6.2.10 (HL)—Climate data collection

Choose a climate record by variable, spatial scale and timescale: direct instruments measure current conditions, while proxies extend the record indirectly.

Weather stations and observatories directly record local variables such as temperature and greenhouse-gas concentrations; radar maps precipitation; satellites observe broad atmospheric and land-use patterns. Ice-core isotopes, tree-ring chronology and peat-core pollen are indirect proxies.

Use radar to locate today's storm cells, an observatory for a long direct CO2 series, and an ice core to reconstruct ancient gas or isotope conditions.

Both direct and indirect records inform climate models; match resolution, calibration and uncertainty to the question.

A longer record is not automatically more direct or more precise.