DOI: 10.5061/dryad.7wm37pw0j
title: Net greenhouse gas balance in U.S. croplands: How can soils be a part of the climate solution?

description: Agricultural soils play a dual role in regulating the Earth’s climate by
 releasing or sequestering carbon dioxide (CO2) in soil organic carbon
 (SOC) and emitting non-CO2 greenhouse gases (GHGs) such as nitrous oxide
 (N2O) and methane (CH4). To understand how agricultural soils can play a
 role in climate solutions requires a comprehensive assessment of net soil
 GHG balance (i.e., sum of SOC-sequestered CO2 and non-CO2 GHG emissions)
 and the underlying controls. Herein, we used a model-data integration
 approach to understand and quantify how natural and anthropogenic factors
 have affected the magnitude and spatiotemporal variations of the net soil
 GHG balance in U.S. croplands during 1960-2018. Specifically, we used the
 Dynamic Land Ecosystem Model (DLEM) for regional simulations and used
 field observations of SOC sequestration rates and N2O and CH4 emissions to
 calibrate, validate, and corroborate model simulations. Results show that
 U.S. agricultural soils sequestered 13.2±1.16 Tg CO2-C yr-1 in SOC (at a
 depth of 3.5 m) during 1960-2018 and emitted 0.39±0.02  Tg N2O-N
 yr-1 and 0.21±0.01  Tg CH4-C yr-1, respectively. Based on the
 GWP100 metric (global warming potential on a 100-year time horizon), the
 estimated national net GHG emission rate from agricultural soils was
 122.3±11.46  Tg CO2-eq yr-1, thus contributing to climate
 warming. The sequestered SOC offset ~28% of the climate-warming effects
 resulting from non-CO2 GHG emissions, and this offsetting effect increased
 over time. Increased nitrogen fertilizer use was the dominant factor
 contributing to the increase in net GHG emissions during 1960-2018,
 explaining ~47% of total changes. In contrast, reduced cropland area, the
 adoption of agricultural conservation practices (e.g., reduced tillage),
 and rising atmospheric CO2 levels attenuated net GHG emissions from U.S.
 croplands. Our study highlights the importance of concurrently quantifying
 SOC-sequestered CO2 and non-CO2 GHG emissions for developing effective
 agricultural climate change mitigation measures.
description: # Net greenhouse gas balance in U.S. croplands: How can soils be a part of
 the climate solution? ## Author information Yongfa You [1,2,3], Hanqin
 Tian [1,2*], Shufen Pan [1,3,4], Hao Shi [5], Chaoqun Lu [6], William D.
 Batchelor [7], Bo Cheng [7], Dafeng Hui [8], David Kicklighter [9],
 Xin-Zhong Liang [10], Xiaoyong Li [1,2,5], Jerry Melillo [9], Naiqing Pan
 [1,2], Stephen A. Prior [11], John Reilly [12] \[1] Center for Earth
 System Science and Global Sustainability (CES3), Boston College, Chestnut
 Hill, MA, USA \[2] Schiller Institute for Integrated Science and Society,
 Department of Earth and Environmental Sciences, Boston College, Chestnut
 Hill, MA, USA \[3] International Center for Climate and Global Change
 Research, College of Forestry, Wildlife and Environment, Auburn
 University, Auburn, AL, USA \[4] Department of Engineering and
 Environmental Studies Program, Boston College, Chestnut Hill, MA, USA \[5]
 State Key Laboratory of Urban and Regional Ecology, Research Center for
 Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
 \[6] Department of Ecology, Evolution, and Organismal Biology, Iowa State
 University, Ames, IA, USA \[7] Biosystems Engineering Department, Auburn
 University, Auburn, AL, USA \[8] Department of Biological Sciences,
 Tennessee State University, Nashville, Tennessee, USA \[9] The Ecosystems
 Center, Marine Biological Laboratory, Woods Hole, MA, USA \[10] Department
 of Atmospheric and Oceanic Science and Earth System Science
 Interdisciplinary Center, University of Maryland, College Park, MD, USA
 \[11] USDA-ARS National Soil Dynamics Laboratory, Auburn, AL, USA \[12]
 Joint Program on the Science and Policy of Global Change, Massachusetts
 Institute of Technology, MA, USA \**Correspondence: Dr. Hanqin Tian,
 * ##### **Dataset DOI:**
 ## **Abstract** In this
 study, we used a model-data integration approach to quantify the net
 greenhouse gas (GHG) balance of U.S. croplands and unravel the relative
 contribution of underlying drivers. The estimated national net GHG balance
 during 1960–2018 was 122.3 Tg CO2‐eq year−1, in which sequestrated soil
 organic carbon (SOC) offset approximately 28% of the climate‐warming
