On Oct 25, 1:48*am, "Peter Webb"
wrote:

It doesn't even define what "global warming" is, and nor has anybody in this
thread.

What is global warming?

It's an increase in the worldwide mean temperature, due to increased
levels of greenhouse gases in the atmosphere.

We know, from those measurements in Hawai'i, that the proportion of
carbon dioxide in the atmosphere has increased.

If the worldwide mean temperature has increased, when you average out
over things like the La Nina/El Nino cycle, then there is reason to
suspect that AGW has taken place (the increase in carbon dioxide
levels _is_ anthropogenic).

Of course, one still has to eliminate other causes, but IIRC, sunspots
have been going the wrong way to cause warming - we've had a quiet sun
recently.

John Savard