scholarly journals Observations of greenhouse gases as climate indicators

2021 ◽  
Vol 165 (1-2) ◽  
Author(s):  
Lori Bruhwiler ◽  
Sourish Basu ◽  
James H. Butler ◽  
Abhishek Chatterjee ◽  
Ed Dlugokencky ◽  
...  
Keyword(s):  
Greenhouse Gases ◽  
Radiative Forcing ◽  
Fossil Fuels ◽  
Atmospheric Composition ◽  
Climate Feedback ◽  
Climate Mitigation ◽  
Climate Assessment ◽  
Climate Indicators ◽  
National Climate Assessment

AbstractHumans have significantly altered the energy balance of the Earth’s climate system mainly not only by extracting and burning fossil fuels but also by altering the biosphere and using halocarbons. The 3rd US National Climate Assessment pointed to a need for a system of indicators of climate and global change based on long-term data that could be used to support assessments and this led to the development of the National Climate Indicators System (NCIS). Here we identify a representative set of key atmospheric indicators of changes in atmospheric radiative forcing due to greenhouse gases (GHGs), and we evaluate atmospheric composition measurements, including non-CO2 GHGs for use as climate change indicators in support of the US National Climate Assessment. GHG abundances and their changes over time can provide valuable information on the success of climate mitigation policies, as well as insights into possible carbon-climate feedback processes that may ultimately affect the success of those policies. To ensure that reliable information for assessing GHG emission changes can be provided on policy-relevant scales, expanded observational efforts are needed. Furthermore, the ability to detect trends resulting from changing emissions requires a commitment to supporting long-term observations. Long-term measurements of greenhouse gases, aerosols, and clouds and related climate indicators used with a dimming/brightening index could provide a foundation for quantifying forcing and its attribution and reducing error in existing indicators that do not account for complicated cloud processes.

scholarly journals Skill and independence weighting for multi-model assessments

2017 ◽  
Vol 10 (6) ◽  
pp. 2379-2395 ◽  
Author(s):  
Benjamin M. Sanderson ◽  
Michael Wehner ◽  
Reto Knutti
Keyword(s):  
Weather Extremes ◽  
Climate Assessment ◽  
Temperature And Precipitation ◽  
Weighted Means ◽  
Relevant Variables ◽  
National Climate Assessment ◽  
Two Parameters ◽  
Precipitation Changes ◽  
Model Weighting

Abstract. We present a weighting strategy for use with the CMIP5 multi-model archive in the fourth National Climate Assessment, which considers both skill in the climatological performance of models over North America as well as the inter-dependency of models arising from common parameterizations or tuning practices. The method exploits information relating to the climatological mean state of a number of projection-relevant variables as well as metrics representing long-term statistics of weather extremes. The weights, once computed can be used to simply compute weighted means and significance information from an ensemble containing multiple initial condition members from potentially co-dependent models of varying skill. Two parameters in the algorithm determine the degree to which model climatological skill and model uniqueness are rewarded; these parameters are explored and final values are defended for the assessment. The influence of model weighting on projected temperature and precipitation changes is found to be moderate, partly due to a compensating effect between model skill and uniqueness. However, more aggressive skill weighting and weighting by targeted metrics is found to have a more significant effect on inferred ensemble confidence in future patterns of change for a given projection.

The Environment and the Role of Gas

1993 ◽  
Vol 4 (2) ◽  
pp. 110-122
Author(s):  
Sylvie Cornot-Gandolphe
Keyword(s):  
Natural Gas ◽  
Greenhouse Gases ◽  
Fossil Fuels ◽  
Financial Constraints ◽  
Gas Production ◽  
Transport Costs ◽  
Consumer Markets ◽  
Emission Of Greenhouse Gases

The combustion of fossil fuels causes the emission of greenhouse gases such as C02, methane and NOx. The use of natural gas in place of oil and coal can help indeed to reduce greenhouse gases emission because natural gas is the cleanest of fossil fuels. Its non-pollutant character offers it extremely favourable prospects. World consumption is bound to increase rapidly, from 2120 Bern in 1991 to 3100-3500 Bern in 2010. Expanding world output will not raise any problems of resources because natural gas is an abundant energy source. However, gas production and transport costs are going to rise due to increasing distances between main gas reserves and consumer markets. The financial constraints will be the major factor limiting the growth in natural gas trade. And new solutions would have to be found in order to implement today the projects required in the long-term.

scholarly journals Twenty years of ground-based NDACC FTIR spectrometry at Izaña Observatory – overview and long-term comparison to other techniques

