scholarly journals Emission metrics for quantifying regional climate impacts of aviation

2017 ◽  
Author(s):  
Marianne T. Lund ◽  
Borgar Aamaas ◽  
Terje Berntsen ◽  
Lisa Bock ◽  
Ulrike Burkhardt ◽  
...  
Keyword(s):  
North America ◽  
Temperature Change ◽  
Radiative Forcing ◽  
Large Scale ◽  
Regional Climate ◽  
Temperature Response ◽  
Climate Impacts ◽  
Pulse Emission ◽  
Source Regions ◽  
Regional Temperature

Abstract. This study examines the impacts of emissions from aviation in six source regions on global and regional temperature. We consider the NOx-induced impacts on ozone and methane, aerosols and contrail-cirrus formation, and calculate the global and regional climate metrics Global Warming Potential (GWP), Global Temperature change Potential (GTP) and Absolute Regional Temperature change Potential (ARTP). GWPs and GTPs vary by a factor 2–4 between source regions. We find the highest aviation aerosol metric values for South Asian emissions, while contrail-cirrus metrics are higher for Europe and North America, where contrail formation is prevalent, and South America plus Africa, where the optical depth is large once contrails form. The ARTP illustrate important differences in the latitudinal patterns of radiative forcing (RF) and temperature response: The temperature response in a given latitude band can be considerably stronger than suggested by the RF in that band, also emphasizing the importance of large-scale circulation impacts. To place our metrics in context, we quantify the temperature response in the four broad latitude bands following a one-year pulse emission from present-day aviation, including CO2. Aviation over North America and Europe cause the largest net warming impact in all latitude bands, reflecting the higher air traffic activity here. For all regions, the largest single warming contribution is from contrail-cirrus 20 years after the emissions, while CO2 becomes dominant at 100 years, although contrail-cirrus remain important in several regions also on this time scale. Our emission metrics can be further used to estimate regional temperature impact under alternative aviation emission scenarios. A first evaluation of the ARTP in the context of aviation suggests that further work to account for vertical sensitivities in the relationship between RF and temperature response would be valuable for further use of the concept.

scholarly journals Emission metrics for quantifying regional climate impacts of aviation

2017 ◽  
Vol 8 (3) ◽  
pp. 547-563 ◽  
Author(s):  
Marianne T. Lund ◽  
Borgar Aamaas ◽  
Terje Berntsen ◽  
Lisa Bock ◽  
Ulrike Burkhardt ◽  
...  
Keyword(s):  
North America ◽  
Temperature Change ◽  
Radiative Forcing ◽  
Large Scale ◽  
Regional Climate ◽  
Temperature Response ◽  
Climate Impacts ◽  
Source Regions ◽  
Latitudinal Patterns ◽  
Regional Temperature

Abstract. This study examines the impacts of emissions from aviation in six source regions on global and regional temperatures. We consider the NOx-induced impacts on ozone and methane, aerosols and contrail-cirrus formation and calculate the global and regional emission metrics global warming potential (GWP), global temperature change potential (GTP) and absolute regional temperature change potential (ARTP). The GWPs and GTPs vary by a factor of 2–4 between source regions. We find the highest aviation aerosol metric values for South Asian emissions, while contrail-cirrus metrics are higher for Europe and North America, where contrail formation is prevalent, and South America plus Africa, where the optical depth is large once contrails form. The ARTP illustrate important differences in the latitudinal patterns of radiative forcing (RF) and temperature response: the temperature response in a given latitude band can be considerably stronger than suggested by the RF in that band, also emphasizing the importance of large-scale circulation impacts. To place our metrics in context, we quantify temperature change in four broad latitude bands following 1 year of emissions from present-day aviation, including CO2. Aviation over North America and Europe causes the largest net warming impact in all latitude bands, reflecting the higher air traffic activity in these regions. Contrail cirrus gives the largest warming contribution in the short term, but remain important at about 15 % of the CO2 impact in several regions even after 100 years. Our results also illustrate both the short- and long-term impacts of CO2: while CO2 becomes dominant on longer timescales, it also gives a notable warming contribution already 20 years after the emission. Our emission metrics can be further used to estimate regional temperature change under alternative aviation emission scenarios. A first evaluation of the ARTP in the context of aviation suggests that further work to account for vertical sensitivities in the relationship between RF and temperature response would be valuable for further use of the concept.

scholarly journals Surface temperature response to regional Black Carbon emissions: Do location and magnitude matter?

