Volcanoes Emit more CO2 than Mankind

This is a pervasive myth that continues to circulate. The idea that volcanoes put out more CO2 than mankind through human industrial output is patently false. Volcanoes put out around 0.2 Gt (200 million tons of CO2). The facts are clear and measured. As of 2010, humans put out on average of around 27Gt (Twenty Seven ‘Gigatons’) of CO2 per year. That’s 2,700 million tons compared to natural cycles 200 million ton output.

Stromboli volcano eruption
Strombolian Eruption

Comparison of CO2 emissions from volcanoes vs. human activities.

Human activities release more than 130 times the amount of CO2 emitted by volcanoes–the equivalent of more than 8,000 additional volcanoes like Kilauea (Kilauea emits about 3.3 million tonnes/year)! (Gerlach et. al., 2002)

Scientists have calculated volcanoes emit between about 130-230 million tonnes (145-255 million tons) of CO2 into the atmosphere every year (Gerlach, 1991). This estimate includes both subaerial and submarine volcanoes, about in equal amounts. Emissions of CO2 by human activities, including fossil fuel burning, cement production, and gas flaring, amount to about 27 billion tonnes per year (30 billion tons) [ ( Marland, et al., 2006) – The reference gives the amount of released carbon (C), rather than CO2, through 2003.].

Source: US Geological Survey

Natural Cycles