Ice coring
Ice cores contain an abundance of climate information. Inclusions in the snow of each year remain in the ice, such as wind-blown dust, ash, bubbles of atmospheric gas and radioactive substances. The variety of climatic proxies is greater than in any other natural recorder of climate, such as tree rings or sediment layers. These include proxies for temperature, ocean volume, precipitation, chemistry and gas composition of the lower atmosphere, volcanic eruptions, solar variability, sea-surface productivity, desert extent and forest fires.
