scholarly journals Tropospheric ozone radiative forcing uncertainty due to pre-industrial fire and biogenic emissions

2020 ◽  
Vol 20 (18) ◽  
pp. 10937-10951
Author(s):  
Matthew J. Rowlinson ◽  
Alexandru Rap ◽  
Douglas S. Hamilton ◽  
Richard J. Pope ◽  
Stijn Hantson ◽  
...  
Keyword(s):  
Tropospheric Ozone ◽  
Radiative Forcing ◽  
Transport Model ◽  
Radiative Transfer Model ◽  
Biogenic Emissions ◽  
Transfer Model ◽  
Terrestrial Vegetation ◽  
Uncertainty Range ◽  
Ozone Concentrations ◽  
Industrial Fire

Abstract. Tropospheric ozone concentrations are sensitive to natural emissions of precursor compounds. In contrast to existing assumptions, recent evidence indicates that terrestrial vegetation emissions in the pre-industrial era were larger than in the present day. We use a chemical transport model and a radiative transfer model to show that revised inventories of pre-industrial fire and biogenic emissions lead to an increase in simulated pre-industrial ozone concentrations, decreasing the estimated pre-industrial to present-day tropospheric ozone radiative forcing by up to 34 % (0.38 to 0.25 W m−2). We find that this change is sensitive to employing biomass burning and biogenic emissions inventories based on matching vegetation patterns, as the co-location of emission sources enhances the effect on ozone formation. Our forcing estimates are at the lower end of existing uncertainty range estimates (0.2–0.6 W m−2), without accounting for other sources of uncertainty. Thus, future work should focus on reassessing the uncertainty range of tropospheric ozone radiative forcing.

scholarly journals Tropospheric ozone radiative forcing uncertainty due to pre-industrial fire and biogenic emissions

2020 ◽  
Author(s):  
Matthew J. Rowlinson ◽  
Alexandru Rap ◽  
Douglas S. Hamilton ◽  
Richard J. Pope ◽  
Stijn Hantson ◽  
...  
Keyword(s):  
Tropospheric Ozone ◽  
Radiative Forcing ◽  
Transport Model ◽  
Radiative Transfer Model ◽  
Biogenic Emissions ◽  
Transfer Model ◽  
Terrestrial Vegetation ◽  
Uncertainty Range ◽  
Ozone Concentrations ◽  
Industrial Fire

Abstract. Tropospheric ozone concentrations are sensitive to natural emissions of precursor compounds. In contrast to existing assumptions, recent evidence indicates that terrestrial vegetation emissions in the pre-industrial were larger than in the present-day. We use a chemical transport model and a radiative transfer model to show that revised inventories of pre-industrial fire and biogenic emissions lead to an increase in simulated pre-industrial ozone concentrations, decreasing the estimated pre-industrial to present-day tropospheric ozone radiative forcing of up to 34 % (0.38 W m-2 to 0.25 W m-2). We find that this change is sensitive to employing biomass burning and biogenic emissions inventories based on matching vegetation patterns, as co-location of emission sources enhances the effect on ozone formation. Our forcing estimates are at the lower end of existing uncertainty range estimates (0.2–0.6 W m-22), without accounting for other sources of uncertainty. Thus, future work should focus on reassessing the uncertainty range of tropospheric ozone radiative forcing.

scholarly journals Air quality and radiative forcing impacts of anthropogenic volatile organic compound emissions from ten world regions

2013 ◽  
Vol 13 (8) ◽  
pp. 21125-21157 ◽  
Author(s):  
M. M. Fry ◽  
M. D. Schwarzkopf ◽  
Z. Adelman ◽  
J. J. West
Keyword(s):  
Air Quality ◽  
Tropospheric Ozone ◽  
Radiative Forcing ◽  
Transport Model ◽  
Surface Ozone ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Chemical Transport Model ◽  
Large Variability ◽  
Volatile Organic