2019 ◽  
Author(s):  
Maria Sand ◽  
Terje K. Berntsen ◽  
Annica Ekman ◽  
Hans-Christen Hansson ◽  
Anna Lewinschal
Keyword(s):  
North America ◽  
Surface Temperature ◽  
South Asia ◽  
Black Carbon ◽  
Temperature Change ◽  
Radiative Forcing ◽  
Sea Surface ◽  
Emission Region ◽  
Regional Temperature ◽  
Fully Coupled

Abstract. Aerosol radiative forcing can influence climate both locally and far outside the emission region. Here we investigate Black Carbon (BC) aerosols emitted in four major emissions areas and evaluate the importance of emission location and magnitude, as well as the concept of the absolute regional temperature-change potentials. We perform simulations with a climate model (NorESM) with a fully coupled ocean and with fixed sea surface temperatures. BC emissions are increased by a rate of 10 and 20 in South Asia, North America and Europe, respectively, and by 5 and 10 in East Asia (due to higher emissions there). We find strikingly similar regional surface temperature responses and geographical patterns per unit BC emission in Europe and North America, but somewhat lower temperature sensitivities for East Asian emissions. BC emitted in South Asia shows a different geographical pattern by changing the Indian monsoon and cooling the surface. Choosing the highest emission rate results in lower surface temperature change per emission unit compared to the lowest rate, but the difference is generally not statistically significant except for the Arctic. An advantage of high-perturbation simulations is the clearer emergence of regional signals. Our results show that the linearity of normalized temperature effects of BC is fairly well preserved despite the relatively large perturbations, but that regional temperature coefficients calculated from high perturbations may be a conservative estimate. Regardless of emission region, BC causes a northward shift of the ITCZ, and this shift is apparent both with fully coupled ocean and with fixed sea surface temperatures. For these regional BC emissions perturbations, we find that the effective radiative forcing is not a good measure of the climate response.

scholarly journals Regional temperature change potentials for short-lived climate forcers based on radiative forcing from multiple models

2017 ◽  
Vol 17 (17) ◽  
pp. 10795-10809 ◽  
Author(s):  
Borgar Aamaas ◽  
Terje K. Berntsen ◽  
Jan S. Fuglestvedt ◽  
Keith P. Shine ◽  
William J. Collins
Keyword(s):  
East Asia ◽  
Temperature Change ◽  
Northern Hemisphere ◽  
Radiative Forcing ◽  
Atmospheric Transport ◽  
Winter Season ◽  
Temperature Response ◽  
The Arctic ◽  
Regional Temperature ◽  
Hemisphere Winter

Abstract. We calculate the absolute regional temperature change potential (ARTP) of various short-lived climate forcers (SLCFs) based on detailed radiative forcing (RF) calculations from four different models. The temperature response has been estimated for four latitude bands (90–28° S, 28° S–28° N, 28–60° N, and 60–90° N). The regional pattern in climate response not only depends on the relationship between RF and surface temperature, but also on where and when emissions occurred and atmospheric transport, chemistry, interaction with clouds, and deposition. We present four emissions cases covering Europe, East Asia, the global shipping sector, and the entire globe. Our study is the first to estimate ARTP values for emissions during Northern Hemisphere summer (May–October) and winter season (November–April). The species studied are aerosols and aerosol precursors (black carbon, organic carbon, SO2, NH3), ozone precursors (NOx, CO, volatile organic compound), and methane (CH4). For the response to BC in the Arctic, we take into account the vertical structure of the RF in the atmosphere, and an enhanced climate efficacy for BC deposition on snow. Of all SLCFs, BC is the most sensitive to where and when the emissions occur, as well as giving the largest difference in response between the latitude bands. The temperature response in the Arctic per unit BC emission is almost four times larger and more than two times larger than the global average for Northern Hemisphere winter emissions for Europe and East Asia, respectively. The latitudinal breakdown likely gives a better estimate of the global temperature response as it accounts for varying efficacies with latitude. An annual pulse of non-methane SLCF emissions globally (representative of 2008) lead to a global cooling. In contrast, winter emissions in Europe and East Asia give a net warming in the Arctic due to significant warming from BC deposition on snow.

