CO2 from Volcano's vs CO2 from humans

[Quixote1818]

Its funny how when I ask people if they believe one volcano can impact temperatures and influence weather they often say "Of course". But tell them that 365 days out of the year, billions of cars and thousands of factories around the world are pumping chemicals into the atmosphere and are changing the climate; for some reason that becomes far fetched. Even with the Earth getting hotter each year as has been predicted by NASA and NOAA. This got me interested in the actual numbers which stunned me!


Snip>
Our studies show that globally, volcanoes on land and under the sea release a total of about 200 million tonnes of CO2 annually.

This seems like a huge amount of CO2, but a visit to the U.S. Department of Energy's Carbon Dioxide Information Analysis Center (CDIAC) website (http://cdiac.ornl.gov/) helps anyone armed with a handheld calculator and a high school chemistry text put the volcanic CO2 tally into perspective. Because while 200 million tonnes of CO2 is large, the global fossil fuel CO2 emissions for 2003 tipped the scales at 26.8 billion tonnes. Thus, not only does volcanic CO2 not dwarf that of human activity, it actually comprises less than 1 percent of that value.

http://hvo.wr.usgs.gov/volcanowatch/2007/07_02_15.html

[petronius]

1. One caveat - volcanoes mainly affect climate through sulfur dioxide emissions,

which become sulfate aerosols in subsequent months. The aerosols generally have a cooling effect, rather than the warming of CO2.

But you're right - it is silly to accept at face-value the fact the single (even catastrophic) eruptions can have global consequences, while not even considering that the much larger anthropogenic outputs might as well...

[Quixote1818]

2. Good point. Also the dust clouds from volcano's can cool the planet even more. nt

[petronius]

8. Yes. Although I'm pretty sure that dust tends to settle out fairly quickly

and not get lifted quite as high in the atmosphere. Sulfates from a low-latitude explosive eruption reach the stratosphere, and encircle the globe for months or years after the event.

But at a more local scale and for a shorter time, dust would definitely cast a pall.

I seem to recall there was a popular denier claim that one volcanic eruption dwarfed all anthropogenic GHG/aerosol emissions. It seems to have gone away for some reason (perhaps because it's blatantly untrue)...

[Arctic Dave]

3. I've tried using the same mental image with people.

I asked them imagine every car exhaust, smoke stack, heating furnace, industrial process going twenty four seven. Occasionally I will get someone to reconsider there position.

[Tatersbrowning]

4. ERM,,?

The chart at your link actually shows 8365 tons per annum globally from fossil fuels. That's significantly lower than 200 million tons.

http://cdiac.ornl.gov/ftp/ndp030/global.1751_2007.ems

[Quixote1818]

6. That chart is in Millions of tons. That would be 8365 X a Million

Also the 200 million tons is what volcano's produce. Try billions for humans.

[petronius]

9. Note also that the table is giving megatons of carbon, not CO2

A kg of carbon corresponds to ~3.7 kg of carbon dioxide...

Welcome to DU! :hi:

[NuclearDem]

5. I remember a website someone showed me...

Back after the Icelandic volcano eruption showing the comparison of CO2 launched from the volcano versus the CO2 that wasn't emitted due to the aircraft groundings...

[wtmusic]

7. Almost all CO2 outgassing from volcanoes and seltzer springs

is offset by carbon burial:

"The total amount of carbon in the surface carbon reservoirs on long time scales is determined by the balance between outgassing (via volcanoes and seltzer springs) from the solid
Earth and burial back into Earth's crust (Berner, 2004). CO2 outgassing occurs via metamorphism of ocean crust as it is subducted beneath moving continental plates. Burial is
primarily via the chemical weathering of rocks with deposition of carbonates on the ocean floor, but to a less extent via burial of organic matter, some of which eventually may form fossil fuels. "

http://columbia.us1.list-manage.com/track/click?u=0ebaeb14fdbf5dc65289113c1&id=82345f4c72&e=5bbc9310b8

There is believed to be a net positive imbalance, but one so small it would take 1 million years to raise atmospheric carbon by 100 ppm.

Humans have achieved that in 100 years.

[Ozymanithrax]

10. You see God causes volcanoes to erupt...

so it is really the invisible hand of God causing the change in climate after a volcano erupts.

People drive cars.
People don't have invisible hands.
Ergo sum...
People do not affect climate.

If you don't think about it, it makes perfect sense.

[Warren DeMontague]

11. Volcanos don't have nearly as good PR departments as oil companies.

Much less lobbyists.