Abstract. Non-methane volatile organic compounds (NMVOCs) influence air quality and global climate change through their effects on secondary air pollutants and climate forcers. Here we simulate the air quality and radiative forcing (RF) impacts of changes in ozone, methane, and sulfate from halving anthropogenic NMVOC emissions globally and from 10 regions individually, using a global chemical transport model and a standalone radiative transfer model. Halving global NMVOC emissions decreases global annual average tropospheric methane and ozone by 36.6 ppbv and 3.3 Tg, respectively, and surface ozone by 0.67 ppbv. All regional reductions slow the production of PAN, resulting in regional to intercontinental PAN decreases and regional NOx increases. These NOx increases drive tropospheric ozone increases nearby or downwind of source regions in the Southern Hemisphere (South America, Southeast Asia, Africa, and Australia). Some regions' NMVOC emissions contribute importantly to air pollution in other regions, such as East Asia, Middle East, and Europe, whose impact on US surface ozone is 43%, 34%, and 34% of North America's impact. Global and regional NMVOC reductions produce widespread negative net RFs (cooling) across both hemispheres from tropospheric ozone and methane decreases, and regional warming and cooling from changes in tropospheric ozone and sulfate (via several oxidation pathways). The total global net RF for NMVOCs is estimated as 0.0277 W m−2 (~1.8% of CO2 RF since the preindustrial). The 100 yr and 20 yr global warming potentials (GWP100, GWP20) are 2.36 and 5.83 for the global reduction, and 0.079 to 6.05 and −1.13 to 18.9 among the 10 regions. The NMVOC RF and GWP estimates are generally lower than previously modeled estimates, due to differences among models in ozone, methane, and sulfate sensitivities, and the climate forcings included in each estimate. Accounting for a~fuller set of RF contributions may change the relative magnitude of each region's impacts. The large variability in the RF and GWP of NMVOCs among regions suggest that regionally-specific metrics may be necessary to include NMVOCs in multi-gas climate trading schemes.

scholarly journals Air quality and radiative forcing impacts of anthropogenic volatile organic compound emissions from ten world regions

2014 ◽  
Vol 14 (2) ◽  
pp. 523-535 ◽  
Author(s):  
M. M. Fry ◽  
M. D. Schwarzkopf ◽  
Z. Adelman ◽  
J. J. West
Keyword(s):  
Air Quality ◽  
Tropospheric Ozone ◽  
Radiative Forcing ◽  
Transport Model ◽  
Surface Ozone ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Chemical Transport Model ◽  
Large Variability ◽  
Volatile Organic

Abstract. Non-methane volatile organic compounds (NMVOCs) influence air quality and global climate change through their effects on secondary air pollutants and climate forcers. Here we simulate the air quality and radiative forcing (RF) impacts of changes in ozone, methane, and sulfate from halving anthropogenic NMVOC emissions globally and from 10 regions individually, using a global chemical transport model and a standalone radiative transfer model. Halving global NMVOC emissions decreases global annual average tropospheric methane and ozone by 36.6 ppbv and 3.3 Tg, respectively, and surface ozone by 0.67 ppbv. All regional reductions slow the production of peroxyacetyl nitrate (PAN), resulting in regional to intercontinental PAN decreases and regional NOx increases. These NOx increases drive tropospheric ozone increases nearby or downwind of source regions in the Southern Hemisphere (South America, Southeast Asia, Africa, and Australia). Some regions' NMVOC emissions contribute importantly to air pollution in other regions, such as East Asia, the Middle East, and Europe, whose impact on US surface ozone is 43%, 34%, and 34% of North America's impact. Global and regional NMVOC reductions produce widespread negative net RFs (cooling) across both hemispheres from tropospheric ozone and methane decreases, and regional warming and cooling from changes in tropospheric ozone and sulfate (via several oxidation pathways). The 100 yr and 20 yr global warming potentials (GWP100, GWP20) are 2.36 and 5.83 for the global reduction, and 0.079 to 6.05 and −1.13 to 18.9 among the 10 regions. The NMVOC RF and GWP estimates are generally lower than previously modeled estimates, due to the greater NMVOC/NOx emissions ratios simulated, which result in less sensitivity to NMVOC emissions changes and smaller global O3 burden responses, in addition to differences in the representation of NMVOCs and oxidation chemistry among models. Accounting for a fuller set of RF contributions may change the relative magnitude of each region's impacts. The large variability in the RF and GWP of NMVOCs among regions suggest that regionally specific metrics may be necessary to include NMVOCs in multi-gas climate trading schemes.

