If you think the politics of choosing food can be tricky, imagine what agreeing on national and international policy can be like. Fortunately, we invented parliaments to consider exactly these questions for us. Unfortunately, sometimes, like a group of hungry friends stuck squabbling on a street corner, parliamentarians struggle to make clear decisions and act on them.

Take climate policy for example. Is climate change such an urgent problem that we should "just get on and do something"? Or is it such an important problem that we need to make sure we get our goals and our mechanisms just right? Should we make policy on the run or should we hasten slowly to provide clear goals and policy certainty?

Not only do well-meaning people disagree with each other on these questions, well-meaning people often disagree with themselves on these questions.

For more than 20 years now, the Australian political and business elite have been unable to act on the clear scientific evidence of the risks of climate change and the clear economic evidence that taxing pollution provided a simple, and lucrative, solution. The Turnbull government has tied itself in bigger knots than most. John Howard invented the renewable energy target that his Coalition now rages against. John Howard, Brendan Nelson, Malcolm Turnbull and Tony Abbott all spent time supporting, and opposing, emissions trading. Abbott once even expressed a preference for a simple carbon tax. Josh Frydenberg was briefly a fan of an emissions intensity scheme until Cory Bernardi convinced him otherwise and now the Coalition may, or may not, support a clean energy target. When it comes to climate policy, the Coalition have been pretty fussy eaters.

For a government that opposes carbon taxes, emissions trading and expanding the RET or an EIS, a CET may well be the best way forward. But whether the Coalition can build both public and parliamentary support for such a scheme is yet to be determined. It is one thing to agree to have Mexican food for dinner; it's another to decide how much chilli to put in.

Chief Scientist Professor Alan Finkel proposed the design principles of a clean energy target with the specific intention of helping the Coalition navigate around its own self-inflicted dietary constraints. It's a strange task to set for a chief scientist, but he did it pretty well.

But while Finkel laid out a new buffet for the Coalition party room to choose from, he deliberately left the task of selecting the combination of ingredients, and how many tacos to make, to the politicians. Some of them are clearly hungrier than others, some of them want plenty of chilli, and some of them seem to just want big dollops of sour cream.

The big decisions that need to be made to turn the idea of a CET into a concrete policy proposal revolve around the definition of what constitutes "clean energy", the target for how much clean energy is to be generated and the size of the obligations, if any, that renewable energy generators will shoulder to build energy storage capacity.

While there is an understandable amount of interest in whether the definition of "clean energy" will stretch to include gas, coal with carbon capture and storage, or just good old-fashioned coal-fired power stations, it is difficult, if not impossible, to evaluate such a scheme by looking at individual components in isolation. Some people can handle more chili if it comes with more cream.

Under the structure Finkel proposed, the further below the clean energy threshold a particular electricity generator is, the more credits it would receive. So if the threshold is just higher than the most efficient gas-fired power stations, then those plants would receive a modest amount of credits while wind and solar would receive a lot more. While some, including me, might argue there is no good reason to provide investors with any incentive to build new gas-fired plants, if the CET's overall target was ambitious enough that it led to the rapid closure of coal-fired power stations, it might be worth considering, especially as a small incentive to build gas-fired power stations probably wouldn't lead to any actually being built.

The same balancing act emerges with the proposal for the owners of renewables to be required to invest in energy storage at the same time. If all sources of electricity generation, including coal and gas-fired plants that shut down for scheduled and unscheduled maintenance, were required to invest in a modest amount of storage capacity, the CET could help the grid evolve to meet the rapidly changes in technology. But if very large storage obligations are imposed only on new investments in wind and solar, the CET could be used as a tool to stifle that same transition.

While the Coalition party room is yet to decide how hungry it is to drive real investment in renewables, the final decision about both the ambition, and the design features, of climate policy will ultimately be decided by the Senate, not the government. If the Coalition can stomach a model that is sufficiently ambitious and well-designed that Labor, the Greens or enough crossbenchers can stomach it, it may well pass into law before the next election.

But if the climate sceptics in the Coalition win the day again the opposition, the crossbench may decide it is worth waiting for a tastier feed rather than simply bite down on whatever the government serves up. Sometimes, nothing is better than just anything.

The Australia Institute's inaugural national energy emissions audit, compiled by respected analyst Hugh Saddler, revealed that the feared "business as usual" scenario modelled by Finkel isn't really likely as it excludes state renewables schemes. A number of big states are implementing very reasonable and obtainable renewable targets, which would achieve basically the same clean energy mix as modelled in Finkel's proposed CET.

And there's the rub. While the politics of Queensland's Liberal National Party has our country subsidising the enormous Adani coal mine, the science of climate change says we must urgently act to reduce emissions. But if we rush a poorly designed scheme through Parliament, we might encourage the construction of new gas and even coal-fired power stations that would lock in higher emissions for decades to come.

Back in 2009, when the Greens voted down Kevin Rudd's carbon pollution reduction scheme, they argued that locking in failure was worse than appearing to do something. Having raged against the Greens' decision for the last seven years, Labor may soon end up making exactly the same argument – and I may well end up agreeing with them, too. Or not.

Richard Denniss is The Australia Institute's chief economist. Twitter: @RDNS_TAI