Reading the Ice Cores
Trapped in Antarctic ice are tiny bubbles of ancient atmosphere — air that was last breathed by no one, sealed away thousands of years before the first human civilization. When scientists extract these ice cores and analyze the gas composition of those bubbles, they are reading the climate diary of the planet itself.
The story the ice tells is unambiguous. For 800,000 years, atmospheric CO2 oscillated between 180 and 280 parts per million, rising and falling with glacial cycles. Then, starting around 1800, the line goes vertical1. We are now at 424 ppm — a concentration not seen in millions of years.
The ice does not care about politics2. It records what happened. And what happened is that human civilization fundamentally altered the composition of Earth's atmosphere in the geological blink of an eye. The question is not whether this matters — the physics is clear. The question is what we do about it.
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