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6 results on '"Bruhwiler, Lori"'

1. Variability and quasi-decadal changes in the methane budget over the period 2000–2012

Author

Saunois, Marielle, Bousquet, Philippe, Poulter, Ben, Peregon, Anna, Ciais, Philippe, Canadell, Josep G, Dlugokencky, Edward J, Etiope, Giuseppe, Bastviken, David, Houweling, Sander, Janssens-Maenhout, Greet, Tubiello, Francesco N, Castaldi, Simona, Jackson, Robert B, Alexe, Mihai, Arora, Vivek K, Beerling, David J, Bergamaschi, Peter, Blake, Donald R, Brailsford, Gordon, Bruhwiler, Lori, Crevoisier, Cyril, Crill, Patrick, Covey, Kristofer, Frankenberg, Christian, Gedney, Nicola, Höglund-Isaksson, Lena, Ishizawa, Misa, Ito, Akihiko, Joos, Fortunat, Kim, Heon-Sook, Kleinen, Thomas, Krummel, Paul, Lamarque, Jean-François, Langenfelds, Ray, Locatelli, Robin, Machida, Toshinobu, Maksyutov, Shamil, Melton, Joe R, Morino, Isamu, Naik, Vaishali, O'Doherty, Simon, Parmentier, Frans-Jan W, Patra, Prabir K, Peng, Changhui, Peng, Shushi, Peters, Glen P, Pison, Isabelle, Prinn, Ronald, Ramonet, Michel, Riley, William J, Saito, Makoto, Santini, Monia, Schroeder, Ronny, Simpson, Isobel J, Spahni, Renato, Takizawa, Atsushi, Thornton, Brett F, Tian, Hanqin, Tohjima, Yasunori, Viovy, Nicolas, Voulgarakis, Apostolos, Weiss, Ray, Wilton, David J, Wiltshire, Andy, Worthy, Doug, Wunch, Debra, Xu, Xiyan, Yoshida, Yukio, Zhang, Bowen, Zhang, Zhen, and Zhu, Qiuan

Subjects
Earth Sciences, Atmospheric Sciences, Climate Action, Astronomical and Space Sciences, Meteorology & Atmospheric Sciences, Atmospheric sciences, Climate change science
Abstract

Following the recent Global Carbon Project (GCP) synthesis of the decadal methane (CH4) budget over 2000-2012 (Saunois et al., 2016), we analyse here the same dataset with a focus on quasi-decadal and inter-annual variability in CH4 emissions. The GCP dataset integrates results from top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up models (including process-based models for estimating land surface emissions and atmospheric chemistry), inventories of anthropogenic emissions, and data-driven approaches. The annual global methane emissions from top-down studies, which by construction match the observed methane growth rate within their uncertainties, all show an increase in total methane emissions over the period 2000-2012, but this increase is not linear over the 13 years. Despite differences between individual studies, the mean emission anomaly of the top-down ensemble shows no significant trend in total methane emissions over the period 2000-2006, during the plateau of atmospheric methane mole fractions, and also over the period 2008-2012, during the renewed atmospheric methane increase. However, the top-down ensemble mean produces an emission shift between 2006 and 2008, leading to 22 [16-32]Tg CH4yr-1 higher methane emissions over the period 2008-2012 compared to 2002-2006. This emission increase mostly originated from the tropics, with a smaller contribution from mid-latitudes and no significant change from boreal regions. The regional contributions remain uncertain in top-down studies. Tropical South America and South and East Asia seem to contribute the most to the emission increase in the tropics. However, these two regions have only limited atmospheric measurements and remain therefore poorly constrained. The sectorial partitioning of this emission increase between the periods 2002-2006 and 2008-2012 differs from one atmospheric inversion study to another. However, all top-down studies suggest smaller changes in fossil fuel emissions (from oil, gas, and coal industries) compared to the mean of the bottom-up inventories included in this study. This difference is partly driven by a smaller emission change in China from the top-down studies compared to the estimate in the Emission Database for Global Atmospheric Research (EDGARv4.2) inventory, which should be revised to smaller values in a near future. We apply isotopic signatures to the emission changes estimated for individual studies based on five emission sectors and find that for six individual top-down studies (out of eight) the average isotopic signature of the emission changes is not consistent with the observed change in atmospheric 13CH4. However, the partitioning in emission change derived from the ensemble mean is consistent with this isotopic constraint. At the global scale, the top-down ensemble mean suggests that the dominant contribution to the resumed atmospheric CH4 growth after 2006 comes from microbial sources (more from agriculture and waste sectors than from natural wetlands), with an uncertain but smaller contribution from fossil CH4 emissions. In addition, a decrease in biomass burning emissions (in agreement with the biomass burning emission databases) makes the balance of sources consistent with atmospheric 13CH4 observations. In most of the top-down studies included here, OH concentrations are considered constant over the years (seasonal variations but without any inter-annual variability). As a result, the methane loss (in particular through OH oxidation) varies mainly through the change in methane concentrations and not its oxidants. For these reasons, changes in the methane loss could not be properly investigated in this study, although it may play a significant role in the recent atmospheric methane changes as briefly discussed at the end of the paper.

