Comment Re:Different thing (Score 1) 776
Humans contribute 2% of greenhouse gas emissions globally.*
This page does not address the relative amounts of natural and human-caused greenhouse gas emissions.
The 2% figure occurs in the pie diagram showing different types of greenhouse gases, all of them expelled into the atmosphere by human activities, of which the hydrofluorocarbons (HFC's) and related synthetic compounds make up 2%. The 2% figure is repeated below figure 4 for "human-made gases", but this appears to be a rather ill-chosen way of indicated that these compounds do not occur naturally at all, while the other greenhouse gases in the pie chart also have natural sources. But again, the entire page only talks about the composition of man-made greenhouse emissions, and does not make any claims how big these are compared to gases emitted by natural processes.
I have been looking for more information on the relative contributions of natural and artificial CO2 emissions. So far the most succinct description I found is this: "How do human CO2 emissions compare to natural CO2 emissions?".