AUSTRALIAN agricultural output will double over the next 40 years, with climate change predicted to increase, rather than hinder, the level of production.

A recent spate of reports forecasting the decline of Australian agriculture because of climate change have greatly exaggerated, and even completely misreported the threat of global warming, according to senior rural industry figures.

In a report published by the Australian Farm Institute, executive director Mick Keogh says agricultural output is projected to improve strongly through to 2050, with a growing global population and increased economic wealth boosting demand for Australian produce. If the sector adapts even modestly, production would increase rather than decrease as a result of climate change, the report says.

Predictions of a 20 per cent drop in farm production by mid-century were cited by Kevin Rudd and Agriculture Minister Tony Burke as justification for Australia's signing of the Kyoto Protocol.

In fact, Mr Keogh says, if global warming does occur, some areas such as southeast Queensland will receive more rain, and as a result will greatly benefit. Recent research has shown increased carbon dioxide in the atmosphere lifts plant production by up to 30 per cent in a phenomenon known as carbon fertilisation.

Mr Keogh, a well-respected industry figure, said much of the media reporting on the recent ABARE report Climate Change: Impacts On Australian Agriculture, was so misleading it risked eroding industry confidence in public research agencies.

"The reporting claimed that agriculture would be absolutely devastated, when that is not what the research showed at all," he said. "For a start the media consistently misreported the research results as a future reduction in agricultural output, rather than a slowing of future rates of growth in output."

He said the ABARE report chose a series of highly unlikely worst-case climate change scenarios and then projected them over a long period of time. ABARE also used the assumption that climate change would slow economic growth globally, thereby decreasing the demand for food. "With increasing world population this is highly unlikely," Mr Keogh said.

Also unlikely was the assumption that farmers would not adapt. "In many situations it appears as if an increase in temperature, certainly over the next few decades, will increase rather than decrease productivity," he said. "As well, open field studies are returning increases in plant productivity of about 15 per cent with increases in carbon dioxide in the atmosphere. Levels up to 30 per cent have been returned in laboratory studies."

Charles Burke, a fourth-generation cattle farmer at Lake Somerset, north of Brisbane, said most farmers were sceptical of the claims surrounding climate change and believed they were instead dealing with climate variability. After the recent dry, he hoped the Australian Farm Institute was right in its predictions southeast Queensland would benefit from more rainfall.

"No one has their head in their sand, but farmers want to move forward armed with the right information," he said. "The experts can't agree. Many farmers aren't convinced. We have to have the right information and the right tools. We need to make sure the information is correct."

Chief executive for the National Farmers Federation Ben Fargher said his members too had been concerned about the negative reporting of the industry's future. "We are very well placed to grow businesses into the future," he said.