Over the past decade, Mr Brimblecombe has observed that rainfall on his Gatton, Qld, farm is becoming more sporadic, with heavier falls spaced further apart; and that it has become hotter.

He used to plant beetroot in late January/early February; planting times have now moved ahead a full month.

Both changes are in line with climate change forecasts.

"Call it climate change, call it what you like—it's impacting on our business," Mr Brimblecombe said.

But the proposed solution to climate change promises to be damaging, too.

When the Queensland Department of Primary Industries profiled his emissions, Mr Brimblecombe discovered his operation emitted about 850 tonnes of CO2-e a year.

That promises a hefty emissions payment, but it is the upstream costs of fertiliser, fuel and electricity, due to hit with the introduction of the CPRS in 2011, that have Mr Brimblecombe worried.

ABARE has conservatively estimated that the horticultural sector will experience a 1-3 per cent rise in costs under the CPRS; some farm organisations have proposed that the cost increase will be closer to 5-7 per cent.

"Not many farms make that sort of profit," Mr Brimblecombe said.

"We have to ask some questions about what this tax is actually doing.

"Are we interested in food production, or do we want to import our food? Because I’m not confident that the rest of the world is rushing to follow our government's lead.

"That becomes an issue of food security.

"The only option I can see at the moment is that food is excluded from the scheme, as it is with the GST."