How can you tell climate from ice cores and ancient rocks?
Well, there are certainly many methods to find the content of the ice and therefore the air at a certain period of time. But the hard part is to date accurately. Now, since I live in Norway where we have glaciers in the summer, I can tell you this: As the ambient temperature reaches melting point, micro-organisms like fungi grows on the ice giving it a brown reddish colour. It is through such individual techniques that the core of ice can be dated in layers. Each layer is then tested for its content of CO2 and different gas and small particles such as seeds. One thing we often forget is that the air around us contains a lot of dust and particles that are telltales of how life and climat is at the moment. Without dust in the air, clouds can’t form because water needs to give away energy in order to condense. That’s the reason cloud seeding (spreading particles from an aircraft) is used to induce rain in dry regions.