scholarly journals Contrasting the direct radiative effect and direct radiative forcing of aerosols

2014 ◽  
Vol 14 (11) ◽  
pp. 5513-5527 ◽  
Author(s):  
C. L. Heald ◽  
D. A. Ridley ◽  
J. H. Kroll ◽  
S. R. H. Barrett ◽  
K. E. Cady-Pereira ◽  
...  
Keyword(s):  
Energy Balance ◽  
Radiative Forcing ◽  
Transport Model ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Radiative Effect ◽  
Chemical Transport Model ◽  
Anthropogenic Aerosols ◽  
Anthropogenic Aerosol ◽  
Direct Radiative Forcing

Abstract. The direct radiative effect (DRE) of aerosols, which is the instantaneous radiative impact of all atmospheric particles on the Earth's energy balance, is sometimes confused with the direct radiative forcing (DRF), which is the change in DRE from pre-industrial to present-day (not including climate feedbacks). In this study we couple a global chemical transport model (GEOS-Chem) with a radiative transfer model (RRTMG) to contrast these concepts. We estimate a global mean all-sky aerosol DRF of −0.36 Wm−2 and a DRE of −1.83 Wm−2 for 2010. Therefore, natural sources of aerosol (here including fire) affect the global energy balance over four times more than do present-day anthropogenic aerosols. If global anthropogenic emissions of aerosols and their precursors continue to decline as projected in recent scenarios due to effective pollution emission controls, the DRF will shrink (−0.22 Wm−2 for 2100). Secondary metrics, like DRE, that quantify temporal changes in both natural and anthropogenic aerosol burdens are therefore needed to quantify the total effect of aerosols on climate.

scholarly journals Net radiative forcing and air quality responses to regional CO emission reductions

2012 ◽  
Vol 12 (12) ◽  
pp. 33443-33488
Author(s):  
M. M. Fry ◽  
M. D. Schwarzkopf ◽  
Z. Adelman ◽  
V. Naik ◽  
W. J. Collins ◽  
...  
Keyword(s):  
Air Quality ◽  
Radiative Forcing ◽  
Transport Model ◽  
Surface Ozone ◽  
Ozone Production ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
International Climate Agreements ◽  
The Tropics ◽  
Reduction Region

Abstract. Carbon monoxide (CO) emissions influence global and regional air quality and global climate change by affecting atmospheric oxidants and secondary species. We simulate the influence of halving anthropogenic CO emissions globally and individually from 10 regions on surface and tropospheric ozone, methane, and aerosol concentrations using a global chemical transport model (MOZART-4 for the year 2005). Net radiative forcing (RF) is then estimated using the GFDL standalone radiative transfer model. We estimate that halving global CO emissions decreases global annual average concentrations of surface ozone by 0.45 ppbv, tropospheric methane by 73 ppbv, and global annual net RF by 36.1 mW m−2, nearly equal to the sum of changes from the 10 regional reductions. Global annual net RF per unit change in emissions and the 100-yr global warming potential (GWP100) are estimated as −0.124 mW m−2 (Tg CO yr−1)−1 and 1.34, respectively, for the global CO reduction, and ranging from −0.115 to −0.131 mW m−2 (Tg CO yr−1)−1 and 1.26 to 1.44 across 10 regions, with the greatest sensitivities for regions in the tropics. The net RF distributions show widespread cooling corresponding to the O3 and CH4 decreases, and localized positive and negative net RFs due to changes in aerosols. The strongest annual net RF impacts occur within the tropics (28° S–28° N) followed by the northern mid-latitudes (28° N–60° N), independent of reduction region, while the greatest changes in surface CO and ozone concentrations occur within the reduction region. Some regional reductions strongly influence the air quality in other regions, such as East Asia, which has an impact on US surface ozone that is 93% of that from North America. Changes in the transport of CO and downwind ozone production clearly exceed the direct export of ozone from each reduction region. The small variation in CO GWPs among world regions suggests that future international climate agreements could adopt a globally uniform metric for CO with little error, or could use different GWPs for each continent. Doing so may increase the incentive to reduce CO through coordinated policies addressing climate and air quality.

