Global mean CH4 concentration (ppb)
-----------------------------------
 Year     monthly
------------------
1983.542  1625.5
1983.625  1625.9
1983.708  1636.2
1983.792  1644.6
1983.875  1643.0
1983.958  1639.6
1984.042  1638.7
1984.125  1638.1
1984.208  1639.5
1984.292  1643.3
1984.375  1643.2
1984.458  1639.7
1984.542  1637.8
1984.625  1640.6
1984.708  1649.3
1984.792  1654.5
1984.875  1653.7
1984.958  1656.0
1985.042  1656.4
1985.125  1652.7
1985.208  1654.1
1985.292  1657.9
1985.375  1656.3
1985.458  1650.3
1985.542  1646.2
1985.625  1651.0
1985.708  1661.8
1985.792  1667.6
1985.875  1667.0
1985.958  1666.2
1986.042  1666.5
1986.125  1667.0
1986.208  1669.2
1986.292  1670.8
1986.375  1668.5
1986.458  1664.9
1986.542  1662.3
1986.625  1663.4
1986.708  1670.9
1986.792  1678.0
1986.875  1678.8
1986.958  1677.9
1987.042  1677.1
1987.125  1676.7
1987.208  1678.5
1987.292  1680.8
1987.375  1681.8
1987.458  1680.3
1987.542  1676.1
1987.625  1676.3
1987.708  1684.0
1987.792  1690.7
1987.875  1691.3
1987.958  1690.3
1988.042  1690.4
1988.125  1690.8
1988.208  1691.0
1988.292  1690.5
1988.375  1689.8
1988.458  1688.0
1988.542  1686.2
1988.625  1689.1
1988.708  1695.9
1988.792  1701.5
1988.875  1703.1
1988.958  1702.2
1989.042  1699.9
1989.125  1699.8
1989.208  1701.5
1989.292  1703.3
1989.375  1703.7
1989.458  1700.9
1989.542  1698.3
1989.625  1701.4
1989.708  1706.8
1989.792  1710.4
1989.875  1712.4
1989.958  1712.1
1990.042  1711.2
1990.125  1712.4
1990.208  1713.3
1990.292  1712.5
1990.375  1711.0
1990.458  1708.5
1990.542  1706.0
1990.625  1708.9
1990.708  1716.5
1990.792  1721.6
1990.875  1723.2
1990.958  1723.0
1991.042  1720.9
1991.125  1720.5
1991.208  1721.3
1991.292  1722.2
1991.375  1722.7
1991.458  1719.7
1991.542  1715.8
1991.625  1718.0
1991.708  1725.0
1991.792  1732.3
1991.875  1737.4
1991.958  1739.9
1992.042  1739.4
1992.125  1737.3
1992.208  1736.2
1992.292  1736.3
1992.375  1735.5
1992.458  1732.3
1992.542  1728.8
1992.625  1729.4
1992.708  1733.3
1992.792  1737.3
1992.875  1739.5
1992.958  1738.9
1993.042  1735.5
1993.125  1734.0
1993.208  1735.3
1993.292  1736.7
1993.375  1734.9
1993.458  1730.9
1993.542  1728.1
1993.625  1730.5
1993.708  1737.4
1993.792  1742.8
1993.875  1745.3
1993.958  1744.7
1994.042  1741.1
1994.125  1740.4
1994.208  1741.7
1994.292  1742.0
1994.375  1740.8
1994.458  1737.2
1994.542  1732.4
1994.625  1733.2
1994.708  1741.5
1994.792  1749.3
1994.875  1751.3
1994.958  1751.2
1995.042  1751.0
1995.125  1749.7
1995.208  1749.1
1995.292  1749.2
1995.375  1747.5
1995.458  1742.8
1995.542  1739.7
1995.625  1742.7
1995.708  1748.9
1995.792  1753.9
1995.875  1755.5
1995.958  1753.9
1996.042  1752.3
1996.125  1753.3
1996.208  1752.6
1996.292  1749.6
1996.375  1748.0
1996.458  1746.2
1996.542  1742.3
1996.625  1743.1
1996.708  1751.2
1996.792  1759.0
1996.875  1760.2
1996.958  1757.1
1997.042  1753.1
1997.125  1753.7
1997.208  1755.2
1997.292  1755.0
1997.375  1753.6
1997.458  1750.1
1997.542  1746.1
1997.625  1747.5
1997.708  1754.5
1997.792  1760.1
1997.875  1761.9
1997.958  1761.7
1998.042  1761.0
1998.125  1761.2
1998.208  1762.5
1998.292  1764.4
1998.375  1764.4
1998.458  1760.7
1998.542  1756.3
1998.625  1759.3
1998.708  1769.4
1998.792  1775.7
1998.875  1775.6
1998.958  1774.1
1999.042  1773.7
1999.125  1773.5
1999.208  1774.0
1999.292  1774.6
1999.375  1772.5
1999.458  1767.2
1999.542  1762.9
1999.625  1764.2
1999.708  1770.1
1999.792  1776.0
1999.875  1777.9
1999.958  1776.8
2000.042  1775.4
2000.125  1775.1
2000.208  1775.7
2000.292  1776.7