scholarly journals Evaluation of the absolute regional temperature potential

2012 ◽  
Vol 12 (17) ◽  
pp. 7955-7960 ◽  
Author(s):  
D. T. Shindell
Keyword(s):  
Radiative Forcing ◽  
Large Scale ◽  
Climate Models ◽  
Climate Model ◽  
Temperature Response ◽  
The Arctic ◽  
Large Set ◽  
Temperature Potential ◽  
Regional Temperature ◽  
The Absolute

Abstract. The Absolute Regional Temperature Potential (ARTP) is one of the few climate metrics that provides estimates of impacts at a sub-global scale. The ARTP presented here gives the time-dependent temperature response in four latitude bands (90–28° S, 28° S–28° N, 28–60° N and 60–90° N) as a function of emissions based on the forcing in those bands caused by the emissions. It is based on a large set of simulations performed with a single atmosphere-ocean climate model to derive regional forcing/response relationships. Here I evaluate the robustness of those relationships using the forcing/response portion of the ARTP to estimate regional temperature responses to the historic aerosol forcing in three independent climate models. These ARTP results are in good accord with the actual responses in those models. Nearly all ARTP estimates fall within ±20% of the actual responses, though there are some exceptions for 90–28° S and the Arctic, and in the latter the ARTP may vary with forcing agent. However, for the tropics and the Northern Hemisphere mid-latitudes in particular, the ±20% range appears to be roughly consistent with the 95% confidence interval. Land areas within these two bands respond 39–45% and 9–39% more than the latitude band as a whole. The ARTP, presented here in a slightly revised form, thus appears to provide a relatively robust estimate for the responses of large-scale latitude bands and land areas within those bands to inhomogeneous radiative forcing and thus potentially to emissions as well. Hence this metric could allow rapid evaluation of the effects of emissions policies at a finer scale than global metrics without requiring use of a full climate model.

scholarly journals Evaluation of the absolute regional temperature potential

2012 ◽  
Vol 12 (6) ◽  
pp. 13813-13825 ◽  
Author(s):  
D. T. Shindell
Keyword(s):  
Radiative Forcing ◽  
Large Scale ◽  
Climate Models ◽  
Climate Model ◽  
Temperature Response ◽  
Global Scale ◽  
Large Set ◽  
Temperature Potential ◽  
Regional Temperature ◽  
The Absolute

Abstract. The Absolute Regional Temperature Potential (ARTP) is one of the few climate metrics that provides estimates of impacts at a sub-global scale. The ARTP gives the time-dependent temperature response in four latitude bands (90–28° S, 28° S–28° N, 28–60° N and 60–90° N) as a function of the regional forcing imposed in those bands. It is based on a large set of simulations performed with a single atmosphere-ocean climate model. Here I evaluate ARTP estimates of regional temperature responses due to historic aerosol forcing in three independent climate models and show that the ARTP metric provides results in good accord with the actual responses in those models. Nearly all ARTP estimates fall within ±20% of the actual responses, and in particular for the tropics and the Northern Hemisphere mid-latitudes this range appears to be roughly consistent with the 95% confidence interval. Land areas within these two bands respond 41 ± 6% and 19 ± 28% more than the latitude band as a whole. The ARTP, presented here in a slightly revised form, thus appears to provide a relatively robust estimate for the responses of large-scale latitude bands and land areas within those bands to inhomogeneous radiative forcing.

scholarly journals Surface temperature response to regional black carbon emissions: do location and magnitude matter?

