Cobra Effect · Earth

The curve that tracks carbon dioxide

How patient measurements on a Hawaiian volcano revealed carbon dioxide rising.

7 cards, read aloud in 3:24, with a test and sources.

Three factory chimneys with rising smoke beside a wavy sea

In the 1950s, nobody knew for sure whether the carbon dioxide in the air was rising.

Burning coal, oil and gas releases carbon dioxide. Some scientists thought the oceans would soak up almost all of it. Earlier measurements of the gas varied so much that no clear trend could be seen. A young chemist, Charles David Keeling, set out to measure it precisely.

In March 1958, Keeling’s instrument began measuring the air high on Mauna Loa, in Hawaii.

The observatory sits near the top of a volcano in the middle of the Pacific Ocean. Air reaches it after crossing thousands of kilometres of ocean, far from cities and forests. The instrument measured carbon dioxide with great care, checking itself against reference gases. That first year, the air held about three hundred and fifteen parts per million.

Within a few years, the measurements showed the whole planet breathing.

Each year the level peaked in about May, and fell to its lowest around September or October. In spring and summer, plants across the northern half of the world grow and take in carbon dioxide. In autumn and winter, leaves fall and plants rot, releasing it again. The northern hemisphere has far more land and plants than the south, so its seasons set the rhythm.

Beneath the yearly ups and downs, the level kept climbing.

Year after year, each peak was higher than the one before. The rise followed the growing amounts of coal, oil and gas being burned. The line of measurements became known as the Keeling Curve. It is one of the most famous records in all of science.

Keeling had to fight to keep the measurements going.

Some funding agencies saw measuring the same thing year after year as routine monitoring, not research. In the 1960s, cuts to funding left a small gap in the record. Keeling argued that a long, careful record was worth far more than a short one. After his death in 2005, his son Ralph Keeling carried the work on at Scripps, in California.

In 2022, lava from Mauna Loa cut off the observatory, and the measurements moved.

In November 2022 Mauna Loa erupted, and lava crossed the road to the observatory, taking out its power lines. Scientists set up a temporary site on the summit of nearby Maunakea to keep the record going. The yearly peak is now more than four hundred and thirty parts per million. That is far higher than at any time in the ice core record, which reaches back eight hundred thousand years.

So when a change is slow and quiet, ask who is keeping the record.

A single measurement would have shown almost nothing. Only decades of patient, careful measurement revealed the planet breathing, and the steady rise beneath it. The level has risen by more than a third since Keeling began. The record goes on, every day, near the top of a volcano in the Pacific.

Sources

Nearby ideas

All stories

Cobra EffectIdeas worth knowing
Streak 0 daysRead 0 of 0Known 0Kept 0
· · · All stories
Every story is written to a rule: framing can be invented, facts cannot, and a tale that is probably a legend says so. Narration and pictures are generated once and kept. Your progress is saved on this device and in a record of its own on the server, so you can pick it up on another one. Nothing else about you is collected, and there is a button to delete the lot. Privacy.