scholarly journals Interpreting the Ultraviolet Aerosol Index observed with the OMI satellite instrument to understand absorption by organic aerosols: implications for atmospheric oxidation and direct radiative effects

2015 ◽  
Vol 15 (19) ◽  
pp. 27405-27447
Author(s):  
M. S. Hammer ◽  
R. V. Martin ◽  
A. van Donkelaar ◽  
V. Buchard ◽  
O. Torres ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
South America ◽  
Biomass Burning ◽  
Southern Africa ◽  
Radiative Forcing ◽  
Transport Model ◽  
Organic Aerosol ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Aerosol Index

Abstract. Satellite observations of the Ultraviolet Aerosol Index (UVAI) are sensitive to absorption of solar radiation by aerosols; this absorption affects photolysis frequencies and radiative forcing. We develop a global simulation of the UVAI using the 3-D chemical transport model GEOS-Chem coupled with the Vector Linearized Discrete Ordinate Radiative Transfer model (VLIDORT). The simulation is applied to interpret UVAI observations from the Ozone Monitoring Instrument (OMI) for the year 2007. Simulated and observed values are highly consistent in regions where mineral dust dominates the UVAI, but a large negative bias (−0.32 to −0.97) exists between simulated and observed values in biomass burning regions. We determine effective optical properties for absorbing organic aerosol, known as brown carbon (BrC), and implement them into GEOS-Chem to better represent observed UVAI values over biomass burning regions. The addition of absorbing BrC decreases the mean bias between simulated and OMI UVAI values from −0.57 to −0.09 over West Africa in January, from −0.32 to +0.0002 over South Asia in April, from −0.97 to −0.22 over southern Africa in July, and from −0.50 to +0.33 over South America in September. The spectral dependence of absorption after adding BrC to the model is broadly consistent with reported observations for biomass burning aerosol, with Absorbing Angstrom Exponent (AAE) values ranging from 2.9 in the ultraviolet (UV) to 1.3 across the UV-Near IR spectrum. We assess the effect of the additional UV absorption by BrC on atmospheric photochemistry by examining tropospheric hydroxyl radical (OH) concentrations in GEOS-Chem. The inclusion of BrC decreases OH by up to 35 % over South America in September, up to 25 % over southern Africa in July, and up to 20 % over other biomass burning regions. Global annual mean OH concentrations in GEOS-Chem decrease due to the presence of absorbing BrC, increasing the methyl chloroform lifetime from 5.62 to 5.68 years, thus reducing the bias against observed values. We calculate the direct radiative effect (DRE) of BrC using GEOS-Chem coupled with the radiative transfer model RRTMG (GC-RT). Treating organic aerosol as containing absorbing BrC rather than as primarily scattering changes global annual mean all-sky top of atmosphere (TOA) DRE by +0.05 W m-2 and all-sky surface DRE by −0.06 W m-2. Regional changes of up to +0.5 W m-2 at TOA and down to −1 W m-2 at the surface are found over major biomass burning regions.

scholarly journals On the uses of a new linear scheme for stratospheric methane in global models: water source, transport tracer and radiative forcing

2012 ◽  
Vol 12 (1) ◽  
pp. 479-523 ◽  
Author(s):  
B. M. Monge-Sanz ◽  
M. P. Chipperfield ◽  
A. Untch ◽  
J.-J. Morcrette ◽  
A. Rap ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
General Circulation ◽  
Transport Model ◽  
Circulation Model ◽  
Water Source ◽  
Reanalysis Data ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Ecmwf Model ◽  
The Impact