Published
2017

2. The global methane budget 2000–2012

Author

Saunois, Marielle, Bousquet, Philippe, Poulter, Ben, Peregon, Anna, Ciais, Philippe, Canadell, Josep G, Dlugokencky, Edward J, Etiope, Giuseppe, Bastviken, David, Houweling, Sander, Janssens-Maenhout, Greet, Tubiello, Francesco N, Castaldi, Simona, Jackson, Robert B, Alexe, Mihai, Arora, Vivek K, Beerling, David J, Bergamaschi, Peter, Blake, Donald R, Brailsford, Gordon, Brovkin, Victor, Bruhwiler, Lori, Crevoisier, Cyril, Crill, Patrick, Covey, Kristofer, Curry, Charles, Frankenberg, Christian, Gedney, Nicola, Höglund-Isaksson, Lena, Ishizawa, Misa, Ito, Akihiko, Joos, Fortunat, Kim, Heon-Sook, Kleinen, Thomas, Krummel, Paul, Lamarque, Jean-François, Langenfelds, Ray, Locatelli, Robin, Machida, Toshinobu, Maksyutov, Shamil, McDonald, Kyle C, Marshall, Julia, Melton, Joe R, Morino, Isamu, Naik, Vaishali, O'Doherty, Simon, Parmentier, Frans-Jan W, Patra, Prabir K, Peng, Changhui, Peng, Shushi, Peters, Glen P, Pison, Isabelle, Prigent, Catherine, Prinn, Ronald, Ramonet, Michel, Riley, William J, Saito, Makoto, Santini, Monia, Schroeder, Ronny, Simpson, Isobel J, Spahni, Renato, Steele, Paul, Takizawa, Atsushi, Thornton, Brett F, Tian, Hanqin, Tohjima, Yasunori, Viovy, Nicolas, Voulgarakis, Apostolos, van Weele, Michiel, van der Werf, Guido R, Weiss, Ray, Wiedinmyer, Christine, Wilton, David J, Wiltshire, Andy, Worthy, Doug, Wunch, Debra, Xu, Xiyan, Yoshida, Yukio, Zhang, Bowen, Zhang, Zhen, and Zhu, Qiuan

Subjects
Earth Sciences, Atmospheric Sciences, Climate Action, Geochemistry, Physical Geography and Environmental Geoscience, Atmospheric sciences, Geoinformatics, Physical geography and environmental geoscience
Abstract

