Atmospheric carbon dioxide CO2 has been monitored at Mauna Loa Observatory since 1958. Many other sites world-wide have been monitoring CO2. They all see the same increasing trend. Click on the graph to examine an interactive version which allows you to zoom in on any section. The blue line is the trend of the data. The varying red line is the monthly plot of values. The red line rises and falls with changes in the growing season primarily in the northern hemisphere. Summer months allow plants to use the CO2 to decrease it as they make O2 using photosynthesis. Winter months produce a rise in CO2 due to decomposition. Close inspection of daily records also shows the CO2 has a cyclical pattern between daytime and nighttime hours. (Not shown on this graph scale.)
Climate scientists also keep track of the global temperature using thousands of land and ocean recording stations world-wide. The trends of those world-wide temperatures also show a rise. When the CO2 and global temperature graphs are overlaid, they show a strong correlation, especially in the most recent decades. This chart comes from the National Climate Assessment published by the U. S. government in 2014. The horizontal line is the long-term average global temperature over land and sea since 1880 to now.
The National Climate Assessment summarizes the impacts of climate change on the United States, now and in the future. A team of more than 300 experts guided by a 60-member Federal Advisory Committee produced the report, which was extensively reviewed by the public and experts, including federal agencies and a panel of the National Academy of Sciences.
Clearly, it is important to know the behavior and concentration of CO2 in the atmosphere if we are to better understand the future impacts of global warming on the planet and the populations on it. The CO2 concentrations are not exactly the same everywhere. Certain regions use up CO2 a little more readily, such as forests. They act as sinks. Regions with less vegetation and large human populations tend to produce a little more CO2 than the average. They act as sources. The oceans also have regions of sinks and sources. None of these deviate much from the global average. But, the trends of CO2 and global temperature are unmistakably linked and rising.
Monitoring of global CO2 has been going on for a long time. Maps are made showing the concentrations such as this one from May 2013. It is from the AIRS instrument on the NASA AQUA satellite. The instrument monitored over 2000 channels of infrared light in the layer of the atmosphere where most weather occurs. It has wide global coverage. Yellow shows high CO2 concentrations. The northern hemisphere shows that as widespread because the growing season in May had not yet begun.
To gain finer resolution and answer questions about the transport of CO2 horizontally and vertically in the atmosphere, a new satellite, Orbiting Carbon Observatory-2, was launched July 2, 2014. OCO-2 is part of a train of satellites following one another in north-south polar orbit. They are called the A-Train. Coverage of the Earth will be 100%. It will view vertical profiles of the CO2 concentrations with high resolution and give a more detailed look at the sinks and sources of CO2 throughout the seasons for the coming years.
OCO-2 is currently undergoing calibration and validation of the instruments. That involves directing the multiple wavelength light beam down to places that also have ground based instruments in order to gauge the comparison of results. Once the calibration phase is complete, the data can be gathered and distributed to the science community for analysis. On September 5, 2014, OCO-2 passed over Caltech and JPL near Pasadena, CA. This image was released by the NASA Earth Observatory site. Each dot represents a unique measurement of CO2. Their size and color show the value in parts per million. The value over Pasadena by OCO-2 was 402 ppm. The ground based value was 399. This close agreement is very encouraging for the calibration and validation team. World-wide coverage in such high resolution will add tremendously to our knowledge and understanding of the behavior of CO2 in the atmosphere and how it impacts the future of global warming.
Scientists at NASA Goddard Space Flight Center released this video of computer modeled CO2 distribution and circulation during the year 2006. Carbon dioxide swirls as winds move it away from its sources. Notice the differences in the northern and southern hemispheres. The growth cycle of plants and trees changes the CO2 with the seasons.
Produced by a computer model called GEOS-5, created by scientists at NASA Goddard’s Global Modeling and Assimilation Office.
The visualization is a product of a simulation called a “Nature Run.” The Nature Run ingests real data on atmospheric conditions and the emission of greenhouse gases and both natural and man-made particulates. The model is then left to run on its own and simulate the natural behavior of the Earth’s atmosphere. This Nature Run simulates January 2006 through December 2006.
While Goddard scientists worked with a “beta” version of the Nature Run internally for several years, they released this updated, improved version to the scientific community for the first time in the fall of 2014.
Thanks to my nephew for pointing me to this video.