WELLINGTON, New Zealand — The price of beer is likely to rise in coming decades because climate change will hamper the production of a key grain needed for the brew -- especially in Australia, a scientist warned Tuesday.

Jim Salinger, a climate scientist at New Zealand's National Institute of Water and Atmospheric Research, said climate change likely will cause a decline in the production of malting barley in parts of New Zealand and Australia. Malting barley is a key ingredient of beer.

"It will mean either there will be pubs without beer or the cost of beer will go up," Salinger told the Institute of Brewing and Distilling convention.

Similar effects could be expected worldwide, but Salinger spoke only of the effects on Australia and New Zealand. He said climate change could cause a drop in beer production within 30 years, especially in parts of Australia, as dry areas become drier and water shortages worsen.

Barley growing parts of Western Australia, South Australia, Victoria and New South Wales would likely be harder hit than growing areas in New Zealand's South Island.

"It will provide a lot of challenges for the brewing industry," even forcing breweries to look at new varieties of malt barley as a direct result of climate change, Salinger said.

New Zealand and Australian brewer Lion Nathan's corporate affairs director Liz Read said climate change already was forcing up the price of malted barley, sugar, aluminium and sugar.

Read said that in addition to climate change, barley growers are grappling with competition from other forms or land use, such as the dairy industry.