Brian Walsh, director of winemaking at Yalumba, has told business leaders in Adelaide that a rise in temperatures could prevent the growth of some cooler grape varieties, such as shiraz and riesling, for which South Australia’s Barossa Valley is famous. ”Basically, the Barossa will disappear,” he said.

A similar observation has been made by viticulturist, Frank van de Loo, at the Mt Majura vineyard near Canberra. 

Mr van de Loo has recorded grape harvest days each year. "Over the last 20 vintages, this is our 21st vintage, we’ve been coming in at an average of 2.4 days earlier each year," he says. "Of course the curve bounces around a lot from year to year depending on the individual season, but it has a very clear trend. Before long, we’ll have to quit growing chardonnays."

Mr Walsh pointed out that regions in Italy and France grow wine in hot arid conditions similar to Australia, and peolple there choose wine from a particular region. But Australians choose wine based on the grape varieties, like shiraz, reisling or chardonnay and in the future it may not be possible to grow these varieties in regions like the Barossa.

He said that winemakers need to start looking at varieties for hot, dry climates now and not wait 30 years and say ”I wish I’d done something”.

”It’s a risk strategy and out of some of those times we might just stumble across something which is a fantastic idea we haven’t thought of yet," he said.

A Canadian farmer, Gary Lewis, has developed a system that pipes tractor exhaust emissions through a condenser and into the pneumatic system of air seeders, which then injects the carbon and nitrogen-rich emissions into the ground along with the seed. The exhaust gases stimulate microbial activity and root growth, allowing the plants to more efficiently extract nutrient and moisture from the soil.

Mr Lewis says that tractor exhaust has allowed him and other farmers working with his technology to grow excellent crops without using conventional fertilisers. He says that he has not used fertiliser on his 250-hectare irrigation farm for at least six years, yet he had seen no loss of production, his soils had moved from pH 8.0 (the same as his irrigation water) to a pH of about 7.0 and soil organic matter levels are now at about 10 per cent.

In addition to the savings in fertilizer, he sees potential income from carbon offsets through the process.

About 150 farmers around the world, including in Australia, Britain, South Africa and recently China, are trialling the technique.

Ian Linklater, who grows wheat on a 3,845 hectare property near the Murray River north of Mildura, was the first Australian farmer to test the system. He spent $20,000 customising equipment that cools his tractor’s exhaust fumes and injects them into the soil as he sows his crop. He says that he has saved around $500,000 in nitrogen and phosphorus fertilizers in the two years that he has been using the system.