Australian Broadcasting Corporation: The Greens are attempting to break the political deadlock over emissions trading by suggesting an interim two-year scheme with a fixed price on carbon. Greens Senator Christine Milne is writing to the Government and the Opposition proposing a carbon price of $20 a tonne. Opposition Leader Tony Abbott will soon unveil his plan to cut greenhouse gases without a trading scheme or carbon tax and there is little, if any, prospect of the Government getting its legislation through the …