Skeptical Science

November 04, 2016

US Passenger Vehicle Emissions Comparable to 1980 Mt. St Helens  Eruption Occurring Every 3 Days



Joel_Huberman at 00:51 AM on 6 November, 2016

Interestingly, the Large Igneous Provinces (LIPs; massive, long-time volcanic activity) that have been associated with major extinction events in our planet's geologic/biologic history have released multiple thousands of gigatons of CO2 over their lifetimes. If we humans are releasing 46 gigatons per year, I suspect that we're emitting CO2 at a rate comparable to that of LIPs--natural events that wiped out large portions of extant species.

Tom Curtis at 01:43 AM on 6 November, 2016

Joel_Huberman @1, your source suggests the Siberian Traps released 30,000 GtC of CO2 over the period of its erruption, ie, over a period of over a million years, representing an annual emission rate of around 0.03 GtC per annum.  In contrast, since 1850 humans have emitted 560 GtC at a mean annual rate of 3.4 GtC.  Since 1965 (ie, over the last 50 years for which we have published data), we have emitted 370 GtC at 7.4 GtC per annum.  Since 2010 the average annual emission rate has exceeded 10 GtC per annum.  In short, we are emitting CO2 at rates that far exceed those during the deposition of large igneous provinces.

william at 03:59 AM on 6 November, 2016

The graphic was great.  None of the deniers will read the text and few would understand if they did.  How about two more graphics.  a) The total yearly emissions from all geological sources vs the total yearly emissions of us and b) Our yearly rate of emissions vs the rate of emissions during the laying down of the Siberian traps.  Then we can send this to our denier friends in a form they can comprehend.

nigelj at 06:25 AM on 6 November, 2016

William @3, I totally agree. However you can imagine what the deniers will say. "Volcanic emissions of CO2 in recent decades are underestimated, the figures are junk science concocted by people promoting big government (or some other ulterior motive, or grand and completely silly conspiracy theory).


bozzza at 18:19 PM on 6 November, 2016

All you need is a graph on global sea ice... highlighting 2016 against the sattelite record.

jg at 05:18 AM on 7 November, 2016

Hi William, I like your suggestions and will look into drawing the 2nd. Your first suggestion my be covered already by one of our illustrations here:

Human vs natural CO2 emissions

The first diagram in this post is based on the graphic I've linked to.