Keeling's record of data from Mauna Loa is considered one of the best and most consistent climate records anywhere, though scientists also use other sources for atmospheric data, including samples of air trapped in polar ice, to analyze CO2 levels in past millennia. (livescience.com)
Daughter of time: the postmodern midwife 1 For past millennia, midwives have served women in childbirth. (davis-floyd.com)