Volcanoes

Frank O'Dwyer tells me that the claim made in the Great Global Warming Swindle about volcanoes releasing more CO₂ into the atmosphere than humans is wrong. I've not been able to make a lot of progress in getting to the bottom of either Frank's claim, or the GGWS one, but I did come across something quite interesting.

74,000 years ago, the Toba volcano erupted in a VEI 7 explosion that pumped more than 10,000 times as much CO2 into the air as Mt. St. Helens did. At the maximum, Mt. St. Helens was giving off 22,000,000 kg of C02 daily, so Toba was putting out at least 22 billion kg per day. The ash cloud was so thick that it caused cooling that nearly wiped out the human race.

There are indications in the ice core records that show the cooling from Toba, but where is the global warming that should have resulted from all the CO2 put into the atmosphere? According to what I've read, the CO2 should have remained in the air long after the ash settled and that should have caused at least a warming spike, but there's no sign of extraordinary warming in the climate records. Shouldn't there always be a cooling/warming cycle after a volcano erupts? Cooling from the ash cloud, warming from the CO2 that lingers?

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