The global methane (CH4) budget is becoming an increasingly important component for managing realistic pathways to mitigate climate change. This relevance, due to a shorter atmospheric lifetime and a stronger warming potential than carbon dioxide, is challenged by the still unexplained changes of atmospheric CH4 over the past decade. Emissions and concentrations of CH4 are continuing to increase, making CH4 the second most important human-induced greenhouse gas after carbon dioxide. Two major difficulties in reducing uncertainties come from the large variety of diffusive CH4 sources that overlap geographically, and from the destruction of CH4 by the very short-lived hydroxyl radical (OH). To address these difficulties, we have established a consortium of multi-disciplinary scientists under the umbrella of the Global Carbon Project to synthesize and stimulate research on the methane cycle, and producing regular (g1/4 biennial) updates of the global methane budget. This consortium includes atmospheric physicists and chemists, biogeochemists of surface and marine emissions, and socio-economists who study anthropogenic emissions. Following Kirschke et al. (2013), we propose here the first version of a living review paper that integrates results of top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up models, inventories and data-driven approaches (including process-based models for estimating land surface emissions and atmospheric chemistry, and inventories for anthropogenic emissions, data-driven extrapolations). For the 2003-2012 decade, global methane emissions are estimated by top-down inversions at 558g Tgg CH4g yrg'1, range 540-568. About 60g % of global emissions are anthropogenic (range 50-65g %). Since 2010, the bottom-up global emission inventories have been closer to methane emissions in the most carbon-intensive Representative Concentrations Pathway (RCP8.5) and higher than all other RCP scenarios. Bottom-up approaches suggest larger global emissions (736g Tgg CH4g yrg'1, range 596-884) mostly because of larger natural emissions from individual sources such as inland waters, natural wetlands and geological sources. Considering the atmospheric constraints on the top-down budget, it is likely that some of the individual emissions reported by the bottom-up approaches are overestimated, leading to too large global emissions. Latitudinal data from top-down emissions indicate a predominance of tropical emissions (g1/4 64g % of the global budget, http://doi.org/10.3334/CDIAC/GLOBAL-METHANE-BUDGET-2016-V1.1) and the Global Carbon Project.

Published
2016

3. U.S. emissions of HFC‐134a derived for 2008–2012 from an extensive flask‐air sampling network

Author

Hu, Lei, Montzka, Stephen A, Miller, John B, Andrews, Aryln E, Lehman, Scott J, Miller, Benjamin R, Thoning, Kirk, Sweeney, Colm, Chen, Huilin, Godwin, David S, Masarie, Kenneth, Bruhwiler, Lori, Fischer, Marc L, Biraud, Sebastien C, Torn, Margaret S, Mountain, Marikate, Nehrkorn, Thomas, Eluszkiewicz, Janusz, Miller, Scot, Draxler, Roland R, Stein, Ariel F, Hall, Bradley D, Elkins, James W, and Tans, Pieter P

Subjects
Earth Sciences, Atmospheric Sciences, Climate Action, HFC-134a, emissions, inverse modeling, atmosphere based, US, Physical Geography and Environmental Geoscience, Atmospheric sciences, Climate change science
Abstract

U.S. national and regional emissions of HFC-134a are derived for 20082012 based on atmospheric observations from ground and aircraft sites across the U.S. and a newly developed regional inverse model. Synthetic data experiments were first conducted to optimize the model assimilation design and to assess model-data mismatch errors and prior flux error covariances computed using a maximumlikelihood estimation technique. The synthetic data experiments also tested the sensitivity of derived national and regional emissions to a range of assumed prior emissions, with the goal of designing a system that was minimally reliant on the prior. We then explored the influence of additional sources of error in inversions with actual observations, such as those associated with background mole fractions and transport uncertainties. Estimated emissions of HFC-134a range from 52 to 61 Gg yr-1 for the contiguous U.S. during 20082012 for inversions using air transport from Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model driven by the 12km resolution meteorogical data from North American Mesoscale Forecast System (NAM12) and all tested combinations of prior emissions and background mole fractions. Estimated emissions for 20082010 were 20% lower when specifying alternative transport from Stochastic Time-Inverted Lagrangian Transport (STILT) model driven by the Weather Research and Forecasting (WRF) meteorology. Our estimates (for HYSPLIT-NAM12) are consistent with annual emissions reported by U.S. Environmental Protection Agency for the full study interval. The results suggest a 1020% drop in U.S. national HFC-134a emission in 2009 coincident with a reduction in transportation-related fossil fuel CO2 emissions, perhaps related to the economic recession. All inversions show seasonal variation in national HFC-134a emissions in all years, with summer emissions greater than winter emissions by 2050%.

