Impact of Aviation on Climate: FAA’s Aviation Climate Change Research Initiative (ACCRI) Phase II

Abstract Under the Federal Aviation Administration’s (FAA) Aviation Climate Change Research Initiative (ACCRI), non-CO2 climatic impacts of commercial aviation are assessed for current (2006) and for future (2050) baseline and mitigation scenarios. The effects of the non-CO2 aircraft emissions are examined using a number of advanced climate and atmospheric chemistry transport models. Radiative forcing (RF) estimates for individual forcing effects are provided as a range for comparison against those published in the literature. Preliminary results for selected RF components for 2050 scenarios indicate that a 2% increase in fuel efficiency and a decrease in NOx emissions due to advanced aircraft technologies and operational procedures, as well as the introduction of renewable alternative fuels, will significantly decrease future aviation climate impacts. In particular, the use of renewable fuels will further decrease RF associated with sulfate aerosol and black carbon. While this focused ACCRI program effort has yielded significant new knowledge, fundamental uncertainties remain in our understanding of aviation climate impacts. These include several chemical and physical processes associated with NOx–O3–CH4 interactions and the formation of aviation-produced contrails and the effects of aviation soot aerosols on cirrus clouds as well as on deriving a measure of change in temperature from RF for aviation non-CO2 climate impacts—an important metric that informs decision-making.

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AerChemMIP: quantifying the effects of chemistry and aerosols in CMIP6

Geoscientific Model Development ◽

10.5194/gmd-10-585-2017 ◽

2017 ◽

Vol 10 (2) ◽

pp. 585-607 ◽

Cited By ~ 66

Author(s):

William J. Collins ◽

Jean-François Lamarque ◽

Michael Schulz ◽

Olivier Boucher ◽

Veronika Eyring ◽

...

Keyword(s):

Air Quality ◽

Atmospheric Chemistry ◽

Radiative Forcing ◽

Climate Models ◽

Coupled Model ◽

Climate Impacts ◽

Atmospheric Composition ◽

Historical Period ◽

Model Intercomparison ◽

Intercomparison Project

Abstract. The Aerosol Chemistry Model Intercomparison Project (AerChemMIP) is endorsed by the Coupled-Model Intercomparison Project 6 (CMIP6) and is designed to quantify the climate and air quality impacts of aerosols and chemically reactive gases. These are specifically near-term climate forcers (NTCFs: methane, tropospheric ozone and aerosols, and their precursors), nitrous oxide and ozone-depleting halocarbons. The aim of AerChemMIP is to answer four scientific questions. 1. How have anthropogenic emissions contributed to global radiative forcing and affected regional climate over the historical period? 2. How might future policies (on climate, air quality and land use) affect the abundances of NTCFs and their climate impacts? 3.How do uncertainties in historical NTCF emissions affect radiative forcing estimates? 4. How important are climate feedbacks to natural NTCF emissions, atmospheric composition, and radiative effects? These questions will be addressed through targeted simulations with CMIP6 climate models that include an interactive representation of tropospheric aerosols and atmospheric chemistry. These simulations build on the CMIP6 Diagnostic, Evaluation and Characterization of Klima (DECK) experiments, the CMIP6 historical simulations, and future projections performed elsewhere in CMIP6, allowing the contributions from aerosols and/or chemistry to be quantified. Specific diagnostics are requested as part of the CMIP6 data request to highlight the chemical composition of the atmosphere, to evaluate the performance of the models, and to understand differences in behaviour between them.

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AirClim: an efficient tool for climate evaluation of aircraft technology

Atmospheric Chemistry and Physics ◽

10.5194/acp-8-4621-2008 ◽

2008 ◽

Vol 8 (16) ◽

pp. 4621-4639 ◽

Cited By ~ 60

Author(s):

V. Grewe ◽

A. Stenke

Keyword(s):

