Well jopo, you are nearly 20 years out of date. We have gone from expecting, in 1995, to find the signals of AGW, based on fundamental greenhouse gas physics and CO2 emissions levels, and seeing signs, but not yet having the data and models to be definitive about that; to now, when it is clear this is human caused global warming.
We've learnt a lot in 20 years.
Here's what the IPCC said in the 2005 2nd assessment report. It is consistent with what you posted from that 1996 email.
"Our ability to quantify the human influence on global
climate is currently limited because the expected
signal is still emerging from the noise of natural
variability, and because there are uncertainties in key
factors. These include the magnitude and patterns of
long term natural variability and the time-evolving
pattern of forcing by, and response to, changes in
concentrations of greenhouse gases and aerosols, and
land surface changes. Nevertheless, the balance of
evidence suggests that there is a discernible human
influence on global climate."
Here's what they say now:
Compared to AR4, more detailed and longer observations and improved climate models now enable the attribution of a human contribution to detected changes in more climate system components.
Human influence on the climate system is clear. This is evident from the increasing greenhouse gas concentrations in the atmosphere, positive radiative forcing, observed warming, and understanding of the climate system.
"Human influence has been detected in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, in global mean sea level rise, and in changes in some climate extremes. This evidence for human influence has grown since AR4. It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.
