Mauna Loa CO₂

June 2021

Mauna Loa Observatory (MLO)  |  Atmospheric CO₂
monthly mean concentrations  |  ppm = parts per million
 

Two independent records of CO₂ changes are maintained in parallel at Mauna Loa.   A graph showing the two records together is available at the bottom of the Scripps CO₂ Program website.  All-time monthly record highs for CO₂ are recorded at the CO₂ Records webpage. 

Use the tabs below to view the latest monthly CO₂ data, charts and related links.

 Mauna Loa CO₂

June 2021

	NOAA-GML	SCRIPPS UCSD
June 2021	418.94 ppm	418.73 ppm
June 2020	416.60 ppm	416.23 ppm
June 2019	414.16 ppm	413.89 ppm
Last Update:	July 6, 2021	July 2, 2021
View Data:	NOAA	Scripps

Mauna Loa Observatory (MLO)  |  Atmospheric CO₂
monthly mean concentrations  |  ppm = parts per million
 

Two independent records of CO₂ changes are maintained in parallel at Mauna Loa.   A graph showing the two records together is available at the bottom of the Scripps CO₂ Program website.  All-time monthly record highs for CO₂ are recorded at the CO₂ Records webpage. 

Use the tabs below to view the latest monthly CO₂ data, charts and related links.

 

NOAA

NOAA Monthly Data

 