 effects resulting from non‐CO2 GHG emissions. Our study underscores the
 need to concurrently consider both CO2 sequestration in SOC and non‐CO2
 GHG emissions when developing effective agricultural climate change
 mitigation strategies. ## **Usage notes** The dataset includes spatially
 explicit annual SOC sequestration rates, nitrous oxide (N2O) emissions,
 and methane (CH4) emissions in U.S. croplands, covering the period from
 1960 to 2018. These data were simulated using a process-based terrestrial
 biosphere model (i.e., Dynamic Land Ecosystem Model). The spatial
 resolution of the dataset is 5 arc-minutes by 5 arc-minutes. The units for
 SOC sequestration rate and CH4 emissions are g C/m2, and the unit for N2O
 emissions is g N/m2. This dataset is saved in a binary format, with the
 suffix .bin being the data file and the suffix .hdr being the header file.
 Missing values are denoted by -9999. ## **Resolution and spatial
 coverage** (1) Spatial resolution: 5 arc-minutes by 5 arc-minutes (2)
 Temporal resolution: Annual data from 1960 to 2018 (3) Spatial coverage:
 the Contiguous United States ## **Unit** (1) SOC sequestration rate (g
 C/m2) (2) N2O emission (g N/m2) (3) CH4 emission (g C/m2) ## **Datasets
 included** ##### (1) SOC sequestration rate: SOCSequestration_1960.hdr:
 Header file of spatial map of soil organic carbon sequestration rate in
 1960 SOCSequestration_1960.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1960 SOCSequestration_1961.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1961
 SOCSequestration_1961.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1961 SOCSequestration_1962.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1962
 SOCSequestration_1962.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1962 SOCSequestration_1963.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1963
 SOCSequestration_1963.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1963 SOCSequestration_1964.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1964
 SOCSequestration_1964.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1964 SOCSequestration_1965.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1965
 SOCSequestration_1965.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1965 SOCSequestration_1966.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1966
 SOCSequestration_1966.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1966 SOCSequestration_1967.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1967
 SOCSequestration_1967.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1967 SOCSequestration_1968.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1968
 SOCSequestration_1968.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1968 SOCSequestration_1969.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1969
 SOCSequestration_1969.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1969 SOCSequestration_1970.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1970
 SOCSequestration_1970.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1970 SOCSequestration_1971.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1971
 SOCSequestration_1971.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1971 SOCSequestration_1972.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1972
 SOCSequestration_1972.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1972 SOCSequestration_1973.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1973
 SOCSequestration_1973.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1973 SOCSequestration_1974.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1974
 SOCSequestration_1974.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1974 SOCSequestration_1975.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1975
 SOCSequestration_1975.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1975 SOCSequestration_1976.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1976
 SOCSequestration_1976.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1976 SOCSequestration_1977.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1977
 SOCSequestration_1977.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1977 SOCSequestration_1978.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1978
 SOCSequestration_1978.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1978 SOCSequestration_1979.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1979
