Illustration: Aïda Amer/Axios Illustration of a beer tap dripping droplets of beer. The U.S. is experiencing a shortage of carbon dioxide and Boston beermakers are beginning to worry they won't have enough of the gas to get their products to market. Driving the news: A CO2 production hub in Jackson, Mississippi, became contaminated by an extinct volcano, which cut down on an already limited supply of the gas. The pandemic put pressure on the CO2 market and drove up prices in part due to the immense amount of dry ice (frozen carbon dioxide) needed to transport COVID-19 vaccines last...