And yet your buddies can not grasp the concept that if the average temperature has risen over a 1/3 of a degree and stayed that way since 1998 that the temperatures for 2000 through 2010 would all be higher then the previous years...
Well, if you'll bear with my leanings toward the "brain-dead" positions of NOAA, NCAR, MIT's Global Change Program, and the world's scientific academies: Why? Who ever said atmospheric temperature would rise continuously, un-modulated by things like the 11 year solar cycle and ocean heat exchange cycles (at least two of which have been in their cool phases)?
1998 was biased to the upside by a strong el niño (yet barely holds the record, and only in the CRU surface dataset that excludes representation of much of the Arctic). Hence the problem with using a single year as a basis for comparison: The still-young atmospheric trend (think thermal inertia) is mixed with short-term variability that has little to do with Earth's radiative state. But last I read from the WMO and NOAA, the decade of 2000-2009 is the warmest on record (global average, with North America experiencing a relatively coolish period).