2021 ◽  
Vol 21 (20) ◽  
pp. 15519-15554
Author(s):  
Omaira E. García ◽  
Matthias Schneider ◽  
Eliezer Sepúlveda ◽  
Frank Hase ◽  
Thomas Blumenstock ◽  
...  
Keyword(s):  
Climate Models ◽  
Measurement Techniques ◽  
Temporal Stability ◽  
Carbonyl Sulfide ◽  
Quality Measurement ◽  
Atmospheric Composition ◽  
Climate Feedback ◽  
Data Sets ◽  
Instrumental Performance

Abstract. High-resolution Fourier transform infrared (FTIR) solar observations are particularly relevant for climate studies, as they allow atmospheric gaseous composition and multiple climate processes to be monitored in detail. In this context, the present paper provides an overview of 20 years of FTIR measurements taken in the framework of the NDACC (Network for the Detection of Atmospheric Composition Change) from 1999 to 2018 at the subtropical Izaña Observatory (IZO, Spain). Firstly, long-term instrumental performance is comprehensively assessed, corroborating the temporal stability and reliable instrumental characterization of the two FTIR spectrometers installed at IZO since 1999. Then, the time series of all trace gases contributing to NDACC at IZO are presented (i.e. C2H6, CH4, ClONO2, CO, HCl, HCN, H2CO, HF, HNO3, N2O, NO2, NO, O3, carbonyl sulfide (OCS), and water vapour isotopologues H216O, H218O, and HD16O), reviewing the major accomplishments drawn from these observations. In order to examine the quality and long-term consistency of the IZO FTIR observations, a comparison of those NDACC products for which other high-quality measurement techniques are available at IZO has been performed (i.e. CH4, CO, H2O, NO2, N2O, and O3). This quality assessment was carried out on different timescales to examine what temporal signals are captured by the FTIR records, and to what extent. After 20 years of operation, the IZO NDACC FTIR observations have been found to be very consistent and reliable over time, demonstrating great potential for climate research. Long-term NDACC FTIR data sets, such as IZO, are indispensable tools for the investigation of atmospheric composition trends, multi-year phenomena, and complex climate feedback processes, as well as for the validation of past and present space-based missions and chemistry climate models.

scholarly journals Twenty years of ground-based NDACC FTIR spectrometry at Izaña Observatory – overview and long-term comparison to other techniques

2021 ◽  
Author(s):  
Omaira E. García ◽  
Matthias Schneider ◽  
Eliezer Sepúlveda ◽  
Frank Hase ◽  
Thomas Blumenstock ◽  
...  
Keyword(s):  
Climate Models ◽  
Measurement Techniques ◽  
Temporal Stability ◽  
Quality Measurement ◽  
Atmospheric Composition ◽  
Climate Feedback ◽  
Data Sets ◽  
Instrumental Performance ◽  
Instrumental Characterisation

Abstract. High-resolution Fourier Transform InfraRed (FTIR) solar observations are particularly relevant for climate studies, as they allow atmospheric gaseous composition and multiple climate processes to be monitored in detail. In this context, the present paper provides an overview of 20 years of FTIR measurements taken in the framework of the NDACC (Network for the Detection of Atmospheric Composition Change) from 1999 to 2018 at the subtropical Izaña Observatory (IZO, Spain). Firstly, long-term instrumental performance is comprehensively assessed, corroborating the temporal stability and reliable instrumental characterisation of the two FTIR spectrometers installed at IZO since 1999. Then, the time series of all trace gases contributing to NDACC at IZO are presented (i.e. C2H6, CH4, ClONO2, CO, HCl, HCN, H2CO, HF, HNO3, N2O, NO2, NO, O3, OCS, and water vapour isotopologues H216O, H218O, and HD16O), reviewing the major accomplishments drawn from these observations. In order to examine the quality and long-term consistency of the IZO FTIR observations, a comparison of those NDACC products for which other high-quality measurement techniques are available at IZO has been performed (i.e. CH4, CO, H2O, NO2, N2O, and O3). This quality assessment was carried out on different timescales to examine what temporal signals, and to what extent, are captured by the FTIR records. After 20 years of operation, the IZO NDACC FTIR observations have been found to be very consistent and reliable over time, demonstrating great potential for climate research. Long-term NDACC FTIR data sets, such as IZO, are indispensable tools for the investigation of atmospheric composition trends, multi-year phenomena and complex climate feedback processes, as well as for the validation of past and present space-based missions and chemistry climate models.

