CO2 Now


What the world needs to watch

Global warming is mainly the result of CO2 levels rising in the Earth’s atmosphere. Both atmospheric CO2 and climate change are accelerating. Climate scientists say we have years, not decades, to stabilize CO2 and other greenhouse gases.

To help the world succeed, makes it easy to see the most current CO2 level and what it means. So, use this site and keep an eye on CO2.  Invite others to do the same. Then we can do more to send CO2 in the right direction.

Watch CO2 now and know the score on global warming, practically in real time.

Weekly Data | Atmospheric CO2 PDF Print E-mail

September 2015

Atmospheric CO2  - Weekly Data
Mauna Loa Observatory   |   NOAA-ESRL Data


Atmospheric CO2 

Sept. 20 - 26, 2015

397.33 ppm

(last week)

Sept. 20 - 26
, 2014



(1 year ago)


Sept. 20 - 26, 2005


376.03 ppm

(10 years ago)


Atmospheric CO2  -  Increase Since 1800
Mauna Loa Observatory   |   NOAA-ESRL Data

As of Last Week

Increase Since 1800 

Sept. 20 - 26, 2015

+ 120.87 ppm

NOAA-ESRL updated weekly data on September 27, 2015.  ("ppm" means parts per million)


Weekly Data & Info (Mauna Loa Observatory) 


NOAA-ESRL  |  Weekly CO2 Data Since 1974

NOAA-ESRL  |  Weekly CO2 Information and Links 

Scripps CO2  |  Daily CO2 Reports

Scripps CO2  |  Historical CO2 Data @Keeling_Curve


More Data & Info (Mauna Loa Observatory)


CO2Now   |   Global CO2 Board

CO2Now   |   Monthly  CO2 Data (Mauna Loa)   

CO2Now   |   Annual CO2 Data (Mauna Loa & Global)

CO2Now   |  Acceleration of Atmospheric CO2


Daily & Weekly CO2 Graphs


The graph below is updated weekly by NOAA-ESRL.   It shows the daily and weekly (Sunday through Saturday) mean concentration of carbon dioxide measured in the atmosphere at the Mauna Loa Observatory in Hawaii, USA. 

Source:  NOAA - ESRL Weekly CO2 Trends  |  High Resolution PDF



The next graph from the Scripps CO2Program shows the latest weekly (and daily) data for atmospheric CO2 at the Mauna Loa Observatory.

Source:   Scripps CO2 Program:

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