All things being equal, the number of temperature records should be about as many high records as low records. In fact, they are running 3 to 1 in favour of high records. My simple logic leads me to conclude that 2 out of three high temperature records are the result of global warming.
Mmmh ... I'm afraid not, although those records go with the general picture of warming.
The most important element about it is not the proportion of record highs and lows -besidides many record low temperatures being also a consequence of global warming- but the frequency of records in one weather station.
As currently there aren't denialists here swarming around, we can talk as "complicated" as it is needed, and it's good to "remember" that a measurable random process of which is possible to get a record high or low value will show those record appearing in intervals increasingly long. I mean, if you repeatedly throw a thousand dice and sum the value of all of them you'll see the record high value to appear increasingly scarce. For instance, the first throw can get a 2963, first record high, the second throw 3069, new record high, the third an fourth ones 3063 and 2798, but the fifth can be 3145, a new record high. Before a thousand throws you'll perhaps have a record high of 3247 and you'll have to maybe wait until throw number 1845 to have a new record high of 3276, but then you'll have to wait until the 4104th repetition to get a new high, but I assure you that, unless you get by chance a read of 6000 or a little less, you'll see the new highs coming increasingly rarely.
When you take a weather station, a rural one for the sake of the argument, you may find patterns like this one:
record high temperature for July:
1886 26.2° (the year the station was settled)
1887 27.9°
1891 28.3°
1903 30.4°
1931 31.6°
1933 31.9°
1940 32.1°
1968 32.2°
1987 32.5°
1995 32.9°
2006 33.3°
For laymen this is telling nothing. They may even argue about some cycles, for instance, that the thirties and forties were very hot because of the sun and whatever they may say with a size 6 foot set on reality and the other foot, size 15, firmly grounded on wishful thinking. But the fact of repeatedly broken record highs without an increase in the interval length is a sign of warming. When that happens worldwide, covering 75 or 80% of the planet, it is an unequivocal sign of warming.
Of course, large regions may be not experiencing this pattern in a clear manner, for instance, the fabulous continent of Biblebeltia, and her inhabitants may claim that they are suffering record lows instead. Well, the matter is that record lows are also not so scarce as expected, so, what is it? cooling and warming simultaneously?
The fact is that mean temperature and weather variability are in increase worldwide, what is consistent with the current global warming process. As a consequence in many regions record lows look like those of a random process within a frame of stability. Variability make record lows more probable; warming make them more scarce. The result is headlines telling "the coolest X since 1941 (or 1968, or 1927)". They fail to reckon that, if climate is stable and weather is a random, noisy process, as new weather stations have been created in the last 30-80 years, they should be a flow of headlines telling "the coolest X
ever". That hardly happen.
, i.e. there has been a X fold (and that is IMHO "huge") increase in freak weather events.
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. The 97% is robust, and should be used as often as possible.