Prime Minister Anthony Albanese should call the bluff. Electoral arithmetic is on his side.

The Greens executed the threat in 2007 and 2008. In the Senate they voted twice with the Liberal Party to do down then Labor prime minister Kevin Rudd's legislation to address "the greatest moral challenge of our generation". And a decade of climate inaction followed.

In 2007 and 2008, Greens leader Bob Brown allowed the futile pursuit of the perfect to defeat the achievement of the good. It was shameful.

And as we head into the first week of parliamentary sittings of the new Labor government, Greens leader Adam Bandt is doing the same thing: threatening to vote against Labor's target of 43 per cent reduction in greenhouse gases because he thinks it is not good enough.

But surely it is better than not legislating for anything at all.

In 2008, Rudd failed to win either the tactical or strategic game. Albanese is in a better position. He should do what Rudd did not do: tell the Greens that if they block the legislation there will be a double dissolution, at which the Greens will lose ground - and a lot of it.

In 2022 that tactic and the strategy of following through with it is even more compelling because the electoral arithmetic and the voting system have changed.

Albanese should tell the Greens that if they do not pass the legislation (even after he concedes that 43 per cent is a floor not a target), Labor would call an immediate double dissolution at which Labor would not list the Greens in its preference list in the Senate and in the representatives would put them below the Liberals and only just ahead of the mad right.

Look at the arithmetic. Fully half of the 16 Green members of the Senate and House of Representatives owe their positions to Labor preferences. If Labor withdraws those preferences the Greens representation in the Parliament would be halved.

A brief explanation of Senate preferences is warranted here.

Most Australians imagine that preferences of minor parties are the only ones that matter because in the House of Representatives they flow to one or other of the major parties and determine which one or other of those candidates gets elected.

But in the Senate, it is different.

The easiest way to explain the Senate position in which six senators are elected from each state is as follows. Candidates get elected on receiving a quota of one-seventh plus one (because if six candidates get that, no other candidate can beat them). But no major party gets an exact quota of votes for the seat or seats they win. There is always an over-quota. Typically, the major parties get two-point-something of a quota in each state. The "point-something" is not lost. It is distributed on preferences with a discount to account for the senators of that party already elected.

The preferences of major parties in the Senate invariably go to deciding who gets the sixth (or last) Senate seat in each state. In the 2019 and 2022 elections at which the current crop of senators got elected, at least five of the 12 Green senators relied on Labor preferences to get elected.

In the house all three newly elected Greens owed their seats to Labor preferences.

In total eight, perhaps nine, of the 16 Green members of Parliament owe their positions to Labor preferences. The Australian Electoral Commission figures I crunched show as much.

If Labor put sundry environmental and left candidates like Sustainable Australia, Animal Justice and the Cannabis party, and perhaps the odd Liberal, on their Senate how-to-vote cards and not put the Greens on it, it would be unlikely for a Green to win a seat in an ordinary Senate election. In a double dissolution it would be near impossible for the Greens to get two of the 12 seats in any state.

READ MORE:

So, Albanese should make it very clear that if the Greens side with the Liberals to vote against climate action they would be shooting themselves in the foot - blasting away eight of their 16 members of Parliament. In any event other parties on the left have better environmental credentials than the Greens.

Certainly, Sustainable Australia with its vigorous policy to reduce or eliminate population growth is better environmentally credentialed than the Greens who will not go there. Indeed, the debate about climate and the recent State of the Environment report almost totally fail to mention the underlying cause of the problem: population growth and in Australia high immigration which causes koala and other habitat to be trashed for housing.

Bandt may rabbit on about how Labor got just 31 per cent of the vote so it should not always get its way.

But the totality of the Australian vote suggests that a great majority of Australian voters want climate action. About three times as many people voted for Labor's promise of a 43 per cent reduction than the Greens' 75 per cent.

The important thing is for the Greens not to jeopardise at least a start which can be improved later.

If it does so, Labor would be well-justified in calling a double dissolution and using its how-to-vote cards to consign at least eight of the 16 Greens to unelectability.

It would be in Rudd's phrase the "morally right thing" to do.

So just when the Greens think they are in the most powerful position than they have ever been in, they are in fact at their most vulnerable if they try to over-egg their pudding.