"Dan" wrote:



But we are now conducting a massive, uncontrolled experiment on the only
atmosphere we have. Should we just let it ride and see what happens?

We *have* been living in such an experiment since humankind has
inhabited this planet.

Yep, and sometimes the "experiment" has produced mass extinctions. We're
fortunate to be living in an epoch of mild climate that should last for a
long time. Why would we want to mess with it?

What's happening now is different. This is a massive artificial addition of
CO2, unprecedented for its suddenness. There's been nothing like it for at
least 800,000 years, probably much longer.

One of the assumptions of the pro-AGW theory is
that the the only variable is human activity

Absolutely not. Where'd you get that idea?

In fact, that is one of the red herrings used by the disinformation
lobbyists. They like to say that every wiggle downward in temperature proves
that CO2 rise isn't causing warming because the CO2 increase is steady and
warming isn't. Scientists know that a lot of things influence climate
annually, but the overall *trend* is up and no cause but a 35% rise in the
CO2 level accounts for it.

-- and when certain
amplifying or mitigating data is considered (solar variation, volcanic
activity, deep ocean heat sink, atmospheric particulate matter of lack
thereof), it is always considered in isolation -- never in aggregate
in any of the IPCC or related publications.

Nope. All those things are considered. The IPCC concentrates on the AGHG
forcing component because that is the variable humans can change. Do you
really believe the scientists who contributed to the IPCC don't know about
those things?