Climate Change ◽

Water Vapour ◽

Radiative Forcing ◽

Climate Impacts ◽

Assessment Tools ◽

Surface Temperature Change ◽

Near Surface ◽

Temperature Changes ◽

Wide Range ◽

Concentration Changes

Abstract. Climate change is a challenge to society and to cope with requires assessment tools which are suitable to evaluate new technology options with respect to their impact on global climate. Here we present AirClim, a model which comprises a linearisation of atmospheric processes from the emission to radiative forcing, resulting in an estimate in near surface temperature change, which is presumed to be a reasonable indicator for climate change. The model is designed to be applicable to aircraft technology, i.e. the climate agents CO2, H2O, CH4 and O3 (latter two resulting from NOx-emissions) and contrails are taken into account. AirClim combines a number of precalculated atmospheric data with aircraft emission data to obtain the temporal evolution of atmospheric concentration changes, radiative forcing and temperature changes. These precalculated data are derived from 25 steady-state simulations for the year 2050 with the climate-chemistry model E39/C, prescribing normalised emissions of nitrogen oxides and water vapour at various atmospheric regions. The results show that strongest climate impacts (year 2100) from ozone changes occur for emissions in the tropical upper troposphere (60 mW/m2; 80 mK for 1 TgN/year emitted) and from methane changes from emissions in the middle tropical troposphere (−2.7% change in methane lifetime; –30 mK per TgN/year). For short-lived species (e.g. ozone, water vapour, methane) individual perturbation lifetimes are derived depending on the region of emission. A comparison of this linearisation approach with results from a comprehensive climate-chemistry model shows reasonable agreement with respect to concentration changes, radiative forcing, and temperature changes. For example, the total impact of a supersonic fleet on radiative forcing (mainly water vapour) is reproduced within 10%. A wide range of application is demonstrated.

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Integrated Assessment Models (IAMs) for Climate Change

Environmental Science ◽

10.1093/obo/9780199363445-0043 ◽

2016 ◽

Cited By ~ 3

Author(s):

Zili Yang ◽

Yi-Ming Wei ◽

Zhifu Mi

Keyword(s):

Climate Change ◽

Interdisciplinary Research ◽

Integrated Assessment ◽

Social Economic ◽

Methodological Approach ◽

Integrated Model ◽

Climate Impacts ◽

Research Approach ◽

Climate Change Research ◽

Integrated Assessment Models

Integrated assessment models (IAMs) for climate change refers to a broad category of research approaches in climate change. Climate change is the most complicated global environmental problem. By the very nature of climate change, research has to be interdisciplinary and multifaceted. IAM is the mainstream methodological approach in climate change research. Most researchers in climate change utilize IAMs directly or indirectly. IAMs draw knowledge and strengths from various disciplines related to climate change; contributions from each discipline rely on the mathematical representations of certain relationships connected to climate change; disciplinary components are linked through a unified modeling platform(s). In particular, IAMs for climate change usually involve social-economic components as well as natural sciences components. The key linkages in IAM platforms are anthropogenic greenhouse gas (GHG) emissions in climate systems and climate change impacts on social-economic systems. The outputs of IAMs are numerical simulation results based on assumptions, historical data, and scenario designs. IAMs are widely used in assessing various GHG mitigation policies and climate impacts. In fact, conclusions in the Intergovernmental Panel on Climate Change (IPCC) Assessment Reports are drawn substantially from numerous IAMs. IAMs for climate change started in the late 1980s. Since then, IAMs for climate change have developed into a full-fledged interdisciplinary research field that involves hundreds of models, thriving online resources, and thousands of academic publications and policy reports around the world. IAM for climate change, as an interdisciplinary research approach, has received recognition by mainstream disciplines. The Dynamic Integrated model of Climate and the Economy (DICE) and the Regional Integrated model of Climate and the Economy (RICE)—two IAMs for climate change—are part of the core contributions in William Nordhaus’s Nobel Prize in Economic Sciences in 2018.

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Inter-disciplinary, multi-scale science to support society to adapt under global change

Marine and Freshwater Research ◽

10.1071/mf18355 ◽

2019 ◽

Vol 70 (1) ◽

pp. 1

Author(s):

Karlie S. McDonald ◽

Alistair J. Hobday ◽

Juan Diego Gaitán-Espitia

Keyword(s):

