Global Warming Update


March Global Temperature Change*

March Rankings:  1880 - 2020 Temperature Record
Comparisons with 20th Century Global Average Surface Temperature
(Temperatures are not compared here with a pre-industrial baseline)



Change in

Warmest March
+0.92°C   +1.66°F
3rd Warmest March
+0.80°C   +1.44°F
Coolest March
-0.56°C   -1.01°F
    Data retrieved:
May 6, 2020

*Surface temperature changes relative to 20th Century global average (1901 - 2000)
Source data  NOAA-NCEI State of the Climate: Global Analysis  [Web + data download]

"Averaged as a whole, the global land and ocean surface temperature for March 2020 was 1.16°C (2.09°F) above the 20th century average of 12.7°C (54.9°F) and the second highest in the 141-year record. Only March 2016 was warmer at 1.31°C (2.36°F). The 10 warmest Marches have all occurred since 1990, with Marches of 2016, 2017, 2019, and 2020 having a global land and ocean surface temperature departure from average above 1.0°C (1.8°F). The March 2020 global land and ocean surface temperature departure tied with February 2020 and December 2015 as the third highest monthly temperature departure from average in the 1,683-month record. Only February and March 2016, when a strong El Niño was present in the tropical Pacific Ocean, had higher temperature departures.

"March 2020 marked the 44th consecutive March and the 423rd consecutive month with temperatures, at least nominally, above the 20th century average. According to NOAA's Climate Prediction Center, ENSO-neutral conditions were present across the tropical Pacific Ocean during March 2020. The March 2020 global land and ocean surface temperature departure from average tied with February 2020 as the highest monthly temperature departure without an El Niño present in the tropical Pacific Ocean. The three highest ENSO neutral temperature departures from average have all occurred in 2020. CPC states that ENSO-neutral is favored during the Northern Hemisphere spring (Southern Hemisphere fall). This forecast focuses on the ocean surface temperature between 5°N and 5°S latitude and 170°W to 120°W longitude, called the Niño 3.4 region.

"The global land-only and global ocean-only temperature departures from average for March 2020 were also near-record warm, behind the record set in March 2016. The global land-only March 2020 temperature departure of +2.05°C (+3.69°F) was also the fifth highest for any month for land surfaces in the 1,683-month record. The 10 highest monthly land-only temperature departures have occurred since December 2015. Meanwhile, the March 2020 global ocean-only temperature departure of +0.83°C (+1.49°F) tied with February 2016 and July 2019 as the seventh highest for any month for ocean surface on record.

"Regionally, South America and the Gulf of Mexico had their warmest March on record, surpassing their previous records set in 2010 and 1945, respectively. This was also South America's fifth and the Gulf of Mexico's fourth highest temperature departure for any month in the regional 1,323-month record. The Caribbean had its second highest March on record at 0.90°C (1.62°F) above average. Only March 2016 was warmer. Meanwhile, Europe, Africa, and Asia had a March temperature that ranked among their nine highest on record."

[NOAA/NCEI global analysis accessed May 6, 2020]


"The science is sobering—the global temperature in 2012 was among the hottest since records began in 1880. Make no mistake: without concerted action, the very future of our planet is in peril."

~ Christine Lagarde, in 2012
Managing Director, International Monetary Fund


NOAA/NCEI annual global analysis for 2018: 

The 2017 average global temperature across land and ocean surface areas was 0.84°C (1.51°F) above the 20th century average of 13.9°C (57.0°F), behind the record year 2016 (+0.94°C / +1.69°F) and 2015 (+0.90°C / +1.62°F; second warmest year on record) both influenced by a strong El Niño episode. The year 2017 is also the warmest year without an El Niño present in the tropical Pacific Ocean.

2017 also marks the 41st consecutive year (since 1977) with global land and ocean temperatures at least nominally above the 20th century average, with the six warmest years on record occurring since 2010. Since the start of the 21st century, the global temperature has been broken five times, three of those being set back to back (2014–2016). The yearly global land and ocean temperature has increased at an average rate of 0.07°C (0.13°F) per decade since 1880; however, the average rate of increase is twice as great since 1980. From 1900 to 1980 a new temperature record was set on average every 13.5 years; however, since 1981 it has increased to every 3 years.

Overall, the global annual temperature has increased at an average rate of 0.07°C (0.13°F) per decade since 1880 and at an average rate of 0.17°C (0.31°F) per decade since 1970."

