Mary

that on current tecglonohy the 'tree' captures 1 tonne per day, but it is 'conceivable' that it could be increased to 10, and the 100,000 trees figure is based on this. The cost of building the things is estimated at $2bn and then the cost of capturing the CO2 'could drop to as low as' $30/tonne, (much lower than the figure in Roger's paper) so could only cost $30M per day! The cost of storing the stuff underground is not even mentioned. And all this is based on the estimates of the proponents of these schemes.