"The unequivocal detection of the enhanced greenhouse effect from observations is not likely for a decade or more."

"The balance of evidence suggests a discernable human influence on global climate."

"There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities."

"Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations."