Climate change threatens the world with drought, rising sea levels, powerful storms - and a global beer "crisis", say researchers.

The effects of global warming are likely to lead to sharp falls in crop yields of barley, an essential beer ingredient, scientists are predicting.

Droughts and heat waves were expected to cause barley declines of up to 17% in parts of the US, Europe, Australia and Asia where the grain is grown most.

As a result, the cost of beer could soar. According to the US scientists' economic model, the price of a six-pack of beer could go up by an extra €17 in Ireland.

Research co-author Dr Steven Davis, from the University of California at Irvine, US, said: "The world is facing many life-threatening impacts of climate change, so people having to spend a bit more to drink beer may seem trivial by comparison.

"But there is definitely a cross-cultural appeal to beer, and not having a cool pint at the end of an increasingly common hot day just adds insult to injury."

Only 17% of the barley produced in the world is used in brewing, the authors point out. Most is harvested as feed for livestock.

The researchers predicted that hungry animals would be first in the queue for available barley - ahead of thirsty humans.

Barley growing regions including the northern Great Plains of the US, the Canadian prairies, Europe, Australia, and the Asian steppe were all likely to experience more frequent droughts in years to come as a result of global warming, the study in the journal Nature Plants reported.

Beer prices were predicted to rise most in wealthy beer-loving countries such as Belgium, Canada, Denmark and Poland.

Co-author Dr Nathan Mueller, also from the University of California at Irvine, said: "Current levels of fossil fuel consumption and CO2 (carbon dioxide) pollution - business as usual - will result in this worst-case scenario, with more weather extremes negatively impacting the world's beer basket.

"Our study showed that even modest warming will lead to increases in drought and excessive heat events in barley-growing areas," added Dr Mueller.