Natural evidence of climate change
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The Distant Past
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scientists have found lots of ways to prove that climate was different in the past. Here are some ways they can tell how:
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historical sources
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there are sources such as books, newspapers, old photos and old drawings that provides evidence that climate change is happening
ice cores contain layers. the further down you go the older the ice
maisie - ice cores :
in the ice there are small air bubbles trapped in the layers of ice, these preserve air from the time snow fell.
fossilised animals, plants, and pollen that no longer live in the UK
this evidence isn't totally accurate
because the weren't intended
to be used to prove climate change
exists.
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Olivia-Tree Rings
landforms, like U-shaped valleys left by melting glaciers tell us the climate had warmed.
Periods of growth can be seen from the number of rings in a tree- each ring is year's growth
samples from ice cores taken from greenland and antarctica give scientists lots of info
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this evedence shows that every few hundred years the climate changes by 1-1.5 degrees hottor or colder than average temperatures today
to extract the ice they drill a core through the ice and measure the amount of trapped carbon dioxide in the ice layers
We can learn about the climate conditions through the rings
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If the climate is warmer and wetter the growth is greater
If the climate is cooler and drier the growth is smaller
warm periods are called interglacials. cold periods are called glacials, such as ice ages
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from this ice we can tell when there was cold period, glacial periods and warmer periods
ice sheets extended over continents in the northern hemisphere
warm periods last 10,000 and 15,000 years. cold periods last about 80,000 - 100,000 years, and
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the last time this happened was 30,000 and 10,000 years ago in the last known ice age