Researched
Keeling curve (CO2 record)
Charles Keeling's CO2 measurements at Mauna Loa, begun in 1958, showed concentrations rising year after year with the seasons.
Open in the interactive tree →The first readings were about 313 ppm; the May 2026 peak was about 432 ppm. The Keeling curve turned the greenhouse effect from a calculation into an observation and is one of the longest continuous atmospheric records.
Prerequisites
- Photosynthesis discovered1779The yearly swing in the CO2 curve is plants taking up the gas by photosynthesis
- Greenhouse effect1896
- International Geophysical Year1957-1958Keeling's Mauna Loa record began during the International Geophysical Year