I deny nothing. It is true that the rate of change in global surface temperatures has been zero for several years.
Exactly how many years depends on which data series you look at, the NASA data shows around 12, however it also showed November 2013 as the hottest November in the record. The RSS data series has a longer 'pause', that series is satellite data which is actually an estimate the temperatures of the lower troposphere (about the lowest 10km of the atmosphere). RSS convert brightness measurements from the sats into temperature via some clever maths taking into account viewing angle, orbital drift etc (you might call it a 'model').
Interestingly a group at the University of Alabama take the same brightness data, put it through a different model and the 'pause' in their series is considerably shorter. So when you hear 'GW has paused for x years' remember that the X could be a cherry-pick.
12-16 years is not really long enough to eliminate or average out natural variability. On a year-to-year basis the ENSO (EL Nino/La Nina) cycle brings warm or cooler water to the surface which can mask any forced trend. The 16 year period is skewed by the fact that 1998 brought the largest El Nino of the last century, pushing temps 2sd above the trend line, while the later part of the period was dominated by La Nina years. Plus the sun seems to have gone relatively quiet recently.
Meanwhile, not much over a pause in the accumulation of heat in the oceans, which is where most of it goes...
Exactly how many years depends on which data series you look at, the NASA data shows around 12, however it also showed November 2013 as the hottest November in the record. The RSS data series has a longer 'pause', that series is satellite data which is actually an estimate the temperatures of the lower troposphere (about the lowest 10km of the atmosphere). RSS convert brightness measurements from the sats into temperature via some clever maths taking into account viewing angle, orbital drift etc (you might call it a 'model').
Interestingly a group at the University of Alabama take the same brightness data, put it through a different model and the 'pause' in their series is considerably shorter. So when you hear 'GW has paused for x years' remember that the X could be a cherry-pick.
12-16 years is not really long enough to eliminate or average out natural variability. On a year-to-year basis the ENSO (EL Nino/La Nina) cycle brings warm or cooler water to the surface which can mask any forced trend. The 16 year period is skewed by the fact that 1998 brought the largest El Nino of the last century, pushing temps 2sd above the trend line, while the later part of the period was dominated by La Nina years. Plus the sun seems to have gone relatively quiet recently.
Meanwhile, not much over a pause in the accumulation of heat in the oceans, which is where most of it goes...
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