Published
2015

4. Chemistry and the Linkages between Air Quality and Climate Change

Author

von Schneidemesser, Erika, Monks, Paul S., Allan, James D., Bruhwiler, Lori, Forster, Piers, Fowler, David, Lauer, Axel, Morgan, William T., Paasonen, Pauli, Righi, Mattia, Sindelarova, Katerina, Sutton, Mark A., Institute for Advanced Sustainability Studies [Potsdam] (IASS), Department of Chemistry [Leicester], University of Leicester, School of Earth, Atmospheric and Environmental Sciences [Manchester] (SEAES), University of Manchester [Manchester], National Centre for Atmospheric Science [Manchester] (NCAS), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), University of Leeds, Centre for Ecology and Hydrology [Edinburgh] (CEH), Natural Environment Research Council (NERC), Department of Physics [Helsinki], Falculty of Science [Helsinki], University of Helsinki-University of Helsinki, DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), Faculty of Mathematics and Physics [Praha/Prague], Charles University [Prague] (CU), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Physics, Aerosol-Cloud-Climate -Interactions (ACCI), and Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], GREENHOUSE-GAS EMISSIONS, aerosol, [SDE.MCG]Environmental Sciences/Global Changes, education, CLOUD DROPLET ACTIVATION, 116 Chemical sciences, Gaseous pollutants, UNITED-STATES, VOLATILITY BASIS-SET, air quality, REPRESENTATIVE CONCENTRATION PATHWAYS, Atmospheric Sciences, Chemistry, BLACK CARBON AEROSOLS, climate change, SECONDARY ORGANIC AEROSOL, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, SURFACE OZONE, BIOMASS BURNING EMISSIONS, INTERCOMPARISON PROJECT ACCMIP
Abstract

International audience; Climate change and air pollution are critical environmental issues both in the here and now and for the coming decades. A recent OECD report found that unless action is taken, air pollution will be the largest environmental cause of premature death worldwide by 2050. Already, air pollution levels in Asia are far above acceptable levels for human health, and even in Europe, the vast majority of the urban population was exposed to air pollution concentrations exceeding the EU daily limit values, and especially the stricter WHO air quality guidelines in the past decade. The most recent synthesis of climate change research as presented in the fifth IPCC Assessment Report (AR5) states that the warming of the climate system is unequivocal, recognizing the dominant cause as human influence, and providing evidence for a 43% higher total (from 1750 to the present) anthropogenic radiative forcing (RF) than was reported in 2005 from the previous assessment report.

Published
2015

5. International Arctic Systems for Observing the Atmosphere: An International Polar Year Legacy Consortium.

Author

Uttal, Taneil, Starkweather, Sandra, Drummond, James R., Vihma, Timo, Makshtas, Alexander P., Darby, Lisa S., Burkhart, John F., Cox, Christopher J., Schmeisser, Lauren N., Haiden, Thomas, Maturilli, Marion, Shupe, Matthew D., De Boer, Gijs, Saha, Auromeet, Grachev, Andrey A., Crepinsek, Sara M., Bruhwiler, Lori, Goodison, Barry, McArthur, Bruce, and Walden, Von P.

Subjects
METEOROLOGY, CLIMATOLOGY, GLACIOLOGY, OCEANOGRAPHY, ATMOSPHERIC sciences
Abstract

International Arctic Systems for Observing the Atmosphere (IASOA) activities and partnerships were initiated as a part of the 2007-09 International Polar Year (IPY) and are expected to continue for many decades as a legacy program. The IASOA focus is on coordinating intensive measurements of the Arctic atmosphere collected in the United States, Canada, Russia, Norway, Finland, and Greenland to create synthesis science that leads to an understanding of why and not just how the Arctic atmosphere is evolving. The IASOA premise is that there are limitations with Arctic modeling and satellite observations that can only be addressed with boots-on-the-ground, in situ observations and that the potential of combining individual station and network measurements into an integrated observing system is tremendous. The IASOA vision is that by further integrating with other network observing programs focusing on hydrology, glaciology, oceanography, terrestrial, and biological systems it will be possible to understand the mechanisms of the entire Arctic system, perhaps well enough for humans to mitigate undesirable variations and adapt to inevitable change. [ABSTRACT FROM AUTHOR]

Published
2016
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6. The global methane budget 2000-2012

