judgment and statistical analysis of a body of evidence (e.g. observations
or model results), then the following likelihood ranges are used to express the assessed probability of occurrence: virtually certain >99%;
extremely likely >95%; very likely >90%; likely >66%; more likely than not > 50%; about as likely as not 33% to 66%; unlikely <33%; very
unlikely <10%; extremely unlikely <5
/media/loftslag/IPPC-2007-ar4_syr.pdf