The trillion dollar guess and the zombie theory - Climate Change: The Facts - page 113

part of a cloud, it condenses out in less than a day. The amplification is called positive
feedback, and this particular feedback from water molecules is one of the biggest single
factors in climate models. 7 There are claims that it doubles the effect of all other forms of
warming. 8 Here's the line from the 1979 Charney report:
A plausible assumption, borne out quantitatively by model studies, is that relative humidity remains unchanged. The …
increase in absolute humidity … provides a positive feedback. 9
That's it: the foundation for multinational global action comes from a 'plausible
assumption'. Hey—but it was backed by 1970s computer models. They go on to say those
same models 'assume fixed relative humidity'. What's plausible is that if you use models
that assume relative humidity stays the same, those models will confirm that relative
humidity will stay the same.
Today, not much has changed. The modelers assume that CO 2 has caused most of the
warming since the industrial revolution, and for the most part, they also assume relative
humidity stays the same. The models then show that CO 2 caused most of the warming and
thus the assumption about humidity was 'right'. If some other factor caused some of that
warming both points would be wrong.
The hot-spot that wasn't
The humidity that supposedly amplifies the warming is not just any old humid patch
anywhere, but the thin layer near the top of the troposphere, about ten to twelve kilometres
above the tropics. This is where the action is. Models predict faster warming there, and the
trendsshowupasared'hot-spot'ongraphs.Butit'shardtomeasure.It'snotlikescientists
can poke gauges up there on long sticks from the office.
The best data we have comes from weather balloons, which rise up through the layer
and radio the information back before they explode. We've released 28 million or so of
these since the late 1950s, and the trend up there is unmistakably not what the models
expected. Instead of getting more humid as the air warmed, it got less. 10 Temperatures also
didn't warm as much as they were supposed to. 11 The result was stark in the colour maps
of the atmosphere. Yellow is not red.
Where was that positive feedback?
Otherdatakeptcomingintoo.Temperaturerecordingsfromallfourmajorglobaldatabases
unexpectedly flat-lined together, which wasn't a problem itself, except that it showed that
the models don't understand the climate. Around the world, 6,000 boreholes were drilled