(April 28, 2013 at 4:51 pm)pocaracas Wrote:(April 28, 2013 at 4:35 pm)A_Nony_Mouse Wrote: Notice what happens when you move the zero up and down. The zero point is arbitrary. You can shift it so the zero is at +1 or -1 or whatever.
Maybe I'm reading the plot wrong, but the zero seems to be the temperature at 1900 (start of the horizontal axis). Everything else is the difference to the temperature at 1900.
IF that is the interpretation, temp in 1900, why not pick some later year? Say I pick the blue one that looks like around 1917 or the red one around 1922 and make either of them zero. That shifts the chart immensely. There is NOTHING meaningful or sacred about years that end in 0 or 00. 1900 is both arbitrary and capricious.