2000.375  1774.8
2000.458  1768.5
2000.542  1763.4
2000.625  1765.1
2000.708  1771.6
2000.792  1777.2
2000.875  1777.7
2000.958  1775.3
2001.042  1772.5
2001.125  1772.2
2001.208  1773.3
2001.292  1773.9
2001.375  1771.0
2001.458  1765.9
2001.542  1762.6
2001.625  1763.7
2001.708  1769.5
2001.792  1775.1
2001.875  1776.7
2001.958  1775.8
2002.042  1773.7
2002.125  1772.6
2002.208  1773.2
2002.292  1772.7
2002.375  1770.4
2002.458  1766.9
2002.542  1764.2
2002.625  1766.6
2002.708  1773.2
2002.792  1778.1
2002.875  1779.5
2002.958  1779.4
2003.042  1777.4
2003.125  1774.6
2003.208  1773.8
2003.292  1774.5
2003.375  1774.1
2003.458  1771.5
2003.542  1770.5
2003.625  1774.1
2003.708  1780.1
2003.792  1784.1
2003.875  1784.7
2003.958  1783.2
2004.042  1780.4
2004.125  1779.5
2004.208  1780.5
2004.292  1780.5
2004.375  1777.7
2004.458  1772.6
2004.542  1767.9
2004.625  1769.5
2004.708  1775.8
2004.792  1779.9
2004.875  1780.2
2004.958  1778.3
2005.042  1775.5
2005.125  1775.0
2005.208  1775.3
2005.292  1774.7
2005.375  1772.4
2005.458  1768.9
2005.542  1766.4
2005.625  1767.8
2005.708  1772.5
2005.792  1777.8
2005.875  1780.9
2005.958  1780.0
2006.042  1778.8
2006.125  1778.8
2006.208  1777.0
2006.292  1775.9
2006.375  1775.2
2006.458  1769.7
2006.542  1764.2
2006.625  1766.6
2006.708  1773.9
2006.792  1777.8
2006.875  1778.5
2006.958  1779.4
2007.042  1779.1
2007.125  1778.2
2007.208  1779.5
2007.292  1781.1
2007.375  1779.9
2007.458  1775.6
2007.542  1771.6
2007.625  1775.4
2007.708  1784.3
2007.792  1789.1
2007.875  1789.5
2007.958  1788.5
2008.042  1786.8
2008.125  1785.6
2008.208  1785.6
2008.292  1786.5
2008.375  1785.6
2008.458  1780.9
2008.542  1777.3
2008.625  1780.1
2008.708  1786.6
2008.792  1793.8
2008.875  1797.7
2008.958  1796.6
2009.042  1794.4
2009.125  1795.2
2009.208  1795.6
2009.292  1795.1
2009.375  1792.3
2009.458  1786.9
2009.542  1784.4
2009.625  1787.8
2009.708  1794.1
2009.792  1798.1
2009.875  1797.8
2009.958  1796.2
2010.042  1797.3
2010.125  1798.9
2010.208  1798.6
2010.292  1798.9
2010.375  1797.7
2010.458  1792.5
2010.542  1789.1
2010.625  1793.0
2010.708  1800.8
2010.792  1806.1
2010.875  1807.0
2010.958  1804.0
2011.042  1801.0
2011.125  1799.7
2011.208  1799.4
2011.292  1801.7
2011.375  1803.1
2011.458  1799.1
2011.542  1795.8
2011.625  1798.9
2011.708  1804.3
2011.792  1809.7
2011.875  1812.4
2011.958  1810.5
2012.042  1808.4
2012.125  1809.3
2012.208  1810.1
2012.292  1808.5
2012.375  1804.8
2012.458  1800.9
2012.542  1799.0
2012.625  1802.5
2012.708  1809.6
2012.792  1815.1
2012.875  1816.2
2012.958  1814.5
2013.042  1813.5
2013.125  1813.7
2013.208  1813.1
2013.292  1812.8
2013.375  1812.2
2013.458  1808.9
2013.542  1805.9
2013.625  1807.8
2013.708  1813.4
2013.792  1818.3
2013.875  1820.6
2013.958  1819.6
2014.042  1816.7
2014.125  1816.3
2014.208  1817.8
2014.292  1820.7
2014.375  1822.1
2014.458  1818.6
2014.542  1815.4
2014.625  1819.0
2014.708  1826.1
2014.792  1831.1
2014.875  1833.0
2014.958  1833.2
2015.042  1832.5
2015.125  1832.1
2015.208  1832.4
2015.292  1833.1
2015.375  1832.1
2015.458  1827.6
2015.542  1824.4
2015.625  1828.2
2015.708  1835.5
2015.792  1840.8
2015.875  1844.2
2015.958  1844.8
2016.042  1842.1
2016.125  1841.1
2016.208  1842.3
2016.292  1843.2
2016.375  1841.9
2016.458  1837.8
2016.542  1834.0
2016.625  1835.8
2016.708  1843.2
2016.792  1849.7
2016.875  1851.0
2016.958  1851.0
2017.042  1850.7
2017.125  1849.2
2017.208  1848.1
2017.292  1848.5
2017.375  1847.8
2017.458  1844.1
2017.542  1841.5
------------------