The Greens have been enjoying a favourable press in recent months including suggestions they might dramatically improve their showing in the anticipated 2007 elections. I think that is unlikely, and one reason for saying that is the Green Party is hurt more by the first past the post system than are either the NDP or the Liberals, their natural competitors for small 'g' green votes.
I used my forecasting model to measure this using the results of the 2006 federal election. The results can be seen in the table below (click on the graphic to enlarge):
What I did was reverse the vote shares between the Greens and the NDP in the one case, the Greens and the Liberals in the other. That is I assumed that for every province, the Greens would get what the NDP actually won while the NDP would receive the same vote share as the Greens actual 2006 share, and I did the same in a second exercise involving the Green and Liberal votes.
What I discovered is that with exactly the same vote share as the NDP actually had in 2006 the Greens would have won only 8 seats, compared to the NDP's 29 (a deficit of 21 seats). If they had the Liberal vote share they would have won 76 seats compared to the Liberals actual 103 (as deficit of 27 seats).
This tells us the Greens have a far more dispersed vote pattern than either the Liberals or the NDP and that a Green vote is more likely to be cast for a losing candidate, even if the party were to succeed in dramatically increasing its share of the popular vote.