[NOAA/NCEI global analysis for 2018 accessed February 18, 2019].


"Globally-averaged temperatures in 2015 shattered the previous mark set in 2014 by 0.23 degrees Fahrenheit (0.13 Celsius). Only once before, in 1998, has the new record been greater than the old record by this much."

~ NASA Goddard Institute for Space Studies [NASA post of January 20, 2016]


Before the end of 2015, scientists projected that average global temperature increase for 2015 will exceed 1°C above pre-industrial levels.  The years 1850-1900 are used as the pre-industrial baseline by the MET Office and Climate Research Unit at the University of East Anglia in the UK.  The MET Office released this statement in November 2015:


"This year marks an important first but that doesn't necessarily mean every year from now on will be a degree or more above pre-industrial levels, as natural variability will still play a role in determining the temperature in any given year.  As the world continues to warm in the coming decades, however, we will see more and more years passing the 1 degree marker - eventually it will become the norm."

~ Peter Stott
Head of Climate Monitoring and Attribution (MET Office)


>> Read More


Annual GHG Index (AGGI)


NOAA's Global Monitoring Laboratory posts an Annual Greenhouse Gas Index (AGGI) that tracks yearly changes in the warming-influence of long-lived, trace greenhouse gases.  

As reported May 14, 2020, by NOAA-ESRL with an update to its AGGI webpage, the combined influence of all greenhouse gases in the Earth's atmosphere reached the equivalent of 500 ppm CO2 in 2019.  With carbon dioxide and other GHGs continuing to accumulate in the atmosphere, despite the global COVID-19 pandemic, humanity's climate crisis has now surpassed the symbolic milestone of 500 ppm CO2e.  

Observation by CO2.Earth:  No media releases or coverage of the 500 ppm CO2e milestone announcement has been found on any website in the world, including the UNFCCC website which has an ultimate objective to stabilize the concentration of greenhouse gases in the atmosphere.  

2020 05 15 at 8.20.58 AM screenshot noaa 2019 co2e 500 ppm

The above graphics are a screenshot from the NOAA AGGI Intro webpage.



More information about the greenhouse gas index is posted on the NOAA AGGI Intro webpage.  Technical details, including a table with annual CO2-equivalents since 1979, are on the full NOAA AGGI page.   

The index quantifies the global climate forcings of CO2, CH4 (methane), N2O (nitrous oxide), CFC12, CFC11 and 15 minor GHGs. 

Changes in the AGGI are reported from 1979 (AGGI = 0.785) until present (2019: AGGI = 1.45).   The index uses 1990 as a baseline year with a value of 1.  The index increased every year since 1979.  The chart below shows the similar trajectory of CO2 and the AGGI.

NOAA Annual GHG Index

Source Graphic  NOAA Annual Greenhouse Gas Index (AGGI)



Global Average Abundances of Major, Long-Lived Greenhouse Gases

Global Average Concentrations for Major GHGs

Source Graphic  NOAA Annual Greenhouse Gas Index (AGGI) 





Butler, J.H. & Montzka, S.A. (2015) The NOAA Annual Greenhouse Gas Index (AGGI). Published online Spring 2015, retrieved October 5, 2015, from



Atmospheric Greenhouse Gas Data


GAW Programme Data Collection

For CO2, 50 WMO countries contributed CO2 data to the GAW World Data Centre for Greenhouse Gases (WDCGG).   Of these, about 50% are obtained from sites that make up the NOAA-ESRL cooperative air sampling network.  Other data contributors on the GAW network are Australia, Canada, China, Japan and many countries in Europe.  The WDCGG publishes a list of contributing sites and countries that collect CO2 and other greenhouse gas data.


GAW  World Data Centre for Greenhouse Gases (WDCGG)

GAWSIS   GAW Station Informaiton System


More GHG Data


NOAA  Global Trends in Atmospheric Methane (CH4)

WMO  Greenhouse Gas Bulletin (updated annually)

WMO  Latest Greenhouse Gas Bulletin: Nov. 2014 [.pdf]


CDIAC  Blasing | Recent GHG concentrations  [Related: tools + sites]

AGAGE (.txt)  Atmospheric concentrations for 8 GHGs (including CH4)

AGAGE  Charts | Atmospheric concentrations of 33 compounds

AGAGE  Atmospheric concentrations of 33 compounds | index of .txt files




MIT  400 ppm? Add other GHGs, and it's equivalent to 478 ppm



CO2 Past.  CO2 Present.  CO2 Future.