And while we're doing that, let's also see if we can figure out why spring is earlier and fall is later over the past 130 years or so -- just in case we're concerned GISS might be wildly in error or something like that.
Global Warming Rushes Timing of Spring
(I'm a little curious where that 8 hours earlier spring green-up since 1982 is from)
There's been global warming, who knew? The problem is that looking closely you won't find a very good match to the GISS data. Take almost any example at random (e.g. http://www.ouranos.ca/doc/Indicateurs/Vincent.pdf) and you will see overall warming with no particular match to GISS. Different parameters (e.g. record lows vs last frost) have very different curves. A lot of them are flat since the 1970's where GISS has its big warming.