If you crave a pint (or two) at the end of a hard day, brace yourself: climate change is poised to make your favourite lager, ale or IPA more scarce and pricey.
On current trends, a crescendo of heatwaves and droughts will periodically cause sharp declines in barley yields, a crucial ingredient in most beer, according to a study published Monday.
"Decreases in the global supply of barley lead to proportionally larger decreases in barley used to make beer," said lead author Dabo Guan, a professor of climate change economics and the University of East Anglia in Britain.
Only the highest quality grain -- less than 20 percent -- is used to make beer, with most of the rest used as feedstock.
"High-quality barley is even more sensitive to extreme weather events linked to climate change," Guan told AFP.
During severe climate events, global beer consumption would decline by 16 percent, or nearly 30 billion litres -- equal to all the beer quaffed each year in the United States, Guan and an international team of researchers reported in the journal Nature Plants.
Beer prices in the wake of these disruptive weather events would, on average, double.
By volume, beer is by far the most popular alcoholic drink in the world, with nearly 200 billion litres produced in 2017.
Some countries will get hit harder by beer shortages and higher bar tabs than others, the study found.
In China -- whose 1.3 billion people collectively down more brew than any other nation -- consumption would fall by a staggering 4.3 billion litres in a bad year.
Britain would also get thirsty during a severe barley crunch, with consumption dropping by up to 1.3 billion litres, and the price of a pint doubling.
Per capita, most of the top-20 beer-drinking nations are in Europe, along with the United States, New Zealand and Australia.
- Keep calm, have a beer -
Guan and colleagues calculated the impact of severe weather events under different future climate scenarios -- ranging from a sharp reduction in greenhouse gas emissions to our current "business as usual" trajectory -- on yields in the world's 34 most important barley-growing regions.
An extreme weather year was defined as one with both heatwaves and drought -- in a barley region during growing season -- more severe than once-a-century events before global warming began.
From 2010 to the end of the century, they found, there will be 17 such events if humanity manages to cap global warming under two degrees Celsius (3.6 degrees Fahrenheit), and 139 if current rates of carbon pollution persist.
The next step was to estimate how these "barley supply shocks" would affect the production and price of beer in each region.
In a climate-addled world where staple crops such as wheat, corn, soybeans and rice are predicted to decline in yield and nutritional value, pressure will likely mount to use barley as a source of food rather than to make brew.
"Climate change may undermine the availability, stability and access to 'luxury' goods," said Guan.
At the same time, the "cross-cultural appreciation of beer" is deep and widespread, he noted.
"There is little doubt that for millions of people around the world, the climate impact on beer availability and price will add insult to injury," he said.
As the adage goes, "It's all fun and games until the beer runs out."
The top exporters of barley are Australia, France, Russia, Ukraine and Argentina, with many European countries filling out the top-20.
The biggest importers are China, Saudi Arabia and Iran, with three top brewing nations -- Netherlands, Belgium and Japan -- just behind.
© 2018 AFP