Guardian: As Suzanne Goldenberg reported in The Guardian yesterday, Arctic sea ice appears to have reached its annual minimum extent, at approximately 5.1 million square kilometers. This is the 6th-lowest extent since the satellite record began in 1979.
But in fact, scientists have also reconstructed Arctic sea ice extent data much further into the past. For example, Drs. Walsh & Chapman from the University of Illinois have estimated sea ice extent as far back as the year 1870 using a vast array of data...