#TAKING A BREAK MEME FULL#

Hence the GISS data are clearly more useful in this respect, and the supposed pause in warming turns out to be just an artifact of the “Arctic hole” in the Hadley data – we don’t even need to refer to natural variability to explain it. in and out of the Arctic, and the whole thing becomes ill-determined (because we don’t know how much that is). One would have to account for the heat flow across the boundary of the “hole”, i.e. But if data coverage is not really global, the heat budget is not closed. That’s because global temperature follows a simple planetary heat budget, determined by the balance of what comes in and what goes out. If we want to relate global temperature to global forcings like greenhouse gases, we’d better not have a “hole” in our data set. The largest warming has occurred over the Arctic in the past decade and is missing in the Hadley data. The animated graph shows the temperature difference between the two 5-year periods 08. Why do these two surface temperature data sets differ over recent years? We analysed this a while ago here, and the reason is the “hole in the Arctic” in the Hadley data, just where recent warming has been greatest.įigure 2. Even the highly “cherry-picked” 11-year period starting with the warm 1998 and ending with the cold 2008 still shows a warming trend of 0.11 ✬ per decade (which may surprise some lay people who tend to connect the end points, rather than include all ten data points into a proper trend calculation). The blue lines show the two most recent ten-year trends (0.18 ✬ per decade for 1998-2007, 0.19 ✬ per decade for 1999-2008) and illustrate that these recent decadal trends are entirely consistent with the long-term trend and IPCC predictions. The green line shows the 25-year linear trend (0.19 ✬ per decade). The red line shows annual data, the larger red square a preliminary value for 2009, based on January-August. Global temperature according to NASA GISS data since 1980. 1990-1999, 1991-2000 and so on) have all been between 0.17 and 0.34 ✬ per decade, close to or above the expected anthropogenic trend, with the most recent one (1999-2008) equal to 0.19 ✬ per decade – just as predicted by IPCC as response to anthropogenic forcing.įigure 1. It does show up to some extent (no cooling, but reduced 10-year warming trend) in the Hadley Center data, but it does not show in the GISS data, see Figure 1. (2) It is highly questionable whether this “pause” is even real. Of course, the warming trend keeps going up whilst natural variability just oscillates irregularly up and down, so over longer periods the warming trend wins and natural variability cancels out. ~0.2 ✬) and can thus compensate for the anthropogenic effects. That simply is due to the fact that short-term natural variability has a similar magnitude (i.e. Even under conditions of anthropogenic global warming (which would contribute a temperature rise of about 0.2 ✬ over this period) a flat period or even cooling trend over such a short time span is nothing special and has happened repeatedly before (see 1987-1996).

(1) This discussion focuses on just a short time period – starting 1998 or later – covering at most 11 years. Although we have discussed this topic repeatedly, it is perhaps worthwhile reiterating two key points about the alleged pause here.

#TAKING A BREAK MEME FULL#

The blogosphere (and not only that) has been full of the “global warming is taking a break” meme lately.

Taking a break meme