Blockbuster: Planetary temperature controls CO2 levels — not humans « JoNova: Science, carbon, climate and tax: "The largest increases year-to-year occurred when the world warmed fastest due to El Nino conditions. The smallest increases correlated with volcanoes which pump dust up into the atmosphere and keep the world cooler for a while. In other words, temperature controls CO2 levels on a yearly time-scale, and according to Salby, man-made emissions have little effect.I posted a while ago about this but didn't link the excellent video of the talk -- there, fixed. (Actually, the talk is excellent but the video has some issues here and there.)
The climate models assume that most of the rise in CO2 (from 280 ppmv in1780 to 392 ppmv today) was due to industrialization and fossil fuel use. But the globe has been warming during that period (in fact since the depths of the Little Ice Age around 1680), so warmer conditions could be the reason that CO2 has been rising.
Salby does not dispute that some of the rise in CO2 levels is due to man-made emissions, but found that temperature alone explains about 80% of the variation in CO2 levels."
Unfortunately, embedding is not enabled for the video so you'll have to click. You won't be sorry.