Author

Akihiko Ito, Philippe Ciais, Peter Bergamaschi, Greet Janssens-Maenhout, David J. Beerling, Cyril Crevoisier, Philippe Bousquet, Julia Marshall, Simona Castaldi, Isabelle Pison, Heon Sook Kim, Yasunori Tohjima, Jean-Francois Lamarque, Atsushi Takizawa, Charles L. Curry, Debra Wunch, Kyle C. McDonald, Michel Ramonet, David Bastviken, Simon O'Doherty, Josep G. Canadell, Robin Locatelli, Francesco N. Tubiello, Prabir K. Patra, P. Steele, Brett F. Thornton, Catherine Prigent, Sander Houweling, Toshinobu Machida, David J. Wilton, Joe R. Melton, Ronald G. Prinn, William J. Riley, Edward J. Dlugokencky, Monia Santini, Giuseppe Etiope, Doug Worthy, Guido R. van der Werf, Christian Frankenberg, Shushi Peng, Vivek K. Arora, Patrick M. Crill, Ray F. Weiss, Nicolas Viovy, Michiel van Weele, Anna Peregon, Shamil Maksyutov, Vaishali Naik, Zhen Zhang, Thomas Kleinen, Lori Bruhwiler, Yukio Yoshida, Lena Höglund-Isaksson, Kristofer R. Covey, Fortunat Joos, Misa Ishizawa, Bowen Zhang, Christine Wiedinmyer, Ronny Schroeder, Nicola Gedney, Hanqin Tian, Changhui Peng, Apostolos Voulgarakis, Mihai Alexe, Victor Brovkin, Ray L. Langenfelds, Isamu Morino, Glen P. Peters, Xiyan Xu, Andy Wiltshire, Isobel J. Simpson, Ben Poulter, Marielle Saunois, Qiuan Zhu, Donald R. Blake, Paul B. Krummel, Frans-Jan W. Parmentier, Makoto Saito, Gordon Brailsford, Robert B. Jackson, Renato Spahni, Earth and Climate, Hydrology and Geo-environmental sciences, Faculty of Earth and Life Sciences, Saunois, Marielle, Bousquet, Philippe, Poulter, Ben, Peregon, Anna, Ciais, Philippe, Canadell Josep, G, Dlugokencky Edward, J., Etiope, Giuseppe, Bastviken, David, Houweling, Sander, Janssens Maenhout, Greet, Tubiello Francesco, N., Castaldi, Simona, Jackson Robert, B., Alexe, Mihai, Arora Vivek, K., Beerling David, J., Bergamaschi, Peter, Blake Donald, R., Brailsford, Gordon, Brovkin, Victor, Bruhwiler, Lori, Crevoisier, Cyril, Crill, Patrick, Covey, Kristofer, Curry, Charle, Frankenberg, Christian, Gedney, Nicola, Höglund Isaksson, Lena, Ishizawa, Misa, Ito, Akihiko, Joos, Fortunat, Kim Heon, Sook, Kleinen, Thoma, Krummel, Paul, Lamarque Jean, Françoi, Langenfelds, Ray, Locatelli, Robin, Machida, Toshinobu, Maksyutov, Shamil, McDonald Kyle, C., Marshall, Julia, Melton Joe, R., Morino, Isamu, Naik Vaishali, Oapo, Doherty, Simon, Parmentier Frans Jan, W., Patra Prabir, K., Peng, Changhui, Peng, Shushi, Peters Glen, P., Pison, Isabelle, Prigent, Catherine, Prinn, Ronald, Ramonet, Michel, Riley William, J., Saito, Makoto, Santini, Monia, Schroeder, Ronny, Simpson Isobel, J., Spahni, Renato, Steele, Paul, Takizawa, Atsushi, Thornton Brett, F., Tian, Hanqin, Tohjima, Yasunori, Viovy, Nicola, Voulgarakis, Apostolo, van Weele, Michiel, van der Werf Guido, R., Weiss, Ray, Wiedinmyer, Christine, Wilton David, J., Wiltshire, Andy, Worthy, Doug, Wunch, Debra, Xu, Xiyan, Yoshida, Yukio, Zhang, Bowen, Zhang, Zhen, Zhu, Qiuan, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), NASA Goddard Space Flight Center (GSFC), ICOS-ATC (ICOS-ATC), Istituto Nazionale di Geofisica e Vulcanologia, The Department of Thematic Studies - Water and Environmental Studies, Linköping University (LIU), SRON Netherlands Institute for Space Research (SRON), European Commission - Joint Research Centre [Ispra] (JRC), LM, Canadian Centre for Climate Modelling and Analysis (CCCma), Environment and Climate Change Canada, Department of Animal and Plant Sciences, University of Sheffield [Sheffield], JRC Institute for Environment and Sustainability (IES), Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Tropospheric sounding, assimilation, and modeling group [JPL], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH)-NASA-California Institute of Technology (CALTECH), National Institute for Environmental Studies (NIES), Climate and Environmental Physics [Bern] (CEP), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE), Atmospheric Chemistry Division [Boulder], National Center for Atmospheric Research [Boulder] (NCAR), Oceans and Atmosphere, CSIRO, Strathom Energie, Centre Européen de Réalité Virtuelle (CERV), École Nationale d'Ingénieurs de Brest (ENIB), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Université du Québec à Trois-Rivières (UQTR), ICOS-RAMCES (ICOS-RAMCES), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Shandong Agricultural University (SDAU), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Department of Physics [Imperial College London], Imperial College London, Royal Netherlands Meteorological Institute (KNMI), Faculty of Earth and Life Sciences [Amsterdam] (FALW), Vrije Universiteit Amsterdam [Amsterdam] (VU), Scripps Institution of Oceanography (SIO - UC San Diego), University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC), Met Office Hadley Centre for Climate Change (MOHC), United Kingdom Met Office [Exeter], Climate Research Division [Toronto], California Institute of Technology (CALTECH), Laboratoire de Physique et d'Etude des Matériaux (UMR 8213) (LPEM), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), USC Viterbi School of Engineering, University of Southern California (USC), Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Prinn, Ronald G, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Universität Bern [Bern]-Universität Bern [Bern], Scripps Institution of Oceanography (SIO), and University of California-University of California