NOAA Monthly CO₂ Data

Atmospheric CO₂  |  March 1958 to Present  |  Mauna Loa Observatory

NOAA-ESRL update: September 5, 2018

Year	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
2018	407.98	408.35	409.46	410.26	411.24	410.79	408.71	406.99	0.00	0.00	0.00	0.00
2017	406.13	406.42	407.18	409.00	409.65	408.84	407.07	405.07	403.38	403.64	405.14	406.82
2016	402.52	404.04	404.83	407.42	407.70	406.81	404.39	402.25	401.03	401.57	403.53	404.42
2015	399.98	400.28	401.54	403.28	403.96	402.80	401.31	398.93	397.63	398.29	400.16	401.85
2014	397.85	398.01	399.77	401.38	401.78	401.25	399.10	397.03	395.38	396.03	397.28	398.91
2013	395.55	396.80	397.43	398.41	399.78	398.61	397.32	395.20	393.45	393.70	395.16	396.84
2012	393.12	393.86	394.40	396.18	396.74	395.71	394.36	392.39	391.11	391.05	392.98	394.34
2011	391.33	391.86	392.60	393.25	394.19	393.73	392.51	390.13	389.08	389.00	390.28	391.86
2010	388.71	390.20	391.17	392.46	393.00	392.15	390.20	388.35	386.85	387.24	388.67	389.79
2009	386.94	387.48	388.82	389.55	390.14	389.48	388.03	386.11	384.74	384.43	386.02	387.42
2008	385.52	385.82	386.03	387.21	388.54	387.76	386.36	384.09	383.18	382.99	384.19	385.56
2007	382.89	383.90	384.58	386.50	386.56	386.10	384.50	381.99	380.96	381.12	382.45	383.95
2006	381.38	382.19	382.67	384.61	385.03	384.05	382.46	380.41	378.85	379.13	380.15	381.82
2005	378.46	379.73	380.77	382.29	382.45	382.21	380.74	378.74	376.70	377.00	378.35	380.11
2004	377.00	377.87	378.88	380.35	380.62	379.69	377.47	376.01	374.25	374.46	376.16	377.51
2003	374.88	375.64	376.45	377.73	378.60	378.28	376.70	374.38	373.17	373.14	374.66	375.99
2002	372.53	373.20	374.12	375.02	375.76	375.52	374.01	371.85	370.75	370.55	372.25	373.79
2001	370.59	371.51	372.43	373.37	373.85	373.21	371.51	369.61	368.18	368.45	369.76	371.24
2000	369.29	369.54	370.60	371.82	371.58	371.70	369.86	368.13	367.00	367.03	368.37	369.67
1999	368.18	369.07	369.68	370.99	370.96	370.30	369.45	366.90	364.81	365.37	366.72	368.10
1998	365.26	365.98	367.24	368.66	369.42	368.99	367.82	365.95	364.02	364.40	365.52	367.13
1997	363.09	364.03	364.51	366.35	366.64	365.59	364.31	362.25	360.29	360.82	362.49	364.38
1996	362.07	363.24	364.17	364.57	365.13	364.92	363.55	361.38	359.54	359.58	360.89	362.24
1995	359.92	360.86	361.83	363.30	363.69	363.19	361.64	359.12	358.17	357.99	359.45	360.68
1994	358.24	358.92	359.99	361.23	361.65	360.81	359.38	357.46	355.73	356.07	357.53	358.98
1993	357.00	357.31	358.47	359.27	360.19	359.52	357.33	355.64	354.03	354.12	355.41	356.91
1992	356.25	357.11	357.86	359.09	359.59	359.33	357.01	354.94	352.96	353.32	354.32	355.57
1991	354.84	355.73	357.23	358.66	359.13	358.13	356.19	353.85	352.25	352.35	353.81	355.12
1990	353.80	355.04	355.73	356.32	357.32	356.34	354.84	353.01	351.31	351.62	353.07	354.33
1989	352.91	353.27	353.96	355.64	355.86	355.37	353.99	351.81	350.05	350.25	351.49	352.85
1988	350.39	351.64	352.41	353.69	354.21	353.72	352.69	350.40	348.92	349.13	350.20	351.41
1987	348.52	348.73	349.73	351.31	352.09	351.53	350.11	348.08	346.52	346.59	347.96	349.16
1986	346.56	347.28	348.01	349.77	350.38	349.93	348.16	346.08	345.22	344.51	345.93	347.22
1985	345.21	346.16	347.74	348.34	349.06	348.38	346.72	345.02	343.27	343.13	344.49	345.88
1984	344.10	344.79	345.52	346.84	347.63	346.97	345.53	343.55	341.40	341.67	343.10	344.70
1983	341.68	342.90	343.33	345.25	346.03	345.63	344.19	342.27	340.35	340.38	341.59	343.05
1982	340.96	341.73	342.81	343.97	344.63	343.79	342.32	340.09	338.28	338.29	339.60	340.90
1981	339.29	340.55	341.61	342.53	343.03	342.54	340.78	338.44	336.95	337.08	338.58	339.88
1980	337.90	338.34	340.01	340.93	341.48	341.33	339.40	337.70	336.19	336.15	337.27	338.32
1979	336.14	336.69	338.27	338.95	339.21	339.26	337.54	335.75	333.98	334.19	335.31	336.81
1978	334.95	335.25	336.66	337.69	338.03	338.01	336.41	334.41	332.37	332.41	333.75	334.90
1977	332.66	333.13	334.95	336.13	336.93	336.17	334.88	332.56	331.29	331.27	332.41	333.60
1976	331.59	332.75	333.52	334.64	334.77	334.00	333.06	330.68	328.95	328.75	330.15	331.62
1975	330.73	331.46	331.90	333.17	333.94	333.45	331.98	329.95	328.50	328.35	329.37	330.59
1974	329.35	330.71	331.48	332.65	333.20	332.16	331.07	329.12	327.32	327.28	328.30	329.58
1973	328.54	329.56	330.30	331.50	332.48	332.07	330.87	329.31	327.51	327.18	328.16	328.64
1972	326.77	327.63	327.75	329.72	330.07	329.09	328.05	326.32	324.93	325.06	326.50	327.55
1971	326.17	326.68	327.18	327.78	328.92	328.57	327.34	325.46	323.36	323.57	324.80	326.01
1970	325.03	325.99	326.87	328.13	328.07	327.66	326.35	324.69	323.10	323.16	323.98	325.13
1969	324.00	324.42	325.64	326.66	327.34	326.76	325.88	323.67	322.38	321.78	322.85	324.11
1968	322.57	323.15	323.89	325.02	325.57	325.36	324.14	322.03	320.41	320.25	321.31	322.84
1967	322.07	322.50	323.04	324.42	325.00	324.09	322.55	320.92	319.31	319.31	320.72	321.96
1966	320.62	321.59	322.39	323.87	324.01	323.75	322.39	320.37	318.64	318.10	319.79	321.08
1965	319.44	320.44	320.89	322.13	322.16	321.87	321.39	318.81	317.81	317.30	318.87	319.42
1964	319.57	320.07	320.73	321.77	322.25	321.89	320.44	318.70	316.70	316.79	317.79	318.71
1963	318.74	319.08	319.86	321.39	322.25	321.47	319.74	317.77	316.21	315.99	317.12	318.31
1962	317.94	318.56	319.68	320.63	321.01	320.55	319.58	317.40	316.26	315.42	316.69	317.69
1961	316.93	317.70	318.54	319.48	320.58	319.77	318.57	316.79	314.80	315.38	316.10	317.01
1960	316.43	316.97	317.58	319.02	320.03	319.59	318.18	315.91	314.16	313.83	315.00	316.19
1959	315.62	316.38	316.71	317.72	318.29	318.15	316.54	314.80	313.84	313.26	314.80	315.58
1958			315.71	317.45	317.50	317.10	315.86	314.93	313.20	312.66	313.33	314.67

units = parts per million (ppm)

