One of France's biggest export industries is facing a devastating blow after an unusually severe frost earlier this month damaged vineyards across the country, heaping pain on winemakers already reeling from the pandemic and US tariffs. The frost has affected 80% of vineyards in France's primary wine growing areas, according to the European Committee of Wine Companies. "This is expected to cause a yield loss ranging from 25% to up to 50% in some regions," the trade body told CNN Business on Wednesday. The destruction spread across the Rhone Valley, Bordeaux, Burgundy, Champagne, Provence and the Loire Valley, said Anne Colombo, president of the Cornas appellation, a wine-growing area in the Rhone region.