These data are compiled fromWikipedia. Please note that Wikipedia is an apocryphal source, being edited by and subject to
direct public input. It is, nevertheless, presented by some as source material for the global warming discussion. So let us consider it.

Approximate number of petition signatories=19,700
Identity confirmed by independent entity rate=90%
Revised number verified signatories=17,730
Signatories in direct, related fields rate=13%
Number in direct, related fields=2304
Signatories in extended, related fields rate=25%
Number in extended, related fields=4432
Total verified, qualified rate=38%
Total number verified, qualified=6736

The Scientific American provided these data. 26 of 1400 PhD level climate scientists listed on the petition (<2%) were contacted.
Of this pitifully small and non-representative sample fully 42% (11/26) stated they sill agreed with the petition statement.
26/6376=sample/Total nunber verified, qualified=0.4%

Compare this with the similar figures for the IPCC:
Approximate membership=2500
Qualified members in direct, related fields=70 (<3%) -From Patrick J. Michaels, Meltdown