Scripps data: 1958 - 1974  |  NOAA data: 1974 - Present
Source Dataset  NOAA-ESRL Global Monitoring [Web + .txt]

Table produced by CO₂.Earth

 

Scripps

Scripps Monthly Data

 

 Scripps Monthly CO₂ Data

Atmospheric CO₂  |  March 1958 to Present  |  Mauna Loa Observatory

Scripps UCSD Update: November 10, 2017

Year	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
2017	406.07	406.64	407.06	408.95	409.91	409.12	407.20	405.24	403.27	403.64
2016	402.65	404.16	404.86	407.57	407.65	407.00	404.50	402.24	401.01	401.50	403.64	404.55
2015	399.85	400.31	401.51	403.45	404.11	402.88	401.60	399.00	397.50	398.28	400.24	401.89
2014	397.93	398.10	399.47	401.33	401.88	401.31	399.07	397.21	395.40	395.65	397.22	398.79
2013	395.61	396.85	397.26	398.35	399.98	398.87	397.37	395.41	393.39	393.70	395.19	396.82
2012	393.07	393.35	394.36	396.43	396.87	395.88	394.52	392.54	391.13	391.01	392.95	394.34
2011	391.30	391.92	392.45	393.37	394.28	393.69	392.60	390.21	389.00	388.93	390.24	391.80
2010	388.55	390.07	391.01	392.38	393.22	392.24	390.33	388.52	386.84	387.16	388.67	389.81
2009	386.65	387.12	388.51	389.57	390.16	389.62	388.07	386.08	384.65	384.33	386.05	387.49
2008	385.07	385.84	385.83	386.77	388.51	388.05	386.25	384.08	383.09	382.78	384.01	385.11
2007	382.58	383.71	384.34	386.23	386.41	385.87	384.45	381.84	380.86	380.86	382.35	383.61
2006	381.37	382.02	382.56	384.37	384.92	384.03	382.28	380.48	378.81	379.06	380.14	381.66
2005	378.34	379.61	380.17	382.05	382.24	382.08	380.67	378.67	376.42	376.80	378.31	379.96
2004	376.79	377.36	378.39	380.50	380.61	379.55	377.76	375.84	374.05	374.22	375.84	377.44
2003	374.68	375.62	376.11	377.65	378.35	378.13	376.61	374.48	372.98	373.00	374.34	375.69
2002	372.44	373.08	373.52	374.86	375.55	375.40	374.02	371.48	370.70	370.25	372.08	373.78
2001	370.28	371.50	372.12	372.87	374.02	373.31	371.62	369.55	367.96	368.10	369.68	371.24
2000	369.14	369.46	370.51	371.66	371.83	371.69	370.12	368.12	366.62	366.73	368.29	369.53
1999	368.15	368.87	369.59	371.14	371.00	370.35	369.27	366.93	364.64	365.13	366.68	368.01
1998	365.33	366.15	367.31	368.61	369.30	368.88	367.64	365.77	363.90	364.24	365.46	366.97
1997	363.18	363.99	364.56	366.36	366.80	365.63	364.47	362.50	360.19	360.77	362.43	364.28
1996	362.05	363.24	364.02	364.72	365.41	364.97	363.65	361.48	359.45	359.61	360.76	362.33
1995	359.97	361.00	361.64	363.45	363.80	363.26	361.90	359.45	358.05	357.76	359.56	360.70
1994	358.37	358.91	359.97	361.27	361.69	360.94	359.55	357.48	355.84	356.00	357.58	359.04
1993	356.70	357.16	358.38	359.46	360.28	359.60	357.57	355.52	353.69	353.99	355.33	356.80
1992	355.99	356.72	357.81	359.15	359.66	359.25	357.02	355.00	353.01	353.31	354.16	355.40
1991	354.72	355.75	357.16	358.60	359.34	358.24	356.17	354.02	352.15	352.21	353.75	354.99
1990	353.66	354.70	355.38	356.20	357.16	356.23	354.81	352.91	350.96	351.18	352.83	354.21