scholarly journals A framework for national climate indicators

2018 ◽  
Vol 163 (4) ◽  
pp. 1705-1718 ◽  
Author(s):  
Melissa A. Kenney ◽  
Anthony C. Janetos ◽  
Michael D. Gerst
Keyword(s):  
Conceptual Models ◽  
Indicator System ◽  
Federal Agencies ◽  
Special Issue ◽  
Critical Elements ◽  
Climate Assessment ◽  
Climate Indicators ◽  
National Climate Assessment ◽  
Over Time ◽  
Selection Of

AbstractIndicators have been proposed as critical elements for sustained climate assessment. Indicators provide a foundation for assessing change on an ongoing basis and presenting that information in a manner that is relevant to a broad range of decisions. As part of a sustained US National Climate Assessment, a pilot indicator system was implemented, informed by recommendations and (Kenney et al. 2014; Janetos and Kenney 2015; Kenney et al. Clim Chang 135(1):85–96, 2016). This paper extends this work to recommend a framework and topical categories for a system of climate indicators for the nation. We provide an overview of the indicator system as a whole: its goals, the design criteria for the indicators and the system as a whole, the selection of sectors, the use of conceptual models to transparently identify relevant indicators, examples of the actual indicators proposed, our vision for how the overall network can be used, and how it could evolve over time. Individual papers as part of this special issue provide system or sector-specific details as to how to operationalize the conceptual framework; these recommendations do not imply any decisions that are made ultimately by US federal agencies.

scholarly journals Skill and independence weighting for multi-model assessments

2016 ◽  
Author(s):  
Benjamin Sanderson ◽  
Michael Wehner ◽  
Reto Knutti
Keyword(s):  
Weather Extremes ◽  
Climate Assessment ◽  
Temperature And Precipitation ◽  
Weighted Means ◽  
Relevant Variables ◽  
National Climate Assessment ◽  
Two Parameters ◽  
Precipitation Changes ◽  
Model Weighting

Abstract. We present a weighting strategy for use with the CMIP5 multi-model archive in the 4th National Climate Assessment which considers both skill in the climatological performance of models over North America as well as the inter-dependency of models arising from common parameterizations or tuning practices. The method exploits information relating to the climatological mean state of a number of projection-relevant variables as well as metrics representing long term statistics of weather extremes. The weights, once computed can be used to simply compute weighted means and significance information from an ensemble containing multiple initial condition members from co-dependent models of varying skill. Two parameters in the algorithm determine the degree to which model climatological skill and model uniqueness are rewarded; these parameters are explored and final values are defended with respect to the Assessment. The influence of model weighting on projected temperature and precipitation changes is found to be moderate, partly due to a compensating effect between model skill and uniqueness. However, more aggressive skill weighting and weighting by targeted metrics is found to have a more significant effect on inferred ensemble confidence in future patterns of change for a given projection.

scholarly journals The SSP greenhouse gas concentrations and their extensions to 2500

2019 ◽  
Author(s):  
Malte Meinshausen ◽  
Zebedee Nicholls ◽  
Jared Lewis ◽  
Matthew J. Gidden ◽  
Elisabeth Vogel ◽  
...  
Keyword(s):  
Greenhouse Gases ◽  
Greenhouse Gas ◽  
Radiative Forcing ◽  
Fossil Fuels ◽  
Future Climate Change ◽  
Historical Period ◽  
Concentration Data ◽  
Regional Warming ◽  
Carbon Cycle Model ◽  
Co2 Concentrations

Abstract. Anthropogenic increases of atmospheric greenhouse gas concentrations are the main driver of current and future climate change. The Integrated Assessment community quantified anthropogenic emissions for the Shared Socioeconomic Pathways (SSP) scenarios, each of which represents a different future socio-economic projection and political environment. Here, we provide the greenhouse gas concentration for these SSP scenarios – using the reduced complexity climate-carbon cycle model MAGICC7.0. We extend historical, observationally-based concentration data with SSP concentration projections from 2015 to 2500 for 43 greenhouse gases with monthly and latitudinal resolution. CO2 concentrations by 2100 range from 393 to 1135 ppm for the lowest (SSP1-1.9) and highest (SSP5-8.5) emission scenarios respectively. We also provide the concentration extensions beyond 2100 based on assumptions in the trajectories of fossil fuels and land use change emissions, net negative emissions, and the fraction of non-CO2 emissions. By 2150, CO2 concentrations in the lowest emission scenario are approximately 350 ppm and approximately plateau at that level until 2500, whereas the highest fossil-fuel driven scenario projects CO2 concentrations of 1737 ppm and reaches concentrations beyond 2000 ppm by 2250. We estimate that the share of CO2 in the total radiative forcing contribution of all considered 43 long-lived greenhouse gases increases from today 66 % to roughly 68 % to 85 % by the time of maximum forcing in the 21st century. For this estimation, we updated simple radiative forcing parameterisations that reflect the Oslo Line by Line model results. In comparison to the RCPs, the five main SSPs (SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5) are more evenly spaced in terms of their expected global-mean temperatures, extend to lower 2100 temperatures and sea level rise than the RCP set. Performing 2 pairs of 6-member historical ensembles with CESM1.2.2, we estimate the effect on surface air temperatures of applying latitudinally and seasonally resolved GHG concentrations. We find that the ensemble differences in the MAM season provide a regional warming in higher northern latitudes of up to 0.4 K over the historical period, latitudinally averaged of about 0.1 K, which we estimate to be comparable to the upper bound (∼ 5 % level) of natural variability. In comparison to the comparatively straight line of the last 2000 years, the greenhouse gas concentrations since the onset of the industrial period and this studies’ projections over the next 100 to 500 years unequivocally depict a ‘hockey-stick’ upwards shape – it is a collective choice whether the hothouse pathway is pursued or whether we manage climate damages to the SSP1-1.9 equivalent of around 1.5 °C warming.

