Who can really blame the Liberal candidate for Wakefield Tom Zorich for not understanding his party's so called Direct Action Plan to address climate change – nobody else does.

This is the plan that not a single Australian economist or industry group supports. Only last month the Australian Industry Group was reportedly saying that it prefers emissions trading because direct action is still only "a work in progress". In the week that people start voting at pre-polls, we are still to see any costing or analysis of the plan.

Shadow Climate Change Minister Greg Hunt says the plan is well documented, but even senior Liberal Party politicians are confused. Earlier this year Joe Hockey said that businesses which suffer as a result of repealing the carbon pricing scheme will be compensated, only to change his tune a few hours later. And Tony Abbott has said that penalties will be applied to firms exceeding some baseline level, only to be later corrected by Greg Hunt.

There are numerous fundamental failures of the Direct Action Sham, but here are the top three.

First, the fact that Direct Action cannot be scaled up, is unlikely to reduce emissions even by 5%, is underfunded, and cannot realistically achieve more is its overwhelming and fundamental failure. At a time when we have the International Monetary Fund boss Christine Lagarde saying, “Unless we take action on climate change future generations will be roasted, toasted fried and grilled” to try to suggest that an Australian target of just -5% by 2020 is acceptable is a lie. As the rest of the world move towards a legally binding global treaty and the second commitment period of the Kyoto Protocol, such a lax target from one of the world’s largest per capita emitters will become untenable and indefensible.

The Direct Action Sham is in essence a massive ‘competitive grant programme’ which seeks to reduce emissions by companies putting in ‘tenders’ for actions that reduce greenhouse gas emissions and the government then taxing us to pay those companies which submit the best bids based on multiple but poorly specified criteria.

The second showstopper is that the Coalition expects more than 60% of the abatement to come from soil carbon – but the science to back this up is not yet solid, so this abatement would not be recognised in international treaties.

The third is that assessing the tenders to ensure that they involve genuine reductions in emissions is fraught with difficulty. As Malcolm Turnbull has said, “if a scheme operates whereby the government pays the firm to reduce its emissions intensity … there is firstly going to be a substantial and contentious debate about what the correct baseline is, and then whether it will actually be reduced…Arguments of considerable ferocity will arise as to whether a new piece of equipment would have been bought anyway, with the risk that the government ends up funnelling billions of dollars to companies to subsidise their profit without achieving any real additional cuts in emissions.”

The Coalition cannot hide from the fact that Direct Action is a slogan, not a policy.

We are living in a climate change emergency. As recognised by John Howard and Malcolm Turnbull, carbon pricing is essential. Tony Abbott deserves to lose the election on this failure alone. It is not just policy failure, it is morally reprehensible and cowardly to knowingly make life worse for all who come after us.

Senator Christine Milne is the leader of The Australian Greens.