"Hottest year ever" record relied on data adjustments

The recent announcement by NASA that 2014 was (maybe, kinda sorta) the hottest year on record relied on a big heat wave in South America for the record high global temperature reported.  But if you look at South America, you see a very large part of it is Amazon rain forest where there are precisely zero surface stations reporting temperatures to NASA and the other databases.

As a matter of fact, it boils down to three stations that are used to "infill" data to the bulk of the continent.  There's quite some interesting adjustments being made to the data from those stations:

As we so often see, older temperatures are adjusted downwards and recent temperatures are adjusted upwards:

So we find that a large chunk of [NASA's] hottest year is centred around a large chunk of South America, where there is little actual data, and where the data that does exist has been adjusted out of all relation to reality.

Other than that, it's awesome.