This award supports one aspect of the second Greenland Ice Sheet Project (GISP II). The GISP core from Summit, Greenland, will produce very old ice and paleoclimatic information with excellent time resolution, due to the prevailing accumulation rate and mean annual temperature. This effort will establish in this core a high resolution CO2 record, which is necessary to ultimately understand the natural disturbance in the carbon cycle, and the relationship and interaction between CO2 and climate. This record, when compared to temperature records (and particulate/chemistry/cosmogenic isotope records) will yield information on the cause/effect relationship of CO2 and climate, and on the mechanisms to produce atmospheric CO2 variations over different time scales. If the rapid variations in the last glacial could be confirmed, important information would be obtained on the climatic sequence of the anthropogenic alterations to the earth's trace gas involving in recent times.