<a href="http:&#x2F;&#x2F;a-sceptical-mind.com&#x2F;the-rise-and-fall-of-the-hockey-stick" rel="nofollow">http:&#x2F;&#x2F;a-sceptical-mind.com&#x2F;the-rise-and-fall-of-the-hockey-...</a><p>It turns out the data was blended, but it was weighted in an odd way to favor the spikey outcome at the end.  This is just one source, so take it with a grain of salt.