Climate Change ◽

Scientific Community ◽

Climate Impacts ◽

System Structure ◽

Research Front ◽

Climate Change Research ◽

Multi Scale ◽

Mitigation And Adaptation ◽

Marine System ◽

The Media

Factualised storytelling narratives may assist scientists to communicate inter-disciplinary, multi-scale climate change research with stakeholders and non-expert members of the community. Scientists are increasingly required to balance scientific rigour with storytelling narratives that can facilitate climate change mitigation and adaptation as new communication technologies evolve. In this editorial to the research front, ‘Climate impacts on marine system structure and function: molecules to ecosystems’, a review of climate change coverage in the media since 1980 showed that climate change science had a substantial voice globally and, in particular, in countries with carbon-dependent economies. However, the effective communication of multi-scale climate change research in the media can be complicated by the complex messages, the lack of training scientists receive in communication, and the traditionally distant relationship that the scientific community has with the media and, more so, with the broader community. Considerable scientific effort is being made to overcome these challenges as additional responsibility is placed on the scientific community to produce newsworthy scientific outputs. However, the integration of inter-disciplinary, multi-scale information, such as outlined in this research front, can result in more holistic climate change stories that scientists can effectively communicate with stakeholders and the broader community.

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Integrated approaches to climate–crop modelling: needs and challenges

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2005.1739 ◽

2005 ◽

Vol 360 (1463) ◽

pp. 2049-2065 ◽

Cited By ~ 46

Author(s):

Richard A. Betts

Keyword(s):

Climate Change ◽

Atmospheric Chemistry ◽

Land Surface ◽

Radiative Forcing ◽

Crop Production ◽

Large Scale ◽

Climate Models ◽

Atmospheric Composition ◽

Short Time Scale ◽

Crop Models

This paper discusses the need for a more integrated approach to modelling changes in climate and crops, and some of the challenges posed by this. While changes in atmospheric composition are expected to exert an increasing radiative forcing of climate change leading to further warming of global mean temperatures and shifts in precipitation patterns, these are not the only climatic processes which may influence crop production. Changes in the physical characteristics of the land cover may also affect climate; these may arise directly from land use activities and may also result from the large-scale responses of crops to seasonal, interannual and decadal changes in the atmospheric state. Climate models used to drive crop models may, therefore, need to consider changes in the land surface, either as imposed boundary conditions or as feedbacks from an interactive climate–vegetation model. Crops may also respond directly to changes in atmospheric composition, such as the concentrations of carbon dioxide (CO 2 ), ozone (O 3 ) and compounds of sulphur and nitrogen, so crop models should consider these processes as well as climate change. Changes in these, and the responses of the crops, may be intimately linked with meteorological processes so crop and climate models should consider synergies between climate and atmospheric chemistry. Some crop responses may occur at scales too small to significantly influence meteorology, so may not need to be included as feedbacks within climate models. However, the volume of data required to drive the appropriate crop models may be very large, especially if short-time-scale variability is important. Implementation of crop models within climate models would minimize the need to transfer large quantities of data between separate modelling systems. It should also be noted that crop responses to climate change may interact with other impacts of climate change, such as hydrological changes. For example, the availability of water for irrigation may be affected by changes in runoff as a direct consequence of climate change, and may also be affected by climate-related changes in demand for water for other uses. It is, therefore, necessary to consider the interactions between the responses of several impacts sectors to climate change. Overall, there is a strong case for a much closer coupling between models of climate, crops and hydrology, but this in itself poses challenges arising from issues of scale and errors in the models. A strategy is proposed whereby the pursuit of a fully coupled climate–chemistry–crop–hydrology model is paralleled by continued use of separate climate and land surface models but with a focus on consistency between the models.

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AerChemMIP: Quantifying the effects of chemistry and aerosols in CMIP6

10.5194/gmd-2016-139 ◽

2016 ◽

Cited By ~ 7

Author(s):

William J. Collins ◽

Jean-François Lamarque ◽

Michael Schulz ◽

Olivier Boucher ◽

Veronika Eyring ◽

...

Keyword(s):

