Q http://volcanoes.usgs.gov/hazards/gas/climate.php Yearly CO2 emitters; Billion metric tons per year (Gt/y) Global volcanic emissions (highest preferred estimate); 0.26 Anthropogenic CO2 in 2010; 33.6 Light-duty vehicles (cars/trucks) ; 3.0 Approximately 24 1000-megawatt coal-fired power stations *; 0.22 Argentina ; 0.18 Pakistan ; 0.16 Saudi Arabia ; 0.46 CO2 emission events Mount St. Helens, 18 May 1980; 0.01 Gt Mount Pinatubo, 15 June 1991 ; 0.05 Gt Number of Pinatubo-equivalent eruptions equal to annual anthropogenic CO2; 700 Number of Mount St. Helens-equivalent eruptions equal to annual anthropogenic CO2; 3500 UQ
But, how about Hydrogen Bomb??? Have all countries agreed yet to never ever use their H-Bombs? If not, ... https://en.wikipedia.org/wiki/Castle_Bravo " Castle Bravo was the code name given to the first United States test of a dry fuel hydrogen bomb, detonated on March 1, 1954, at Bikini Atoll, Marshall Islands, as the first test of Operation Castle. "
The argument from deniers has retreated to the "it's not a problem anyway" stage, which stage I predicted on this very forum over two years ago. You are correct from a risk management perspective. The greater the uncertainty around the probability of a negative outcome the greater should be the policy caution. This principle is why we pull something from the store shelves right away when it appears it may be hurting people.