If we include only human sources of CO2 and aerosols, then we can explain 60 to 70 % of past variations. (climateaudit.org)
Several studies have explored the use of unequally weighted means, with the weights based on the models» performance in simulating past variations in climate, typically using some performance metric or collection of metrics... (realclimate.org)
Lorraine Lisiecki is in the business of understanding past variations in ocean circulation. (forecastpod.org)