2020 ◽  
Vol 20 (5) ◽  
pp. 3079-3089 ◽  
Author(s):  
Maria Sand ◽  
Terje K. Berntsen ◽  
Annica M. L. Ekman ◽  
Hans-Christen Hansson ◽  
Anna Lewinschal
Keyword(s):  
North America ◽  
Surface Temperature ◽  
South Asia ◽  
Radiative Forcing ◽  
Temperature Response ◽  
Sea Surface ◽  
Emission Region ◽  
Surface Temperatures ◽  
Regional Temperature ◽  
Fully Coupled

Abstract. Aerosol radiative forcing can influence climate both locally and far outside the emission region. Here we investigate black carbon (BC) aerosols emitted in four major emission areas and evaluate the importance of emission location and magnitude as well as the concept of the absolute regional temperature-change potentials (ARTP). We perform simulations with a climate model (NorESM) with a fully coupled ocean and with fixed sea surface temperatures. BC emissions for year 2000 are increased by factors of 10 and 20 in South Asia, North America, and Europe, respectively, and by 5 and 10 in East Asia (due to higher emissions there). The perturbed simulations and a reference simulation are run for 100 years with three ensemble members each. We find strikingly similar regional surface temperature responses and geographical patterns per unit BC emission in Europe and North America but somewhat lower temperature sensitivities for East Asian emissions. BC emitted in South Asia shows a different geographical pattern in surface temperatures, by changing the Indian monsoon and cooling the surface. We find that the ARTP approach rather accurately reproduces the fully coupled temperature response of NorESM. Choosing the highest emission rate results in lower surface temperature change per emission unit compared to the lowest rate, but the difference is generally not statistically significant except for the Arctic. An advantage of high-perturbation simulations is the clearer emergence of regional signals. Our results show that the linearity of normalized temperature effects of BC is fairly well preserved despite the relatively large perturbations but that regional temperature coefficients calculated from high perturbations may be a conservative estimate. Regardless of emission region, BC causes a northward shift of the ITCZ, and this shift is apparent both with a fully coupled ocean and with fixed sea surface temperatures. For these regional BC emission perturbations, we find that the effective radiative forcing is not a good measure of the climate response. A limitation of this study is the uncertainties in BC–cloud interactions and the amount of BC absorption, both of which are model dependent.

scholarly journals Regional temperature change potentials for short lived climate forcers from multiple models

2017 ◽  
Author(s):  
Borgar Aamaas ◽  
Terje K. Berntsen ◽  
Jan S. Fuglestvedt ◽  
Keith P. Shine ◽  
William J. Collins
Keyword(s):  
East Asia ◽  
Temperature Change ◽  
Northern Hemisphere ◽  
Radiative Forcing ◽  
Atmospheric Transport ◽  
Winter Season ◽  
Temperature Response ◽  
The Arctic ◽  
Regional Temperature ◽  
Hemisphere Winter

Abstract. We calculate the absolute regional temperature change potential (ARTP) of various short lived climate forcers (SLCFs) based on detailed radiative forcing (RF) calculations from four different models. The temperature response has been estimated for four latitude bands (90–28° S, 28° S–28° N, 28–60° N, and 60–90° N). The regional pattern in climate response not only depends on the relationship between RF and surface temperature, but also on where and when emissions occurred and atmospheric transport, chemistry, interaction with clouds, and deposition. We present four emissions cases covering Europe, East Asia, the global shipping sector, and the globe. Our study is the first to estimate ARTP values for emissions during Northern Hemisphere summer (May–October) and winter season (November–April). The species studied are aerosols and aerosol precursors (black carbon (BC), organic carbon (OC), SO2, NH3), ozone precursors (NOx, CO, volatile organic compound (VOC)), and methane (CH4). For the response to BC in the Arctic, we take into account the vertical structure of the RF in the atmosphere, and an enhanced climate efficacy for BC deposition on snow. Of all SLCFs, BC is the most sensitive to where and when the emissions occur, as well as giving the largest difference in response between the latitude bands. The temperature response in the Arctic is almost 4 times larger and more than 2 times larger than the global average for Northern Hemisphere winter emissions for Europe and East Asia, respectively. The latitudinal breakdown gives likely a better estimate of the global temperature response as it accounts for varying efficacies with latitude. An annual pulse of non-methane SLCFs emissions globally (representative of 2008) leads to a global cooling. Whereas, winter emissions in Europe and East Asia give a net warming in the Arctic due to significant warming from BC deposition on snow.

