How are hydrogen isotopes used to infer polar temperature ...

[mwit1967]

How are hydrogen isotopes used to infer polar temperature records?
 
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Question 2

What are thought to be the primary causes of this increase?
 
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Answer to Question 1

Ice cores can be used to estimate past surface temperatures by looking at oxygen or hydrogen isotopes. By analyzing the isotopic composition of frozen water-ice in polar ice cores, we can learn something about the local temperature at the time the ice formed. Warmer water temperatures speed up the evaporation rates of both H2O and HDO. HDO represents water molecules that contain deuterium. Warmer temperatures correspond to a higher HDO content in the snow that falls over Antarctica and in the ice that forms from the snow.

Answer to Question 2

Apparently, humans have been responsible for the entire 39 increase in atmospheric CO2 concentration over the past two centuries. Deforestation of North America in the 19th century contributed to the initial rise, and then fossil fuel burning and tropical deforestration contributed after that.

[mwit1967]

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[amandanbreshears]

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