Evidence of earlier climates survives in ice cores, sediments, tree rings, mineral deposits, and chemical signatures. Discover how researchers reconstruct ancient atmospheres, ice ages, temperature shifts, and natural changes that occurred before modern measurements.
No thermometer recorded Antarctica 300,000 years ago. The celebrated temperature curve from the Vostok ice core is a reconstruction, built primarily from subtle differences in the hydrogen isotopes of the ice itself. It charts repeated cold glacial states and warmer interglacials across roughly...
The EPICA Dome C ice core transformed 3.2 kilometers of East Antarctic ice into a climate sequence spanning roughly 800,000 years. Its importance comes from more than reaching an impressive age. The core follows consecutive layers through eight glacial cycles, pairing evidence of Antarctic...
Deep inside Antarctic ice, small bubbles preserve samples of atmospheres that existed long before modern humans. Some contain air sealed during glacial periods when immense ice sheets covered northern continents; others date from warmer intervals when forests and coastlines occupied different...