The primary test is making a solid, effective and exact information model on an enormous dataset and noticing the connection between the normal yearly temperatures and potential variables adding to Global Warming, for example, the convergence of Greenhouse gases. The information is anticipated and determined utilizing straight relapse for acquiring the most important accuracy for ozone-depleting substances and temperature contrasted with different strategies. After noticing the analysed and expected information, global warming can be reduced relatively inside a couple of years. The decrease of worldwide temperature can assist us with forestalling unsafe long-haul impacts of global warming and Climate change.

scholarly journals Lightning NO<sub>x</sub>, a key chemistry–climate interaction: impacts of future climate change and consequences for tropospheric oxidising capacity

2014 ◽  
Vol 14 (6) ◽  
pp. 8753-8778 ◽  
Author(s):  
A. Banerjee ◽  
A. T. Archibald ◽  
A. Maycock ◽  
P. Telford ◽  
N. L. Abraham ◽  
...  
Keyword(s):  
Climate Change ◽  
Tropospheric Ozone ◽  
Stratospheric Ozone ◽  
Future Climate ◽  
Ozone Production ◽  
Future Climate Change ◽  
Rcp Scenarios ◽  
Ozone Precursor ◽  
The Uk ◽  
The Impact

Abstract. Lightning is one of the major natural sources of NOx in the atmosphere. A suite of time-slice experiments using a stratosphere-resolving configuration of the Unified Model (UM), containing the UK Chemistry and Aerosols sub-model (UKCA), have been performed to investigate the impact of climate change on lightning produced NOx (LNOx) and to highlight its critical impacts on photochemical ozone production and the oxidising capacity of the troposphere. Two Representative Concentration Pathway (RCP) scenarios (RCP4.5 and RCP8.5) are explored. LNOx emissions are simulated to increase in a year-2100 climate by 33% (RCP4.5) and 78% (RCP8.5) in response to changes in convection. The total tropospheric chemical odd oxygen production (P(Ox)) increases linearly with total LNOx emissions and consequently, the tropospheric ozone burden also increases by 29 ± 4 Tg(O3) (RCP4.5) and 46 ± 4 Tg(O3) (RCP8.5). We thus show that, through changes in LNOx, the effects of climate change counteract the simulated mitigation of the ozone burden, which results from reductions in ozone precursor emissions as part of air quality controls projected in the RCP scenarios. Without the driver of increased LNOx, our simulations suggest that the net effect of climate change would be to lower free tropospheric ozone. In addition, we identify large climate-change induced enhancements in the concentration of the hydroxyl radical (OH) in the tropical upper troposphere (UT), particularly over the Maritime Continent, primarily as a consequence of larger LNOx emissions. The OH enhancement in the tropics increases oxidation of both methane (with feedbacks onto chemistry and climate) and very short-lived substances (VSLS) (with implications for stratospheric ozone depletion). We emphasise that it is important to improve our understanding of LNOx in order to gain confidence in model projections of future climate.

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