The time has come to count the cost, and count how little it really is. Ten billion dollars would buy Indonesia's forests whose bushfires are 20 per cent of the planet's annual carbon increase, and $100,000 - surely - each year would police the firebugs with helicopter gunships, parachuting SWAT teams and Elvises dropping water. That's 20 per cent of global warming gone for the price of eight days of the Afghan war.

Ten billion dollars more would keep comfortable for 15 years the 10,000 coal miners we should probably stop mining Australian coal - in five years' time or so - till a coal-smoke-disposal system is perfected. Solar, wind and hot-rocks power could give us our electricity till then, once people start putting solar mirrors on their roofs.

Is this so much money? It would cost each Australian taxpayer $7 a week for four years to bring down the world's carbon output by 25 per cent, or $4 a week to buy the next few fighter bombers and submarines in the same time frame.

Is that so much money? A choc-top and a small popcorn sacrificed each week, to help save the world?

Similar money could pay certain fishermen to stop fishing certain rivers, say, three per nation per year, for 18 months or two years so the world fish stocks replenish.

Or building dykes in the Maldives and Bangladesh. Or putting half the Darling under clear plastic wrap to stop evaporating.

This is the kind of thing tax is for. Tax is there to bring civilisation, schools, hospitals, universities, Apollo missions, church repairs, tsunami relief, opera houses, just wars - and it's idiotic for the Liberals to say in a time of international catastrophe it should come down.

Tax is a cost, that's all. It's the cost, in the main, of keeping us safe. Other costs we don't seem to mind: the $15 a week we pay, in product price, for television advertising, the $15 a week for crossing the Harbour Bridge, the $200 a week - some weeks - for parking in town.

Yet $15 or $20 a week to save the world and replenish the fish in it is an outrageous import we shouldn't contemplate.

We each pay one dollar a week, perhaps, for the various CEOs of Telstra, Qantas, Woolworth's, Wilson Parking, Sydney Airport and so on who do little work for their millions a year. We each pay in road tolls, bus fares, ferry fares and parking fees more each week, on average, than it would cost to save the world.

Yet the Liberals say the various methods proposed to do it - to save the Barrier Reef and prevent the displacement by sea rise of 300 million people - are "unaffordable" at $20 a week, the kind of money we pay each week for useless CEOs, or choc-tops, or cinema tickets, or the Murdoch newspapers.

Money is money, that's all. And we can spend one billion dollars a week of it protecting the Karzai Brothers from arrest and conviction for illegal drug-running, or stopping the bush fires that are choking the planet, restoring the fish and pursuing hot-rocks technology to the point where it replaces coal.

We can spend money uselessly, or fruitfully. Naturally we choose the former.

The same 'tax dollar' that props up the murderous bull-ant Netanyahu could be sucking up the Shoalhaven (as one good idea lately suggests) and spewing it into the Murrumbidgee and replenishing at the Murray's end the Coorong and returning the pelicans (like Mr Percival) to that natural wonder. Or cleansing the waters of the Third World; or putting the right sort of light bulbs in light sockets everywhere in the world, and bringing down carbon that way.

It's only money and there's actually enough of it to fix things, money that is misdirected to greedy bastards who don't need it, money the planet could use.

And a World Salvation Impost of $15 a week on the West, which is 700 billion a year, could sort out most of these problems, or try to, in a decade or so.

But the Big Polluters call it all "unaffordable" and demand lower taxes for their massive delay in solving things, and paying their CEOs nine million a year for failing to solve them.

I'm old, and I'm getting a little tired of this innumerate assault on the obvious. Tax, more tax, though not much tax, and a cap on the wages of CEOs to four times that of the US President would solve most of it, or give us a fair chance to solve it, which Carbon Trading will probably never do, any more than taxing cigarettes will wipe out smoking.

It hasn't so far.

I called Penny Wong "the Minister for Not Yet" on Q&A a few months back, and I have proved since then to be right. But prodding and mocking Malcolm, the best friend her fool scheme had, and humiliating his faction and his Party she drove him out of office and politics, and the parliamentary argument back to the oh-no-no-another-tax kindergarten oratory of my new friend Tony Abbott, an infantile denier of most things, including arithmetic.

She has done very badly, in short, as I knew she would, so ignorant she seemed that night of everything.

I ask for her sacking now for her total failure to get her intended legislation through, and her apology for messing the planet around.

Or perhaps you disagree.