Keeling Curve — Atmospheric CO₂ Breathing

This simulation visualizes the Keeling Curve, the longest continuous record of atmospheric CO2 concentration, measured at Mauna Loa Observatory since 1958. A rotating Earth breathes with the seasons: a global shell of CO2 particles brightens toward orange as the Northern Hemisphere's autumn and winter release carbon from decaying vegetation, then cools toward green as spring and summer growth pulls it back down through photosynthesis. Because the Northern Hemisphere holds most of the planet's land and seasonal vegetation, its growing cycle dominates the whole atmosphere's seasonal swing even though CO2 mixes globally within about a year. Layered underneath that yearly breath is the real long-term trend: a steady anthropogenic climb from roughly 315 ppm in 1958 to well over 420 ppm today, traced live on the sawtooth graph below the globe. Adjust the time speed to watch a single season unfold slowly or run six decades of accumulation in seconds.