It would have to have an effect that prevents any other known causal factors from also
affecting temperatures over the period in question.
Not exact matches
Until you can provide one, one that explains why the known forcings
over the same
period of time had no
affect on
temperature, they are meaningless.
That land changes
over this
period may have slightly increased
temperature, and has had regional
affects upon climate, and multitude undefined possible effects.
It seems reasonable that such a cycle would
affect the observed trends
over the 30 - year
period of the satellite
temperature record.
This is close to the warming of 1.09 °C (0.86 — 1.31 °C) observed in global mean land
temperatures over the
period 1951 — 2010, which, in contrast to China's recorded
temperature change, is only weakly
affected by urban warming influences.
The idea is, if the change in surface
temperature over that
period is
affected by changes in cloud cover, but changes of the surface
temperature associated with the ocean warming are small, then changes in cloud cover must be driving the present global warming.
In a worldwide set of about 270 stations, Parker (2004, 2006) noted that warming trends in night minimum
temperatures over the
period 1950 to 2000 were not enhanced on calm nights, which would be the time most likely to be
affected by urban warming.