Abstract. A new linear parameterisation for stratospheric methane (CoMeCAT) has been developed and tested. The scheme is derived from a 3-D full chemistry transport model (CTM) and tested within the same chemistry model itself, as well as in an independent general circulation model (GCM). The new CH4/H2O scheme is suitable for any global model and here is shown to provide realistic profiles in the 3-D TOMCAT/SLIMCAT CTM and in the ECMWF (European Centre for Medium-Range Weather Forecasts) GCM. Simulation results from the new stratospheric scheme are in good agreement with the full-chemistry CTM CH4 field and with observations from the Halogen Occultation Experiment (HALOE). The CH4 scheme has also been used to derive a source for stratospheric water. Stratospheric water increments obtained in this way within the CTM produce vertical and latitudinal H2O variation in fair agreement with satellite observations. Stratospheric H2O distributions in the ECMWF GCM present realistic overall features although concentrations are lower than in the CTM run (up to 0.5 ppmv lower above 10 hPa). The potential of the new CoMeCAT scheme for evaluating long-term transport within the ECMWF model is exploited to assess the impacts of nudging the free running GCM to ERA-40 and ERA-Interim reanalyses. In this case, the nudged GCM shows similar transport patterns to the CTM forced by the corresponding reanalysis data, ERA-Interim producing better results than ERA-40. The impact that the new methane description has in the GCM radiation scheme is also explored. Compared to the default CH4 climatology used by the ECMWF model, CoMeCAT produces up to 2 K cooling in the tropical lower stratosphere. The effect of using the CoMeCAT scheme for radiative forcing (RF) calculations has been investigated using the off-line Edwards-Slingo (E-S) radiative transfer model. Compared to the use of a tropospheric global 3-D CH4 value, the CoMeCAT distributions produce an overall decrease in the annual mean net RF, with the largest decrease found over the Southern Hemisphere high latitudes. The effect of the new CH4 stratospheric distribution on these RF calculations is of up to 30 mW m−2, i.e. the same order of magnitude, and opposite sign, as the inclusion of aircraft contrails formation in the radiative model.

scholarly journals Interpreting the ultraviolet aerosol index observed with the OMI satellite instrument to understand absorption by organic aerosols: implications for atmospheric oxidation and direct radiative effects

2016 ◽  
Vol 16 (4) ◽  
pp. 2507-2523 ◽  
Author(s):  
Melanie S. Hammer ◽  
Randall V. Martin ◽  
Aaron van Donkelaar ◽  
Virginie Buchard ◽  
Omar Torres ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
South America ◽  
Biomass Burning ◽  
Southern Africa ◽  
Radiative Forcing ◽  
Transport Model ◽  
Organic Aerosol ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Aerosol Index

Abstract. Satellite observations of the ultraviolet aerosol index (UVAI) are sensitive to absorption of solar radiation by aerosols; this absorption affects photolysis frequencies and radiative forcing. We develop a global simulation of the UVAI using the 3-D chemical transport model GEOS-Chem coupled with the Vector Linearized Discrete Ordinate Radiative Transfer model (VLIDORT). The simulation is applied to interpret UVAI observations from the Ozone Monitoring Instrument (OMI) for the year 2007. Simulated and observed values are highly consistent in regions where mineral dust dominates the UVAI, but a large negative bias (−0.32 to −0.97) exists between simulated and observed values in biomass burning regions. We determine effective optical properties for absorbing organic aerosol, known as brown carbon (BrC), and implement them into GEOS-Chem to better represent observed UVAI values over biomass burning regions. The inclusion of absorbing BrC decreases the mean bias between simulated and OMI UVAI values from −0.57 to −0.09 over West Africa in January, from −0.32 to +0.0002 over South Asia in April, from −0.97 to −0.22 over southern Africa in July, and from −0.50 to +0.33 over South America in September. The spectral dependence of absorption after including BrC in the model is broadly consistent with reported observations for biomass burning aerosol, with absorbing Ångström exponent (AAE) values ranging from 2.9 in the ultraviolet (UV) to 1.3 across the UV–Near IR spectrum. We assess the effect of the additional UV absorption by BrC on atmospheric photochemistry by examining tropospheric hydroxyl radical (OH) concentrations in GEOS-Chem. The inclusion of BrC decreases OH by up to 30 % over South America in September, up to 20 % over southern Africa in July, and up to 15 % over other biomass burning regions. Global annual mean OH concentrations in GEOS-Chem decrease due to the presence of absorbing BrC, increasing the methyl chloroform lifetime from 5.62 to 5.68 years, thus reducing the bias against observed values. We calculate the direct radiative effect (DRE) of BrC using GEOS-Chem coupled with the radiative transfer model RRTMG (GC-RT). Treating organic aerosol as containing more strongly absorbing BrC changes the global annual mean all-sky top of atmosphere (TOA) DRE by +0.03 W m−2 and all-sky surface DRE by −0.08 W m−2. Regional changes of up to +0.3 W m−2 at TOA and down to −1.5 W m−2 at the surface are found over major biomass burning regions.