 SOCSequestration_1979.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1979 SOCSequestration_1980.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1980
 SOCSequestration_1980.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1980 SOCSequestration_1981.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1981
 SOCSequestration_1981.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1981 SOCSequestration_1982.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1982
 SOCSequestration_1982.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1982 SOCSequestration_1983.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1983
 SOCSequestration_1983.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1983 SOCSequestration_1984.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1984
 SOCSequestration_1984.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1984 SOCSequestration_1985.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1985
 SOCSequestration_1985.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1985 SOCSequestration_1986.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1986
 SOCSequestration_1986.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1986 SOCSequestration_1987.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1987
 SOCSequestration_1987.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1987 SOCSequestration_1988.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1988
 SOCSequestration_1988.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1988 SOCSequestration_1989.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1989
 SOCSequestration_1989.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1989 SOCSequestration_1990.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1990
 SOCSequestration_1990.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1990 SOCSequestration_1991.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1991
 SOCSequestration_1991.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1991 SOCSequestration_1992.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1992
 SOCSequestration_1992.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1992 SOCSequestration_1993.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1993
 SOCSequestration_1993.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1993 SOCSequestration_1994.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1994
 SOCSequestration_1994.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1994 SOCSequestration_1995.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1995
 SOCSequestration_1995.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1995 SOCSequestration_1996.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1996
 SOCSequestration_1996.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1996 SOCSequestration_1997.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1997
 SOCSequestration_1997.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1997 SOCSequestration_1998.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1998
 SOCSequestration_1998.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1998 SOCSequestration_1999.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 1999
 SOCSequestration_1999.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 1999 SOCSequestration_2000.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2000
 SOCSequestration_2000.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2000 SOCSequestration_2001.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2001
 SOCSequestration_2001.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2001 SOCSequestration_2002.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2002
 SOCSequestration_2002.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2002 SOCSequestration_2003.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2003
 SOCSequestration_2003.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2003 SOCSequestration_2004.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2004
 SOCSequestration_2004.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2004 SOCSequestration_2005.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2005
 SOCSequestration_2005.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2005 SOCSequestration_2006.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2006