Air Quality ◽

Atmospheric Chemistry ◽

Radiative Forcing ◽

Climate Models ◽

Coupled Model ◽

Climate Impacts ◽

Anthropogenic Emissions ◽

Historical Period ◽

Model Intercomparison ◽

Intercomparison Project

Abstract. The Aerosol Chemistry Model Intercomparison Project (AerChemMIP) is endorsed by the Coupled-Model Intercomparison Project 6 (CMIP6) and is designed to quantify the climate and air quality impacts of aerosols and chemically-reactive gases. These are specifically near-term climate forcers (NTCFs: tropospheric ozone and aerosols, and their precursors), methane, nitrous oxide and ozone-depleting halocarbons. The aim of AerChemMIP is to answer four scientific questions: 1. How have anthropogenic emissions contributed to global radiative forcing and affected regional climate over the historical period? 2. How will future policies (on climate, air quality and land use) affect these species and their climate impacts? 3. Can the uncertainties associated with anthropogenic emissions be quantified? 4. Can climate feedbacks occurring through changes in natural emissions be quantified? These questions will be addressed through targeted simulations with CMIP6 climate models that include an interactive representation of tropospheric aerosols and atmospheric chemistry. These simulations build on the CMIP6 Diagnostic, Evaluation and Characterization of Klima (DECK) experiments, the CMIP6 historical simulations, and future projections performed elsewhere in CMIP6, allowing the contributions from aerosols and chemistry to be quantified. Specific diagnostics are requested as part of the CMIP6 data request to evaluate the performance of the models, and to understand any differences in behaviour between them.

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The engineering options for mitigating the climate impacts of aviation

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2007.0012 ◽

2007 ◽

Vol 365 (1861) ◽

pp. 3047-3059 ◽

Cited By ~ 10

Author(s):

Victoria Williams

Keyword(s):

Climate Change ◽

Control Systems ◽

Traffic Control ◽

Environmental Performance ◽

Fuel Efficiency ◽

Air Traffic ◽

Climate Impacts ◽

Traffic System ◽

Reduce Carbon Dioxide

Aviation is a growing contributor to climate change, with unique impacts due to the altitude of emissions. If existing traffic growth rates continue, radical engineering solutions will be required to prevent aviation becoming one of the dominant contributors to climate change. This paper reviews the engineering options for mitigating the climate impacts of aviation using aircraft and airspace technologies. These options include not only improvements in fuel efficiency, which would reduce carbon dioxide (CO 2 ) emissions, but also measures to reduce non-CO 2 impacts including the formation of persistent contrails. Integrated solutions to optimize environmental performance will require changes to airframes, engines, avionics, air traffic control systems and airspace design. While market-based measures, such as offset schemes and emissions trading, receive growing attention, this paper sets out the crucial role of engineering in the challenge to develop a ‘green air traffic system’.

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Greenhouse Gas Policy Influences Climate via Direct Effects of Land-Use Change

Journal of Climate ◽

10.1175/jcli-d-12-00377.1 ◽

2013 ◽

Vol 26 (11) ◽

pp. 3657-3670 ◽

Cited By ~ 50

Author(s):

Andrew D. Jones ◽

William D. Collins ◽

James Edmonds ◽

Margaret S. Torn ◽

Anthony Janetos ◽

...

Keyword(s):

Climate Change ◽

Land Use ◽

Land Use Change ◽

Radiative Forcing ◽

Climate Impacts ◽

Earth System Model ◽

Assessment Model ◽

System Model ◽

Earth System ◽

Alternative Scenario

Abstract Proposed climate mitigation measures do not account for direct biophysical climate impacts of land-use change (LUC), nor do the stabilization targets modeled for phase 5 of the Coupled Model Intercomparison Project (CMIP5) representative concentration pathways (RCPs). To examine the significance of such effects on global and regional patterns of climate change, a baseline and an alternative scenario of future anthropogenic activity are simulated within the Integrated Earth System Model, which couples the Global Change Assessment Model, Global Land-Use Model, and Community Earth System Model. The alternative scenario has high biofuel utilization and approximately 50% less global forest cover than the baseline, standard RCP4.5 scenario. Both scenarios stabilize radiative forcing from atmospheric constituents at 4.5 W m−2 by 2100. Thus, differences between their climate predictions quantify the biophysical effects of LUC. Offline radiative transfer and land model simulations are also utilized to identify forcing and feedback mechanisms driving the coupled response. Boreal deforestation is found to strongly influence climate because of increased albedo coupled with a regional-scale water vapor feedback. Globally, the alternative scenario yields a twenty-first-century warming trend that is 0.5°C cooler than baseline, driven by a 1 W m−2 mean decrease in radiative forcing that is distributed unevenly around the globe. Some regions are cooler in the alternative scenario than in 2005. These results demonstrate that neither climate change nor actual radiative forcing is uniquely related to atmospheric forcing targets such as those found in the RCPs but rather depend on particulars of the socioeconomic pathways followed to meet each target.

