Lake sediments preserve changing chemical and biological signals.

Ice cores record atmospheric conditions at broader scales.

Pollen and plant remains can reveal vegetation history.

Together, these records help distinguish between different versions of the climate story.

A colder world, a drier world and a more variable world are not identical problems.

A farmer may survive a cold summer if moisture is adequate, but a dry sequence can reduce pasture even when temperatures are not dramatically lower.

The distance involved is easy to underestimate.