scholarly journals Climate engineering and the ocean: effects on biogeochemistry and primary production

2017 ◽  
Author(s):  
Siv K. Lauvset ◽  
Jerry Tjiputra ◽  
Helene Muri
Keyword(s):  
Primary Production ◽  
Radiative Forcing ◽  
Large Scale ◽  
Stratospheric Aerosol ◽  
Climate Impacts ◽  
Environmental Drivers ◽  
Earth System ◽  
Climate Engineering ◽  
Mean Sea Surface ◽  
Radiation Management

Abstract. Here we use an Earth System Model with interactive biogeochemistry to project future ocean biogeochemistry impacts from large-scale deployment of three different radiation management (RM) climate engineering (also known as geoengineering) methods: stratospheric aerosol injection (SAI), marine sky brightening (MSB), and cirrus cloud thinning (CCT). We apply RM such that the change in radiative forcing in the RCP8.5 emission scenario is reduced to the change in radiative forcing in the RCP4.5 scenario. The resulting global mean sea surface temperatures in the RM experiments are comparable to those in RCP4.5, but there are regional differences. The forcing from MSB, for example, is applied over the oceans, so the cooling of the ocean is in some regions stronger for this method of RM than for the others. Changes in ocean primary production are much more variable, but SAI and MSB give a global decrease comparable to RCP4.5 (~ 6 % in 2100 relative to 1971–2000), while CCT give a much smaller global decrease of ~ 3 %. The spatially inhomogeneous changes in ocean primary production are partly linked to how the different RM methods affect the drivers of primary production (incoming radiation, temperature, availability of nutrients, and phytoplankton) in the model. The results of this work underscores the complexity of climate impacts on primary production, and highlights that changes are driven by an integrated effect of multiple environmental drivers, which all change in different ways. These results stress the uncertain changes to ocean productivity in the future and advocates caution at any deliberate attempt for large-scale perturbation of the Earth system.

scholarly journals Simulation of dust aerosol and its regional feedbacks over East Asia using a regional climate model

2008 ◽  
Vol 8 (2) ◽  
pp. 4625-4667 ◽  
Author(s):  
D. F. Zhang ◽  
A. S. Zakey ◽  
X. J. Gao ◽  
F. Giorgi
Keyword(s):  
East Asia ◽  
Regional Climate Model ◽  
Radiative Forcing ◽  
Climate Model ◽  
Regional Climate ◽  
Surface Cooling ◽  
Near Surface ◽  
Dust Aerosols ◽  
Source Regions ◽  
Mass Load

Abstract. The ICTP regional climate model (RegCM3) coupled with a desert dust model is used to simulate the radiative forcing and related climate effects of dust aerosols over East Asia. Two sets of experiments encompassing the main dust producing months, February to May, for 10 years (1997–2006) are conducted and inter-compared, one without (Exp. 1) and one with (Exp. 2) the radiative effects of dust aerosols. The simulation results are evaluated against ground station and satellite data. The model captures the basic observed climatology over the area of interest. The spatial and temporal variations of near surface concentration, mass load, and emission of dust aerosols from the main source regions are reproduced by model, with the main model deficiency being an overestimate of dust amount over the source regions and underestimate downwind of these source areas. Both the top-of-the-atmosphere (TOA) and surface radiative fluxes are decreased by dust and this causes a surface cooling locally up to −1°C. The inclusion of dust radiative forcing leads to a reduction of dust emission in the East Asia source regions, which is mainly caused by an increase in local stability and a corresponding decrease in dust lifting. Our results indicate that dust effects should be included in the assessment of climate change over East Asia.

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