Subjects
010504 meteorology & atmospheric sciences, Naturgeografi, TRACE GASES, 010501 environmental sciences, Atmospheric sciences, 7. Clean energy, 01 natural sciences, Physical Geography and Environmental Geoscience, Methane, chemistry.chemical_compound, Natural gas, 11. Sustainability, SDG 13 - Climate Action, Meteorology & Atmospheric Sciences, Geosciences, Multidisciplinary, Greenhouse effect, lcsh:Environmental sciences, ComputingMilieux_MISCELLANEOUS, lcsh:GE1-350, [PHYS]Physics [physics], GREENHOUSE-GAS EMISSIONS, methane, lcsh:QE1-996.5, Geology, PAST 2 DECADES, Carbon project, Atmospheric chemistry, Physical Sciences, hydroxyl, Earth and Related Environmental Sciences, Wetland methane emissions, BIOMASS BURNING EMISSIONS, NATURAL-GAS, PROCESS-BASED MODEL, TROPOSPHERIC METHANE, 530 Physics, methane sources, Climate change, Atmospheric Sciences, ATMOSPHERIC HYDROXYL RADICALS, SDG 14 - Life Below Water, ISOTOPIC COMPOSITION, 550 Earth sciences & geology, 0105 earth and related environmental sciences, global model, Science & Technology, business.industry, Environmental engineering, Geovetenskap och miljövetenskap, 15. Life on land, methane budget, lcsh:Geology, Climate Action, Geochemistry, chemistry, Physical Geography, 13. Climate action, Greenhouse gas, General Earth and Planetary Sciences, Environmental science, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], INTERCOMPARISON PROJECT ACCMIP
Abstract

