 The date is circled on the calendar. The polling card is on the mantelpiece, along with all the parties' propaganda. Their population analysis seems to have told them that if I live in the south of Scotland I must be either a farmer or an elderly person in need of healthcare. Well. I'm a floating voter. Floating on a great big lily pad of indifference, knowing that round these parts, it's a two-horse race. One of the frontrunners is greener than the other so I'll probably vote for them. What of my second vote? Tactical? Is there any point voting for a smaller, greener party? Would we be better under aV? Let's leave that one. Instead, a round-up the main parties and the key environmental issues.  First, the Conservatives. On the positive side they support city cycle schemes, a thumbs-up for a carbon-capture trial at Longannet, a requirement for public bodies to draw up targets to reduce their energy consumption and, er, that's about it.  The Lib Dems get a pat on the back (they don't get many these days) for pledging GBP250 million to insulate homes. Further gold stars are awarded for promoting the use of electric vehicles but boos from the crowd for supporting more road-building. Still, they are in favour of the notion that 100 per cent of Scotland's electricity should  