Question: How do you study palaeoclimatology?

James Pope answered on 29 Jun 2012:

Hi lucky260,

Palaeoclimateology is the coming together of a couple of groups of scientists. Firstly, palaeontologists drill cores of sediment either on land or from the sea bed and from that they are able to find microfossils called foraminfera, which are the remains of plankton that lived in the seas millions of years ago. When these plankton live they grow a shell which is made out of calcium and magnesium, and the ratio of these two elements can be measured by the palaeontologists and from this they can work out the temperature of that part of the ocean for different times over the past 80 million years. On land the same is done, but with pollen instead of plankton. We can look at the pollen and work out what sort of plants there were at that site at different times in the past and reproduce the vegetation cover which gives us an idea of temperature.

Then people like me, who use climate models come and we run climate models of these periods and experiment with the conditions we are not sure of such as greenhouse gas concentrations or the amount of ice sheets we have, and we can test the results we get against the data collected by the palaeontologists. Where we find a good match we know our model is working and we can then join the dots between all these sites.

3 million years ago in the Pliocene we have 100 sea sites and 202 land sites which we can join together to understand how the climate works.