The record covering the past millennium reduces the uncertainty regarding the pre-industrial concentration. Records covering the last glacial-interglacial transition and a fast climatic change during the last ice age show that the N 2 O concentration changed in parallel with fast temperature variations in the Northern Hemisphere. This provides important information about the response of the environment to global climatic changes. Comparison of our N 2 O measurements with previously published values for the past 1000 years. Each point of our record is either a single measurement or the mean value of two to six measurements on samples from the same core section.
Solid circles indicates reliable results.
Measurements that are out of range are marked by arrows at the corresponding time. For this time period, the uncertainty in Delta Age is better than 300 years. The time scale of the Byrd gas record was synchronized to that of the GRIP gas record with an uncertainty of 200 years.