INFOGRAPHIC 23.10 MEASURING ATMOSPHERIC CARBON DIOXIDE LEVELS
Examining data from ancient air bubbles and present-day air measurements, scientists have recorded an approximately 40% increase in atmosphere CO2 levels since 1800.
SOURCE: Historic levels of CO2, NOAA National Climactic Data Center]; atmospheric CO2 at Mauna Loa Observatory, Scripps Institution of Oceanography and NOAA Earth System Research Laboratory.