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Impact of climate change on volcanic processes: current understanding and future challenges

10.31223/x58s5q ◽

2021 ◽

Author(s):

Thomas Aubry ◽

Jamie Farquharson ◽

Colin Rowell ◽

Sebastian Watt ◽

Virginie Pinel ◽

...

Keyword(s):

Climate Change ◽

Radiative Forcing ◽

Climate Changes ◽

Numerical Models ◽

Anthropogenic Activities ◽

Volcanic Eruptions ◽

Climate Impacts ◽

Volcanic Plume ◽

Atmospheric Conditions ◽

Climate Conditions

The impacts of volcanic eruptions on climate are increasingly well understood, but the mirror question of how climate changes affect volcanic systems and processes, which we term “climate-volcano impacts”, remains understudied. Accelerating research on this topic is critical in view of rapid climate change driven by anthropogenic activities. Over the last two decades, we have improved our understanding of how mass distribution on the Earth’s surface, in particular changes in ice and water distribution linked to glacial cycles, affects mantle melting, crustal magmatic processing and eruption rates. New hypotheses on the impacts of climate change on eruption processes have also emerged, including how eruption style and volcanic plume rise are affected by changing surface and atmospheric conditions, and how volcanic sulfate aerosol lifecycle, radiative forcing and climate impacts are modulated by background climate conditions. Future improvements in past climate reconstructions and current climate observations, volcanic eruption records and volcano monitoring, and numerical models will contribute to boost research on climate-volcano impacts. Important mechanisms remain to be explored, such as how changes in atmospheric circulation and precipitation will affect the volcanic ash lifecycle. Fostering a holistic and interdisciplinary approach to climate-volcano impacts is critical to gain a full picture of how ongoing climate changes may affect the environmental and societal impacts of volcanic activity.

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A strategy for climate evaluation of aircraft technology: an efficient climate impact assessment tool – AirClim

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-7-12185-2007 ◽

2007 ◽

Vol 7 (4) ◽

pp. 12185-12229 ◽

Cited By ~ 4

Author(s):

V. Grewe ◽

A. Stenke

Keyword(s):

Climate Change ◽

Radiative Forcing ◽

Climate Impact ◽

Climate Impacts ◽

Assessment Tools ◽

Nox Emissions ◽

Near Surface ◽

Temperature Changes ◽

Concentration Changes ◽

The Impact

Abstract. Climate change is a challenge to society and to cope with requires assessment tools which are suitable to evaluate new technology options with respect to their impact on climate. Here we present AirClim, a model which comprises a linearisation of the processes occurring from the emission to an estimate in near surface temperature change, which is presumed to be a reasonable indicator for climate change. The model is designed to be applicable to aircraft technology, i.e.~the climate agents CO2, H2O, CH4 and O3 (latter two resulting from NOx-emissions) and contrails are taken into account. It employs a number of precalculated atmospheric data and combines them with aircraft emission data to obtain the temporal evolution of atmospheric concentration changes, radiative forcing and temperature changes. The linearisation is based on precalculated data derived from 25 steady-state simulations of the state-of-the-art climate-chemistry model E39/C, which include sustained normalised emissions at various atmospheric regions. The results show that strongest climate impacts from ozone changes occur for emissions in the tropical upper troposphere (60 mW/m²; 80 mK for 1 TgN emitted), whereas from methane in the middle tropical troposphere (–2.7% change in methane lifetime; –30 mK per TgN). The estimate of the temperature changes caused by the individual climate agents takes into account a perturbation lifetime, related to the region of emission. A comparison of this approach with results from the TRADEOFF and SCENIC projects shows reasonable agreement with respect to concentration changes, radiative forcing, and temperature changes. The total impact of a supersonic fleet on radiative forcing (mainly water vapour) is reproduced within 5%. For subsonic air traffic (sustained emissions after 2050) results show that although ozone-radiative forcing is much less important than that from CO2 for the year 2100. However the impact on temperature is of comparable size even when taking into account temperature decreases from CH4. That implies that all future measures for climate stabilisation should concentrate on both CO2 and NOx emissions. A direct comparison of super- with subsonic aircraft (250 passengers, 5400 nm) reveals a 5 times higher climate impact of supersonics.

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