How tree leaves caused a climate change during the Devonian

I didn’t understand the relation between the silicates and the CO2 fixation. All I found about this is <a href="http://en.wikipedia.org/wiki/Carbonate%E2%80%93silicate_cycle" rel="nofollow">http://en.wikipedia.org/wiki/Carbonate%E2%80%93silicate_cycl...</a> . Can someone with more geological/chemical background say if this is the correct process?