scholarly journals On the uses of a new linear scheme for stratospheric methane in global models: water source, transport tracer and radiative forcing

2013 ◽  
Vol 13 (18) ◽  
pp. 9641-9660 ◽  
Author(s):  
B. M. Monge-Sanz ◽  
M. P. Chipperfield ◽  
A. Untch ◽  
J.-J. Morcrette ◽  
A. Rap ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
General Circulation ◽  
Transport Model ◽  
Circulation Model ◽  
Water Source ◽  
Reanalysis Data ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Run Up ◽  
Transport Patterns

Abstract. This study evaluates effects and applications of a new linear parameterisation for stratospheric methane and water vapour. The new scheme (CoMeCAT) is derived from a 3-D full-chemistry-transport model (CTM). It is suitable for any global model, and is shown here to produce realistic profiles in the TOMCAT/SLIMCAT 3-D CTM and the ECMWF (European Centre for Medium-Range Weather Forecasts) general circulation model (GCM). Results from the new scheme are in good agreement with the full-chemistry CTM CH4 field and with observations from the Halogen Occultation Experiment (HALOE). The scheme is also used to derive stratospheric water increments, which in the CTM produce vertical and latitudinal H2O variations in fair agreement with satellite observations. Stratospheric H2O distributions in the ECMWF GCM show realistic overall features, although concentrations are smaller than in the CTM run (up to 0.5 ppmv smaller above 10 hPa). The potential of the new CoMeCAT tracer for evaluating stratospheric transport is exploited to assess the impacts of nudging the free-running GCM to ERA-40 and ERA-Interim reanalyses. The nudged GCM shows similar transport patterns to the offline CTM forced by the corresponding reanalysis data. The new scheme also impacts radiation and temperature in the model. Compared to the default CH4 climatology and H2O used by the ECMWF radiation scheme, the main effect on ECMWF temperatures when considering both CH4 and H2O from CoMeCAT is a decrease of up to 1.0 K over the tropical mid/low stratosphere. The effect of using the CoMeCAT scheme for radiative forcing (RF) calculations is investigated using the offline Edwards–Slingo radiative transfer model. Compared to the default model option of a tropospheric global 3-D CH4 value, the CoMeCAT distribution produces an overall change in the annual mean net RF of up to −30 mW m−2.

scholarly journals Beyond direct radiative forcing: the case for characterizing the direct radiative effect of aerosols

2013 ◽  
Vol 13 (12) ◽  
pp. 32925-32961 ◽  
Author(s):  
C. L. Heald ◽  
D. A. Ridley ◽  
J. H. Kroll ◽  
S. R. H. Barrett ◽  
K. E. Cady-Pereira ◽  
...  
Keyword(s):  
Energy Balance ◽  
Radiative Forcing ◽  
Transport Model ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Radiative Effect ◽  
Climate Feedbacks ◽  
Anthropogenic Aerosols ◽  
Anthropogenic Aerosol ◽  
Direct Radiative Forcing

Abstract. The direct radiative effect (DRE) of aerosols, which is the instantaneous radiative impact of all atmospheric particles on the Earth's energy balance, is often confused with the direct radiative forcing (DRF), which is the change in DRE from pre-industrial to present-day (not including climate feedbacks). We use here a coupled global chemical transport model (GEOS-Chem) and radiative transfer model (RRTMG) to contrast these concepts. We estimate a global mean all-sky aerosol DRF of −0.36 Wm−2 and a DRE of −1.83 Wm−2 for 2010. Therefore, natural sources of aerosol (here including fire) affect the global energy balance over four times more than do present-day anthropogenic aerosols. If global anthropogenic emissions of aerosols and their precursors continue to decline as projected in recent scenarios due to effective pollution emission controls, the DRF will shrink (−0.22 Wm−2 for 2100), while the climate feedbacks on aerosols under rising global temperatures will likely amplify. Secondary metrics, like DRE, that quantify temporal changes in both natural and anthropogenic aerosol burdens are therefore needed to quantify the total effect of aerosols on climate.

Sign in / Sign up

Export Citation Format

Share Document