The global methane (CH4) budget is becoming an increasingly important component for managing realistic pathways to mitigate climate change. This relevance, due to a shorter atmospheric lifetime and a stronger warming potential than carbon dioxide, is challenged by the still unexplained changes of atmospheric CH4 over the past decade. Emissions and concentrations of CH4 are continuing to increase, making CH4 the second most important human-induced greenhouse gas after carbon dioxide. Two major difficulties in reducing uncertainties come from the large variety of diffusive CH4 sources that overlap geographically, and from the destruction of CH4 by the very short-lived hydroxyl radical (OH). To address these difficulties, we have established a consortium of multi-disciplinary scientists under the umbrella of the Global Carbon Project to synthesize and stimulate research on the methane cycle, and producing regular (similar to biennial) updates of the global methane budget. This consortium includes atmospheric physicists and chemists, biogeochemists of surface and marine emissions, and socio-economists who study anthropogenic emissions. Following Kirschke et al. (2013), we propose here the first version of a living review paper that integrates results of top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up models, inventories and data-driven approaches (including process-based models for estimating land surface emissions and atmospheric chemistry, and inventories for anthropogenic emissions, data-driven extrapolations). For the 2003-2012 decade, global methane emissions are estimated by top-down inversions at 558 TgCH(4) yr(-1), range 540-568. About 60% of global emissions are anthropogenic (range 50-65 %). Since 2010, the bottom-up global emission inventories have been closer to methane emissions in the most carbon-intensive Representative Concentrations Pathway (RCP8.5) and higher than all other RCP scenarios. Bottom-up approaches suggest larger global emissions (736 TgCH(4) yr(-1), range 596-884) mostly because of larger natural emissions from individual sources such as inland waters, natural wetlands and geological sources. Considering the atmospheric constraints on the top-down budget, it is likely that some of the individual emissions reported by the bottom-up approaches are overestimated, leading to too large global emissions. Latitudinal data from top-down emissions indicate a predominance of tropical emissions (similar to 64% of the global budget, amp;lt;30 degrees N) as compared to mid (similar to 32 %, 30-60 degrees N) and high northern latitudes (similar to 4 %, 60-90 degrees N). Top-down inversions consistently infer lower emissions in China (similar to 58 TgCH(4) yr(-1), range 51-72, -14 %) and higher emissions in Africa (86 TgCH(4) yr(-1), range 73-108, + 19 %) than bottom-up values used as prior estimates. Overall, uncertainties for anthropogenic emissions appear smaller than those from natural sources, and the uncertainties on source categories appear larger for top-down inversions than for bottom-up inventories and models. The most important source of uncertainty on the methane budget is attributable to emissions from wetland and other inland waters. We show that the wetland extent could contribute 30-40% on the estimated range for wetland emissions. Other priorities for improving the methane budget include the following: (i) the development of process-based models for inland-water emissions, (ii) the intensification of methane observations at local scale (flux measurements) to constrain bottom-up land surface models, and at regional scale (surface networks and satellites) to constrain top-down inversions, (iii) improvements in the estimation of atmospheric loss by OH, and (iv) improvements of the transport models integrated in top-down inversions. The data presented here can be downloaded from the Carbon Dioxide Information Analysis Center (http://doi.org/10.3334/CDIAC/GLOBAL_METHANE_BUDGET_2016_V1.1) and the Global Carbon Project. Funding Agencies|Swiss National Science Foundation; NASA [NNX14AF93G, NNX14AO73G]; National Environmental Science Program - Earth Systems and Climate Change Hub; European Commission [283576, 633080]; ESA Climate Change Initiative Greenhouse Gases Phase 2 project; US Department of Energy, BER [DE-AC02-05CH11231]; FAO member countries; Environment Research and Technology Development Fund of the Ministry of the Environment, Japan [2-1502]; ERC [322998]; NERC [NE/J00748X/1]; Swedish Research Council VR; Research Council of Norway [244074]; NSF [1243232, 1243220]; National Science and Engineering Research Council of Canada (NSERC); Chinas QianRen Program; CSIRO Australia; Australian Bureau of Meteorology; Australian Institute of Marine Science; Australian Antarctic Division; NOAA USA; Meteorological Service of Canada; National Aeronautic and Space Administration (NASA) [NAG5-12669, NNX07AE89G, NNX11AF17G, NNX07AE87G, NNX07AF09G, NNX11AF15G, NNX11AF16G]; Department of Energy and Climate Change (DECC, UK) [GA01081]; Commonwealth Scientific and Industrial Research Organization (CSIRO Australia); Bureau of Meteorology (Australia); Joint DECC/Defra Met Office Hadley Centre Climate Programme [GA01101]

Published
2016

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