Satellite monitoring of the Arctic only began in 1978, giving us less than forty years of reliable data.This may not be enough to establish what is normal – or abnormal – for the region.The earlier period, between 740,000 and 430,000 years ago, was characterized by less pronounced warmth in interglacial periods in Antarctica, but a higher proportion of each cycle was spent in the warm mode.
Moreover, it is not possible to infer the abundance of greenhouse gases in the atmosphere from marine records.
Undaunted, fresh predictions have been made in every subsequent year.
One problem that persists is that there is still only a relatively short series of direct measurements on which to base our understanding of the Arctic.
The project was completed by the United States Antarctic Program(USAP) and was funded by the National Science Foundation (NSF).
The focus of the project was to develop records spanning the last ~ 80,000 years of the concentration of greenhouse gases in the atmosphere and Antarctic climate, and to do this with the highest possible time resolution.