How do scientist know that the climate was like in prehistoric times?

Answer 1

They use climate proxies to infer characteristics of climate in the past. For examples, atmospheric gases become trapped in antarctic ice. Scientists can now drill into the ice and take a core sample, testing the ice to determine what the atmosphere was made of, and therefore how it behaved, in the distant past.

A:

One component, the temperature, of the archaic atmosphere may be determined by the ratio of two isotopes of oxygen. O16 and O18. Their contribution to the atmosphere is a function of temperature.

And in the very early Earth, there was little oxygen therefore there was little photosynthesis going on.

And in the late Carboniferous Era, the oxygen content rose to over 30%, indicating massive photosynthesis and a warm climate. In this era, some dragonflies grew to have a 75cm wingspan! Only possible with plenty of food and a warm climate.

Answer 2

They use climate proxies to infer characteristics of climate in the past. For examples, atmospheric gases become trapped in antarctic ice. Scientists can now drill into the ice and take a core sample, testing the ice to determine what the atmosphere was made of, and therefore how it behaved, in the distant past.

A:

One component, the temperature, of the archaic atmosphere may be determined by the ratio of two isotopes of oxygen. O16 and O18. Their contribution to the atmosphere is a function of temperature.

And in the very early Earth, there was little oxygen therefore there was little photosynthesis going on.

And in the late Carboniferous Era, the oxygen content rose to over 30%, indicating massive photosynthesis and a warm climate. In this era, some dragonflies grew to have a 75cm wingspan! Only possible with plenty of food and a warm climate.

Answer 3

Geologists don't find out about past climates. Geology is the study of the Earth, not climate. Anyways, climatologists can find out past climates by observing tree rings, ice cores, by modeling, cave deposits, coral reef bands, and historical documents with written information about past climates for farming and such.

Answer 4

There are two ways to establish atmospheric composition in an earlier time. One is by direct examination of air bubbles trapped in porous rock, or in metamorphic forms such as amber (crystallized sap). An indirect way is by analyzing the components of rocks in a geologic strata, to see how the minerals in each layer were affected when they were surface rocks.

Answer 5

Botanists can dig up leaves, and even pollen, to discover what plants lived in an area, and how well they grew. It's not an exact science, but their guesses are pretty good.