The long-term carbon cycle, fossil fuels and atmospheric composition

Nature ◽  
2003 ◽  
Vol 426 (6964) ◽  
pp. 323-326 ◽  
Author(s):  
Robert A. Berner
Keyword(s):  
Carbon Cycle ◽  
Fossil Fuels ◽  
Atmospheric Composition

scholarly journals The shared socio-economic pathway (SSP) greenhouse gas concentrations and their extensions to 2500

2020 ◽  
Vol 13 (8) ◽  
pp. 3571-3605 ◽  
Author(s):  
Malte Meinshausen ◽  
Zebedee R. J. Nicholls ◽  
Jared Lewis ◽  
Matthew J. Gidden ◽  
Elisabeth Vogel ◽  
...  
Keyword(s):  
Greenhouse Gases ◽  
Greenhouse Gas ◽  
Radiative Forcing ◽  
Fossil Fuels ◽  
Future Climate Change ◽  
Historical Period ◽  
Concentration Data ◽  
Regional Warming ◽  
Carbon Cycle Model ◽  
Co2 Concentrations

Abstract. Anthropogenic increases in atmospheric greenhouse gas concentrations are the main driver of current and future climate change. The integrated assessment community has quantified anthropogenic emissions for the shared socio-economic pathway (SSP) scenarios, each of which represents a different future socio-economic projection and political environment. Here, we provide the greenhouse gas concentrations for these SSP scenarios – using the reduced-complexity climate–carbon-cycle model MAGICC7.0. We extend historical, observationally based concentration data with SSP concentration projections from 2015 to 2500 for 43 greenhouse gases with monthly and latitudinal resolution. CO2 concentrations by 2100 range from 393 to 1135 ppm for the lowest (SSP1-1.9) and highest (SSP5-8.5) emission scenarios, respectively. We also provide the concentration extensions beyond 2100 based on assumptions regarding the trajectories of fossil fuels and land use change emissions, net negative emissions, and the fraction of non-CO2 emissions. By 2150, CO2 concentrations in the lowest emission scenario are approximately 350 ppm and approximately plateau at that level until 2500, whereas the highest fossil-fuel-driven scenario projects CO2 concentrations of 1737 ppm and reaches concentrations beyond 2000 ppm by 2250. We estimate that the share of CO2 in the total radiative forcing contribution of all considered 43 long-lived greenhouse gases increases from 66 % for the present day to roughly 68 % to 85 % by the time of maximum forcing in the 21st century. For this estimation, we updated simple radiative forcing parameterizations that reflect the Oslo Line-By-Line model results. In comparison to the representative concentration pathways (RCPs), the five main SSPs (SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) are more evenly spaced and extend to lower 2100 radiative forcing and temperatures. Performing two pairs of six-member historical ensembles with CESM1.2.2, we estimate the effect on surface air temperatures of applying latitudinally and seasonally resolved GHG concentrations. We find that the ensemble differences in the March–April–May (MAM) season provide a regional warming in higher northern latitudes of up to 0.4 K over the historical period, latitudinally averaged of about 0.1 K, which we estimate to be comparable to the upper bound (∼5 % level) of natural variability. In comparison to the comparatively straight line of the last 2000 years, the greenhouse gas concentrations since the onset of the industrial period and this studies' projections over the next 100 to 500 years unequivocally depict a “hockey-stick” upwards shape. The SSP concentration time series derived in this study provide a harmonized set of input assumptions for long-term climate science analysis; they also provide an indication of the wide set of futures that societal developments and policy implementations can lead to – ranging from multiple degrees of future warming on the one side to approximately 1.5 ∘C warming on the other.

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