Summary Ice from the Greenland and Antarctic ice sheets contain air from the time the ice was formed. We extract that air and are able to reconstruct the past atmospheric composition. Over the past 10 years, we have been very successful implementing continuous methane concentration measurements from ice cores. The new instrument we are able to purchase through this grant will be used to measure the methane concentration from our current Greenland drilling project EGRIP reaching about 80kyr back in time. In the next 5 years, the international drilling project EPICA Oldest ice in Antarctica will surface core that is up to 1.5 million years old. We will obtain unprecedented knowledge of the composition of the past atmosphere more than a million years ago in high time resolution.