On Dec 9, 8:16*pm, Roger Chapman wrote:


What's different about AGW?

The huge amount of compelling evidence.

I would call it circumstantial, rather than compelling.


For there to have been no AGW you would have to accept either that
mankind had nothing to do with the 50% increase in CO2 concentrations or
that CO2 is not a greenhouse gas.

CO2 is a greenhouse gas, lets put that one to bed.

So it reduces to "For there to have been no AGW you would have to
accept that mankind had nothing to do with the 50% increase in CO2
concentrations"

Why? Of course mankind is responsible for CO2, along with many other
emissions. You're making assumptions about the effect of CO2,
specifically that the measured increase is directly responsible for
any warming.

How long have accurate CO2 measurements been taken?

How reliable is the proxy data for historic CO2 levels?

MBQ