 SOCSequestration_2006.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2006 SOCSequestration_2007.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2007
 SOCSequestration_2007.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2007 SOCSequestration_2008.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2008
 SOCSequestration_2008.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2008 SOCSequestration_2009.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2009
 SOCSequestration_2009.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2009 SOCSequestration_2010.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2010
 SOCSequestration_2010.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2010 SOCSequestration_2011.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2011
 SOCSequestration_2011.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2011 SOCSequestration_2012.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2012
 SOCSequestration_2012.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2012 SOCSequestration_2013.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2013
 SOCSequestration_2013.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2013 SOCSequestration_2014.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2014
 SOCSequestration_2014.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2014 SOCSequestration_2015.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2015
 SOCSequestration_2015.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2015 SOCSequestration_2016.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2016
 SOCSequestration_2016.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2016 SOCSequestration_2017.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2017
 SOCSequestration_2017.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2017 SOCSequestration_2018.hdr: Header file
 of spatial map of soil organic carbon sequestration rate in 2018
 SOCSequestration_2018.bin: Binary file of spatial map of soil organic
 carbon sequestration rate in 2018 ##### (2) N2O emission N2O_1960.hdr:
 Header file of spatial map of N2O emission in 1960 N2O_1960.bin: Binary
 file of spatial map of N2O emission in 1960 N2O_1961.hdr: Header file of
 spatial map of N2O emission in 1961 N2O_1961.bin: Binary file of spatial
 map of N2O emission in 1961 N2O_1962.hdr: Header file of spatial map of
 N2O emission in 1962 N2O_1962.bin: Binary file of spatial map of N2O
 emission in 1962 N2O_1963.hdr: Header file of spatial map of N2O emission
 in 1963 N2O_1963.bin: Binary file of spatial map of N2O emission in 1963
 N2O_1964.hdr: Header file of spatial map of N2O emission in 1964
 N2O_1964.bin: Binary file of spatial map of N2O emission in 1964
 N2O_1965.hdr: Header file of spatial map of N2O emission in 1965
 N2O_1965.bin: Binary file of spatial map of N2O emission in 1965
 N2O_1966.hdr: Header file of spatial map of N2O emission in 1966
 N2O_1966.bin: Binary file of spatial map of N2O emission in 1966
 N2O_1967.hdr: Header file of spatial map of N2O emission in 1967
 N2O_1967.bin: Binary file of spatial map of N2O emission in 1967
 N2O_1968.hdr: Header file of spatial map of N2O emission in 1968
 N2O_1968.bin: Binary file of spatial map of N2O emission in 1968
 N2O_1969.hdr: Header file of spatial map of N2O emission in 1969
 N2O_1969.bin: Binary file of spatial map of N2O emission in 1969
 N2O_1970.hdr: Header file of spatial map of N2O emission in 1970
 N2O_1970.bin: Binary file of spatial map of N2O emission in 1970
 N2O_1971.hdr: Header file of spatial map of N2O emission in 1971
 N2O_1971.bin: Binary file of spatial map of N2O emission in 1971
 N2O_1972.hdr: Header file of spatial map of N2O emission in 1972
 N2O_1972.bin: Binary file of spatial map of N2O emission in 1972
 N2O_1973.hdr: Header file of spatial map of N2O emission in 1973
 N2O_1973.bin: Binary file of spatial map of N2O emission in 1973
 N2O_1974.hdr: Header file of spatial map of N2O emission in 1974
 N2O_1974.bin: Binary file of spatial map of N2O emission in 1974
 N2O_1975.hdr: Header file of spatial map of N2O emission in 1975
 N2O_1975.bin: Binary file of spatial map of N2O emission in 1975
 N2O_1976.hdr: Header file of spatial map of N2O emission in 1976
 N2O_1976.bin: Binary file of spatial map of N2O emission in 1976
 N2O_1977.hdr: Header file of spatial map of N2O emission in 1977
 N2O_1977.bin: Binary file of spatial map of N2O emission in 1977
