Atmospheric CO2 concentrations (ppm) derived from in situ air measurements at Mauna Loa, Observatory, Hawaii.
Credits: Dr. Pieter Tans (NOAA/ESRL), Dr. Ralph Keeling, S. J. Walker, S. C. Piper and A. F. Bollenbacher (Scripps Institution of Oceanography)
1000 YEARS AGO - 1958
Historical CO2 records from the Law Dome DE08, DE08-2, and DSS ice cores.
Credits: D.M. Etheridge, L.P. Steele, R.L. Langenfelds, R.J. Francey and the Division of Atmospheric Research, CSIRO, Aspendale, Victoria, Australia
800,000 YEARS AGO - 1000 YEARS AGO
Changes in past atmospheric carbon dioxide concentrations can be determined by measuring the composition of air trapped in ice cores from Antarctica. So far, the Antarctic Vostok and EPICA Dome C ice cores have provided a composite record of atmospheric carbon dioxide levels over the past 800,000 years.
Credits: Bernhard Bereiter, Sarah Eggleston, Jochen Schmitt, Christoph Nehrbass-Ahles, Thomas F. Stocker, Hubertus Fischer, Sepp Kipfstuhl and Jerome Chappellaz. 2015.
The Scripps Institute report oxygen measurements as changes in the O2/N2 ratio of air relative to a reference. They compute:
where (O2/N2)sample is the O2/N2 mole ratio of an air sample and (O2/N2)reference is the O2/N2 mole ratio of their reference. Their reference is based on tanks of air pumped in the mid 1980s which are stored at the Scripps Institute laboratory in La Jolla, California.
CARBON DIOXIDE (CO2)
A minor but very important component of the atmosphere, carbon dioxide is released through natural processes such as respiration and volcano eruptions and through human activities such as deforestation, land use changes, and burning fossil fuels. Humans have increased atmospheric CO2 concentration by more than a third since the Industrial Revolution began. This is the most important long-lived "forcing" of climate change.
GREEN HOUSE EFFECT
CO2 sticks around
CO2 remains in the atmosphere longer than the other major heat-trapping gases emitted as a result of human activities. It takes about a decade for methane (CH4) emissions to leave the atmosphere (it converts into CO2) and about a century for nitrous oxide (N2O).
After a pulse of CO2 is emitted into the atmosphere, 40% will remain in the atmosphere for 100 years and 20% will reside for 1000 years, while the final 10% will take 10,000 years to turn over. This literally means that the heat-trapping emissions we release today from our cars and power plants are setting the climate our children and grandchildren will inherit. Read more...