CO2 levels just broke another record. Here's what that means

When man first walked on the moon, the carbon dioxide concentration in Earth's atmosphere was 325 parts per million (ppm).

By 9/11, it was 369 ppm, and when COVID-19 shut down normal life in 2020, it had shot up to 414 parts ppm.

This week, our planet hit the highest levels ever directly recorded: 430 parts per million.

For 67 years, the observatory on Hawaii's Mauna Loa volcano has been taking these measurements daily — tracking the invisible gas that is building up in our atmosphere and changing life on Earth.

The record is known as the Keeling Curve. Charles David Keeling began those recordings, some of the first in the world to measure CO2 concentration over time.

Measurements of C02 in the atmosphere at the Mauna Loa Observatory show levels steadily rising — with annual variatio