The other thing for me is trusting them to keep us competitive in an ever more challenging global economy. If we’re too idealistic and too ahead of our time we’ll run out of money – we need a stronger balance of trade to pay the bills.
the green party won’t be winning the GE, but a vote for them is a message to the other parties that there are votes in green/social policies.
if you’ve got lefty tendencies, voting green is roughly twelfty-bijillion times more useful than not voting because you can’t find a party that exactly agrees with how you think the country should be run.