1989	352.76	353.07	353.68	355.42	355.67	355.12	353.90	351.67	349.80	349.99	351.29	352.52
1988	350.43	351.73	352.22	353.59	354.22	353.79	352.38	350.43	348.73	348.88	350.07	351.34
1987	348.02	348.47	349.41	350.99	351.85	351.26	349.51	348.10	346.45	346.36	347.81	348.96
1986	346.30	346.95	347.85	349.55	350.21	349.55	347.94	345.90	344.85	344.17	345.66	346.90
1985	344.97	345.99	347.43	348.35	348.93	348.25	346.56	344.68	343.09	342.80	344.24	345.56
1984	343.70	344.50	345.28	347.07	347.43	346.80	345.39	343.28	341.07	341.35	342.98	344.22
1983	341.38	342.52	343.10	344.94	345.76	345.32	343.98	342.38	339.87	339.99	341.15	342.99
1982	340.75	341.61	342.70	343.57	344.14	343.35	342.06	339.81	337.98	337.86	339.26	340.49
1981	339.24	340.48	341.38	342.51	342.91	342.25	340.49	338.43	336.69	336.86	338.36	339.61
1980	338.01	338.36	340.07	340.77	341.47	341.17	339.56	337.60	335.88	336.02	337.10	338.21
1979	336.23	336.76	337.96	338.89	339.47	339.29	337.73	336.08	333.92	333.86	335.29	336.73
1978	334.97	335.38	336.64	337.76	338.01	337.89	336.54	334.68	332.76	332.55	333.92	334.95
1977	332.93	333.42	334.70	336.07	336.75	336.27	334.92	332.75	331.59	331.16	332.40	333.85
1976	331.75	332.56	333.50	334.58	334.88	334.34	333.05	330.94	329.30	328.94	330.31	331.68
1975	330.40	331.40	332.04	333.31	333.97	333.60	331.90	330.06	328.56	328.34	329.49	330.76
1974	329.35	330.71	331.48	332.65	333.09	332.25	331.18	329.39	327.43	327.37	328.46	329.57
1973	328.55	329.56	330.30	331.50	332.48	332.07	330.87	329.31	327.51	327.18	328.16	328.64
1972	326.77	327.63	327.75	329.73	330.07	329.09	328.04	326.32	324.84	325.20	326.50	327.55
1971	326.17	326.68	327.17	327.79	328.92	328.57	327.36	325.43	323.36	323.57	324.80	326.01
1970	325.06	325.98	326.93	328.14	328.08	327.67	326.34	324.69	323.10	323.07	324.01	325.13
1969	324.00	324.42	325.63	326.66	327.38	326.70	325.88	323.66	322.38	321.78	322.85	324.12
1968	322.57	323.14	323.89	325.02	325.57	325.36	324.14	322.11	320.33	320.25	321.32	322.89
1967	322.32	322.50	323.04	324.42	325.00	324.09	322.55	320.92	319.25	319.39	320.72	321.96
1966	320.62	321.59	322.39	323.70	324.08	323.75	322.39	320.36	318.64	318.10	319.79	321.03
1965	319.44	320.44	320.89	322.14	322.16	321.87	321.21	318.87	317.82	317.30	318.87	319.42
1964	319.57	319.98	320.75	321.84	322.26	321.89	320.44	318.69	316.71	316.87	317.68	318.71
1963	318.74	319.07	319.86	321.39	322.25	321.48	319.74	317.77	316.21	315.99	317.06	318.35
1962	317.94	318.55	319.68	320.57	321.01	320.62	319.61	317.40	316.25	315.42	316.69	317.70
1961	316.90	317.70	318.54	319.48	320.58	319.77	318.57	316.79	314.99	315.31	316.10	317.01
1960	316.43	316.97	317.58	319.03	320.03	319.59	318.18	315.90	314.17	313.83	315.00	316.19
1959	315.58	316.48	316.65	317.72	318.29	318.15	316.54	314.80	313.84	313.34	314.81	315.58
1958			315.69	317.45	317.50	317.22	315.86	314.93	313.21	312.45	313.33	314.67

units = parts per million (ppm)

