Original sentence: A significantly higher sensitivity to solar forcing would make early 20C temperature change inexplicable.A summary of climate research may be found in the IPCC assessment reports; opinions as to the degree of consensus are discussed at scientific opinion on climate change.Climate models do not incorporate the indirect solar forcing through modulation of cosmic ray flux (increased solar activity reduces cosmic ray flux and is speculated to modify cloud cover).In the 1995 second assessment report (SAR) the IPCC made the widely quoted statement that "The balance of evidence suggests a discernible human influence on global climate”.Scientists Willie Soon and Richard Lindzen say that there is insufficient proof of the recent attribution as yet.The current view of the IPCC can be summed up roughly as: most of the warming observed over the last 50 years is attributable to human activities.Though this is still unclear
Edited sentence: A summary of climate research may be found in the IPCC assessment reports; the degree of consensus is discussed at scientific opinion on climate change.Global climate models do not incorporate the indirect solar forcing through modulation of cosmic ray flux (increased solar activity reduces cosmic ray flux and is speculated to modify cloud cover).In the 1995 second assessment report (SAR) the  IPCC made the widely quoted statement that "The balance of evidence suggests a discernible human influence on global climate”.Indeed, a significantly higher sensitivity to solar forcing would make early 20C temperature change inexplicable.Scientists Willie Soon and Richard Lindzen say that there is insufficient proof of the recent attribution as yet - though they have not written papers showing this.The current best answer is, roughly, most of the warming observed over the last 50 years is attributable to human activities