 N2O_1978.hdr: Header file of spatial map of N2O emission in 1978
 N2O_1978.bin: Binary file of spatial map of N2O emission in 1978
 N2O_1979.hdr: Header file of spatial map of N2O emission in 1979
 N2O_1979.bin: Binary file of spatial map of N2O emission in 1979
 N2O_1980.hdr: Header file of spatial map of N2O emission in 1980
 N2O_1980.bin: Binary file of spatial map of N2O emission in 1980
 N2O_1981.hdr: Header file of spatial map of N2O emission in 1981
 N2O_1981.bin: Binary file of spatial map of N2O emission in 1981
 N2O_1982.hdr: Header file of spatial map of N2O emission in 1982
 N2O_1982.bin: Binary file of spatial map of N2O emission in 1982
 N2O_1983.hdr: Header file of spatial map of N2O emission in 1983
 N2O_1983.bin: Binary file of spatial map of N2O emission in 1983
 N2O_1984.hdr: Header file of spatial map of N2O emission in 1984
 N2O_1984.bin: Binary file of spatial map of N2O emission in 1984
 N2O_1985.hdr: Header file of spatial map of N2O emission in 1985
 N2O_1985.bin: Binary file of spatial map of N2O emission in 1985
 N2O_1986.hdr: Header file of spatial map of N2O emission in 1986
 N2O_1986.bin: Binary file of spatial map of N2O emission in 1986
 N2O_1987.hdr: Header file of spatial map of N2O emission in 1987
 N2O_1987.bin: Binary file of spatial map of N2O emission in 1987
 N2O_1988.hdr: Header file of spatial map of N2O emission in 1988
 N2O_1988.bin: Binary file of spatial map of N2O emission in 1988
 N2O_1989.hdr: Header file of spatial map of N2O emission in 1989
 N2O_1989.bin: Binary file of spatial map of N2O emission in 1989
 N2O_1990.hdr: Header file of spatial map of N2O emission in 1990
 N2O_1990.bin: Binary file of spatial map of N2O emission in 1990
 N2O_1991.hdr: Header file of spatial map of N2O emission in 1991
 N2O_1991.bin: Binary file of spatial map of N2O emission in 1991
 N2O_1992.hdr: Header file of spatial map of N2O emission in 1992
 N2O_1992.bin: Binary file of spatial map of N2O emission in 1992
 N2O_1993.hdr: Header file of spatial map of N2O emission in 1993
 N2O_1993.bin: Binary file of spatial map of N2O emission in 1993
 N2O_1994.hdr: Header file of spatial map of N2O emission in 1994
 N2O_1994.bin: Binary file of spatial map of N2O emission in 1994
 N2O_1995.hdr: Header file of spatial map of N2O emission in 1995
 N2O_1995.bin: Binary file of spatial map of N2O emission in 1995
 N2O_1996.hdr: Header file of spatial map of N2O emission in 1996
 N2O_1996.bin: Binary file of spatial map of N2O emission in 1996
 N2O_1997.hdr: Header file of spatial map of N2O emission in 1997
 N2O_1997.bin: Binary file of spatial map of N2O emission in 1997
 N2O_1998.hdr: Header file of spatial map of N2O emission in 1998
 N2O_1998.bin: Binary file of spatial map of N2O emission in 1998
 N2O_1999.hdr: Header file of spatial map of N2O emission in 1999
 N2O_1999.bin: Binary file of spatial map of N2O emission in 1999
 N2O_2000.hdr: Header file of spatial map of N2O emission in 2000
 N2O_2000.bin: Binary file of spatial map of N2O emission in 2000
 N2O_2001.hdr: Header file of spatial map of N2O emission in 2001
 N2O_2001.bin: Binary file of spatial map of N2O emission in 2001
 N2O_2002.hdr: Header file of spatial map of N2O emission in 2002
 N2O_2002.bin: Binary file of spatial map of N2O emission in 2002
 N2O_2003.hdr: Header file of spatial map of N2O emission in 2003
 N2O_2003.bin: Binary file of spatial map of N2O emission in 2003
 N2O_2004.hdr: Header file of spatial map of N2O emission in 2004
 N2O_2004.bin: Binary file of spatial map of N2O emission in 2004
 N2O_2005.hdr: Header file of spatial map of N2O emission in 2005
 N2O_2005.bin: Binary file of spatial map of N2O emission in 2005
 N2O_2006.hdr: Header file of spatial map of N2O emission in 2006
 N2O_2006.bin: Binary file of spatial map of N2O emission in 2006
 N2O_2007.hdr: Header file of spatial map of N2O emission in 2007
 N2O_2007.bin: Binary file of spatial map of N2O emission in 2007
 N2O_2008.hdr: Header file of spatial map of N2O emission in 2008
 N2O_2008.bin: Binary file of spatial map of N2O emission in 2008
 N2O_2009.hdr: Header file of spatial map of N2O emission in 2009
 N2O_2009.bin: Binary file of spatial map of N2O emission in 2009
 N2O_2010.hdr: Header file of spatial map of N2O emission in 2010
 N2O_2010.bin: Binary file of spatial map of N2O emission in 2010
 N2O_2011.hdr: Header file of spatial map of N2O emission in 2011
 N2O_2011.bin: Binary file of spatial map of N2O emission in 2011
 N2O_2012.hdr: Header file of spatial map of N2O emission in 2012
 N2O_2012.bin: Binary file of spatial map of N2O emission in 2012
 N2O_2013.hdr: Header file of spatial map of N2O emission in 2013
 N2O_2013.bin: Binary file of spatial map of N2O emission in 2013
 N2O_2014.hdr: Header file of spatial map of N2O emission in 2014
 N2O_2014.bin: Binary file of spatial map of N2O emission in 2014
 N2O_2015.hdr: Header file of spatial map of N2O emission in 2015
 N2O_2015.bin: Binary file of spatial map of N2O emission in 2015
 N2O_2016.hdr: Header file of spatial map of N2O emission in 2016
 N2O_2016.bin: Binary file of spatial map of N2O emission in 2016
 N2O_2017.hdr: Header file of spatial map of N2O emission in 2017
 N2O_2017.bin: Binary file of spatial map of N2O emission in 2017
 N2O_2018.hdr: Header file of spatial map of N2O emission in 2018
 N2O_2018.bin: Binary file of spatial map of N2O emission in 2018 ##### (3)
 CH4 emission CH4_1960.hdr: Header file of spatial map of CH4 emission in
 1960 CH4_1960.bin: Binary file of spatial map of CH4 emission in 1960
 CH4_1961.hdr: Header file of spatial map of CH4 emission in 1961
 CH4_1961.bin: Binary file of spatial map of CH4 emission in 1961
 CH4_1962.hdr: Header file of spatial map of CH4 emission in 1962
 CH4_1962.bin: Binary file of spatial map of CH4 emission in 1962
 CH4_1963.hdr: Header file of spatial map of CH4 emission in 1963
 CH4_1963.bin: Binary file of spatial map of CH4 emission in 1963
 CH4_1964.hdr: Header file of spatial map of CH4 emission in 1964
 CH4_1964.bin: Binary file of spatial map of CH4 emission in 1964
 CH4_1965.hdr: Header file of spatial map of CH4 emission in 1965
 CH4_1965.bin: Binary file of spatial map of CH4 emission in 1965
 CH4_1966.hdr: Header file of spatial map of CH4 emission in 1966
 CH4_1966.bin: Binary file of spatial map of CH4 emission in 1966
 CH4_1967.hdr: Header file of spatial map of CH4 emission in 1967
 CH4_1967.bin: Binary file of spatial map of CH4 emission in 1967
 CH4_1968.hdr: Header file of spatial map of CH4 emission in 1968
 CH4_1968.bin: Binary file of spatial map of CH4 emission in 1968
 CH4_1969.hdr: Header file of spatial map of CH4 emission in 1969
 CH4_1969.bin: Binary file of spatial map of CH4 emission in 1969
 CH4_1970.hdr: Header file of spatial map of CH4 emission in 1970
 CH4_1970.bin: Binary file of spatial map of CH4 emission in 1970
 CH4_1971.hdr: Header file of spatial map of CH4 emission in 1971
 CH4_1971.bin: Binary file of spatial map of CH4 emission in 1971
 CH4_1972.hdr: Header file of spatial map of CH4 emission in 1972
 CH4_1972.bin: Binary file of spatial map of CH4 emission in 1972
 CH4_1973.hdr: Header file of spatial map of CH4 emission in 1973
 CH4_1973.bin: Binary file of spatial map of CH4 emission in 1973
 CH4_1974.hdr: Header file of spatial map of CH4 emission in 1974
 CH4_1974.bin: Binary file of spatial map of CH4 emission in 1974
 CH4_1975.hdr: Header file of spatial map of CH4 emission in 1975
 CH4_1975.bin: Binary file of spatial map of CH4 emission in 1975
 CH4_1976.hdr: Header file of spatial map of CH4 emission in 1976
 CH4_1976.bin: Binary file of spatial map of CH4 emission in 1976
 CH4_1977.hdr: Header file of spatial map of CH4 emission in 1977
 CH4_1977.bin: Binary file of spatial map of CH4 emission in 1977
 CH4_1978.hdr: Header file of spatial map of CH4 emission in 1978
 CH4_1978.bin: Binary file of spatial map of CH4 emission in 1978
 CH4_1979.hdr: Header file of spatial map of CH4 emission in 1979
 CH4_1979.bin: Binary file of spatial map of CH4 emission in 1979
 CH4_1980.hdr: Header file of spatial map of CH4 emission in 1980
 CH4_1980.bin: Binary file of spatial map of CH4 emission in 1980
 CH4_1981.hdr: Header file of spatial map of CH4 emission in 1981
 CH4_1981.bin: Binary file of spatial map of CH4 emission in 1981
 CH4_1982.hdr: Header file of spatial map of CH4 emission in 1982
 CH4_1982.bin: Binary file of spatial map of CH4 emission in 1982
 CH4_1983.hdr: Header file of spatial map of CH4 emission in 1983
 CH4_1983.bin: Binary file of spatial map of CH4 emission in 1983
 CH4_1984.hdr: Header file of spatial map of CH4 emission in 1984
 CH4_1984.bin: Binary file of spatial map of CH4 emission in 1984
 CH4_1985.hdr: Header file of spatial map of CH4 emission in 1985
