Five, according to the World Wildlife Fund in 2007 (i.e. by 2012) http://news.sky.com/skynews/Home/Sky-News-Archive/Article/20080641265731?f=rss
Seven according to Bill McGuire in 2008 (i.e. by 2015) http://www.guardian.co.uk/books/2008/sep/20/politics.roundupreviews
Eight, according to Andrew Simm in 2008, (i.e. by 2016) http://onehundredmonths.org/ http://www.guardian.co.uk/environment/2008/aug/01/climatechange.carbonemissions
Ten according to Sir Nicholas Stern in 2006 (i.e. 2016) http://www.guardian.co.uk/politics/2006/oct/29/greenpolitics.economy
None? asks George Monbiot: 'Is it too late?' Yes, 'the end of late-summer sea ice within three to seven years' could 'flip the entire planet into a new climactic state'. Our only chance is if we succeed in 'cutting global emissions by over 8% a year'. http://www.facebook.com/pages/George-Monbiot/36456785002?ref=s#/note.php?note_id=36651523539&ref=mf
None, says James Lovelock http://www.guardian.co.uk/theguardian/2008/mar/01/scienceofclimatechange.climatechange