300
320
340
360
380
400
420
1958
1968
1978
Full record ending at February 10, 2019
1988
1998
2008
2018
CO
2 mole fraction / ppm
Time/yr
Carbon Dioxide Concentrations at Mauna Loa Observatory
a
b
1550
1600
1650
1700
1750
1800
1850
1900
1979
1984
1989
1994
1999
2004
2009
2014
CH
4 mole fraction / ppb
Time / yr
Annually Mean Methane Concentrations (1979-2017)
Air Pollution and Climate Change: Sustainability, Restoration, and Ethical Implications, Fig. 4 (continued)
Air Pollution and Climate Change: Sustainability, Restoration, and Ethical Implications
287