 CH4_1985.bin: Binary file of spatial map of CH4 emission in 1985
 CH4_1986.hdr: Header file of spatial map of CH4 emission in 1986
 CH4_1986.bin: Binary file of spatial map of CH4 emission in 1986
 CH4_1987.hdr: Header file of spatial map of CH4 emission in 1987
 CH4_1987.bin: Binary file of spatial map of CH4 emission in 1987
 CH4_1988.hdr: Header file of spatial map of CH4 emission in 1988
 CH4_1988.bin: Binary file of spatial map of CH4 emission in 1988
 CH4_1989.hdr: Header file of spatial map of CH4 emission in 1989
 CH4_1989.bin: Binary file of spatial map of CH4 emission in 1989
 CH4_1990.hdr: Header file of spatial map of CH4 emission in 1990
 CH4_1990.bin: Binary file of spatial map of CH4 emission in 1990
 CH4_1991.hdr: Header file of spatial map of CH4 emission in 1991
 CH4_1991.bin: Binary file of spatial map of CH4 emission in 1991
 CH4_1992.hdr: Header file of spatial map of CH4 emission in 1992
 CH4_1992.bin: Binary file of spatial map of CH4 emission in 1992
 CH4_1993.hdr: Header file of spatial map of CH4 emission in 1993
 CH4_1993.bin: Binary file of spatial map of CH4 emission in 1993
 CH4_1994.hdr: Header file of spatial map of CH4 emission in 1994
 CH4_1994.bin: Binary file of spatial map of CH4 emission in 1994
 CH4_1995.hdr: Header file of spatial map of CH4 emission in 1995
 CH4_1995.bin: Binary file of spatial map of CH4 emission in 1995
 CH4_1996.hdr: Header file of spatial map of CH4 emission in 1996
 CH4_1996.bin: Binary file of spatial map of CH4 emission in 1996
 CH4_1997.hdr: Header file of spatial map of CH4 emission in 1997
 CH4_1997.bin: Binary file of spatial map of CH4 emission in 1997
 CH4_1998.hdr: Header file of spatial map of CH4 emission in 1998
 CH4_1998.bin: Binary file of spatial map of CH4 emission in 1998
 CH4_1999.hdr: Header file of spatial map of CH4 emission in 1999
 CH4_1999.bin: Binary file of spatial map of CH4 emission in 1999
 CH4_2000.hdr: Header file of spatial map of CH4 emission in 2000
 CH4_2000.bin: Binary file of spatial map of CH4 emission in 2000
 CH4_2001.hdr: Header file of spatial map of CH4 emission in 2001
 CH4_2001.bin: Binary file of spatial map of CH4 emission in 2001
 CH4_2002.hdr: Header file of spatial map of CH4 emission in 2002
 CH4_2002.bin: Binary file of spatial map of CH4 emission in 2002
 CH4_2003.hdr: Header file of spatial map of CH4 emission in 2003
 CH4_2003.bin: Binary file of spatial map of CH4 emission in 2003
 CH4_2004.hdr: Header file of spatial map of CH4 emission in 2004
 CH4_2004.bin: Binary file of spatial map of CH4 emission in 2004
 CH4_2005.hdr: Header file of spatial map of CH4 emission in 2005
 CH4_2005.bin: Binary file of spatial map of CH4 emission in 2005
 CH4_2006.hdr: Header file of spatial map of CH4 emission in 2006
 CH4_2006.bin: Binary file of spatial map of CH4 emission in 2006
 CH4_2007.hdr: Header file of spatial map of CH4 emission in 2007
 CH4_2007.bin: Binary file of spatial map of CH4 emission in 2007
 CH4_2008.hdr: Header file of spatial map of CH4 emission in 2008
 CH4_2008.bin: Binary file of spatial map of CH4 emission in 2008
 CH4_2009.hdr: Header file of spatial map of CH4 emission in 2009
 CH4_2009.bin: Binary file of spatial map of CH4 emission in 2009
 CH4_2010.hdr: Header file of spatial map of CH4 emission in 2010
 CH4_2010.bin: Binary file of spatial map of CH4 emission in 2010
 CH4_2011.hdr: Header file of spatial map of CH4 emission in 2011
 CH4_2011.bin: Binary file of spatial map of CH4 emission in 2011
 CH4_2012.hdr: Header file of spatial map of CH4 emission in 2012
 CH4_2012.bin: Binary file of spatial map of CH4 emission in 2012
 CH4_2013.hdr: Header file of spatial map of CH4 emission in 2013
 CH4_2013.bin: Binary file of spatial map of CH4 emission in 2013
 CH4_2014.hdr: Header file of spatial map of CH4 emission in 2014
 CH4_2014.bin: Binary file of spatial map of CH4 emission in 2014
 CH4_2015.hdr: Header file of spatial map of CH4 emission in 2015
 CH4_2015.bin: Binary file of spatial map of CH4 emission in 2015
 CH4_2016.hdr: Header file of spatial map of CH4 emission in 2016
 CH4_2016.bin: Binary file of spatial map of CH4 emission in 2016
 CH4_2017.hdr: Header file of spatial map of CH4 emission in 2017
 CH4_2017.bin: Binary file of spatial map of CH4 emission in 2017
 CH4_2018.hdr: Header file of spatial map of CH4 emission in 2018
 CH4_2018.bin: Binary file of spatial map of CH4 emission in 2018