Before then, they could expect to pay at least 1% more across the board for everything they bought, and much more for anything affected by big-hit ETS costs, he said.
Mr O'Leary said his company would, on average, add another 30% to the price of its coal to cover the direct ETS costs and the additional cost of fuel, electricity and transport. That would push the price of coal from $84 a tonne to nearly $110 a tonne.
But, "just like with other businesses", those costs would likely increase as transport and energy companies, and all businesses that used them, came to terms with the true cost of the ETS.
Companies could only estimate their costs based on the Government's ETS formula and the additional costs they thought would be passed on by their suppliers.
"That's the problem here. People can still only estimate the new cost, because they really have to wait and see how the other costs on their suppliers flow through to what they are charged.
"There's a huge risk to the economy here. Put it this way: when I told my team that we'd have to put up prices, they came back and said they'd have to ask for a pay rise. That's an additional cost that I bet will be worn by businesses everywhere."
There were other fears. Treasury warned last year that the cost of carbon could rise to $100 a tonne.
"Just think of the effect if that happens, when it's $12.50 at the moment."
Kai Point Coal supplied Fonterra and Silver Fern Farms. Mr O'Leary worried that costs he had to "collect for the Government" would affect food prices.
"Coal has the advantage as still one of the cheapest forms of energy there is. But the cost is rising, and not just to people who use it to heat their home, who are sometimes the people with the least amount of money to waste."
