Half a degree doesn't sound like much. And it isn't, if you are talking about a baccalaureate. But in a world of climate change, a half a degree increase in Baltimore's average temperature combined with average temperature increases in all the lower 48 states is confirmation of what the scientists are telling us:  the planet is warming.  Thus, the National Weather Service's release on Monday of revised 30-year average temperatures gives some satisfaction, or at least Schadenfreude, to those trying to lead (or push) their organizations into proactively managing climate change.

Or does it?  Here is how this news was reported in Tampa, Florida 

"Some of the changes emerge from tossing out statistical peaks and valleys from the 1970s, the weather service says. A shift in instrument locations could explain more change.

And the continued development around Tampa International Airport and Tampa in general could account for some of the warmer nights that helped push average temperatures higher for April through August.

A slight shift in equipment location at Tampa International Airport could also influence the low morning readings, the weather service says.

Or, the overall reason also could be changes in global climate, but that’s impossible to determine from readings at one location, the weather service says."

So if this is all statistics, what is one to do?  You could instead get your weather news from Montgomery, Alabama, which reported on the same news:

Updated theories of global warming and climate change predict a pattern of increasing temperatures. The theories are based on an increased amount of carbon dioxide in the atmos­phere leading to high tempera­tures.

The shift in temperatures is more likely associated with the Pacific Decadal Oscillation, said Dr. Roy Spencer, a princi­pal research scientist at the University of Alabama in Huntsville. Spencer also has served as a senior scientist for climate studies at NASA's Mar­shall Space Flight Center in Huntsville.

So which is it?  Statistics, decadal oscillation or climate change?  The statistics answer is easy to discern.  For Tampa, scientists cannot say that its temperature specifically is driven by climate change.  But when the whole country is changing, that is a different story.  Montgomery is a little more difficult.  I tracked down Dr. Spencer's webpage  and learned that he believes, "Climate change — it happens, with or without our help."  His research is into whether the climate change we are observing is natural or man-made.  He agrees that the climate is changing.

This seemingly disparate information contains a valuable lesson.  Where there is no controversy or skepticism, it is easy to make choices of what to do.  Where controversy surfaces, however, to move forward, one needs to understand precisely what is controverted.  And often, of course, that will have to be done by degrees as understanding matures.