[Gaffer]

If I were confronted with the same situation, I'd make two statements:

1) Mt. Pinatubo's eruption in the Philippines introduced into our atmosphere more C02, particulates, chemicals and generally all round nasty pollutants than ALL of mankind's industrial existence (they can go Google their NASA friend and see the satellite pictures in all their multicolor splendor), and

2) Will, just one, any of them tell me the optimum temperature for the planet and why that should be the "goal" which drives all other of our endeavors?

[palmer]

Mt. Pinatubo's eruption in the Philippines introduced into our atmosphere more C02, particulates, chemicals and generally all round nasty pollutants than ALL of mankind's industrial existence

Not even close to true. Mount Pinatubo blew out 42Mt of CO2 and mankind creates 7100Mt a year (more now, that's a couple year old number).