Microscopic fossil shells can reveal climatic conditions by the amount and type of calcium carbonate in their shells.
CarbonBrief.org has a great primer on “How ‘proxy’ data reveals the climate of the Earth’s distant past” ¾
Microscopic fossil shells can reveal climatic conditions by the amount and type of calcium carbonate in their shells.
CarbonBrief.org has a great primer on “How ‘proxy’ data reveals the climate of the Earth’s distant past” ¾