Scripps Institution of Oceanography  |  University of California San Diego
Source Dataset  Scripps CO₂ Program [Web + CSV Spreadsheet + Twitter)

Table produced by CO₂.Earth

 

 

 

Global

Global Monthly CO₂ Data

 

 

Global Monthly CO₂ Averages

April 2020

April 2021	416.17 ppm
April 2020	413.86 ppm
April 2019	410.53 ppm
Last Update:	July 6, 2021
View Data:	NOAA global monthly data NOAA global trends web

Atmospheric CO₂
monthly mean concentrations  |  ppm = parts per million
NOAA-ESRL-GMD CCGG global cooperative air sampling network

NOAA-ESRL’s Global Monitoring Division (GMD) operates the largest and most comprehensive global network of air sampling sites.  In the 1970s, the GMD started air sampling programs at Mauna Loa and other sites around the world.  GMD network coordination activities are based in Boulder, Colorado, USA.  

NOAA publishes a monthly global average based on CO2 measurements by its distributed network of air sampling sites.  Global averages have usually been posted a month after Mauna Loa averages are posted.  For example, the Mauna Loa average for January has often been published in the first half of February, and the global average for January has often been published in the first half of March.

Despite seasonal variations at different latitudes, readings from observatories around the world show the same rising CO2 trend from one year to the next.   In the book, CO2 Rising, Tyler Volk (2008) writes, "Data from Alaska and Samoa fit right in with the trend from Mauna Loa and the South Pole, where monitoring was begun nearly 20 years earlier.  We are witnessing a global phenomenon.  CO2 is rising everywhere, and at about the same rate" (pp. 40 -41).

 

More Info

 

NOAA-ESRL GMD  Global CO₂

NOAA-ESRL GMD  NOAA-ESRL calculation of global averages

NOAA-ESRL GMD  Cooperative Air Sampling Network

SkS  CO2 Comparison Chart | Mauna Loa vs. Global Average

SkS   CO₂ Comparison Chart | Mauna Loa, Alaska, Samoa, South Pole

 

Reference

 

Volk, T. (2008). CO₂ rising: The world's greatest environmental challenge (2010 paperback ed.). Cambridge, MA: MIT Press.

 

Charts

Charts for Mauna Loa CO₂

 

Below are two NOAA charts and three Scripps charts.   Each chart shows changes in CO2 concentrations at different time scales--from hourly to seasonally.  These charts all use averages of readings at the Mauna Loa Observatory in Hawaii that started in March 1958.

 

NOAA Recent Monthly CO₂ Averages

Source Graphic  NOAA-ESRL [web + png + pdf]

 

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NOAA Monthly CO₂ Averages
Scripps Data 1958 - 1974  |  NOAA Data  1974 - Present  

Source Graphic  NOAA-ESRL [web + .png + .pdf]

 

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Scripps Monthly CO₂ Averages
March 1958 - Present Source Graphic  Scripps CO2 Program [web + .png + .pdf] 

 

 

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Scripps Hourly, Daily & Weekly CO₂ Averages for the Past Month

Source Graphic  Scripps Keeling Curve [web + .png]

 

 

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Scripps Daily & Weekly CO₂ Averages for the Past 6 Months

 Source Graphic:  Scripps Keeling Curve [web + .png]

 

 

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More Scripps Graphics

Scripps CO₂ Program   Mauna Loa Graphics Gallery

Scripps Keeling Curve Website   1 Week    1 Month    1 Year    2 Years    Since 1958    Since 1700    800,000 Years

 

 

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KC Monthly Web Widget

 

CO₂.earth features this web widget on its home page with html code (available in 9 sizes) from show.earth.

 

 

 

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*** More Data

 

Mauna Loa CO₂

 

CO₂.Earth  Daily CO₂ Data

CO₂.Earth  Weekly CO₂ Data

CO₂.Earth  Yearly CO₂ Data

CO₂.Earth  CO₂ Trend

 

About the Data

 

NOAA  How scientists measure background CO2 levels on Mauna Loa

 

Monthly Data at Other Stations

 

CSIRO  Monthly GHG Data at Cape Grim, Tasmania

NOAA  Monthly CO₂ data (in situ) at the South Pole Observatory, Antarctica

 

Data Updates

 

Is data reposted incorrectly? 

 

CO₂.Earth  Nudge Us