GENEVA - The 42nd World Congress of Vine and Wine began on Monday, with some 500 experts worldwide discussing sustainability in wine production and consumption.

The theme of the conference, hosted by the International Organization of Vine and Wine (OIV), is: "Preservation and innovation: expectations at the environmental, economic and social level."

Speakers come from countries traditionally associated with vineyards such as France, Spain, and Italy but also from China, Japan and Bolivia and consumer countries such as Denmark and Britain, said the OIV.

"Spain remains the leading country for area cultivated with 969 kha (kilo-hectares), ahead of China (875 kha) and France (793 kha)," said OIV Director General Pau Roca while presenting his report.

"The Chinese wine growing area continued to increase by 10 kha between 2017 and 2018," he said, noting that Chinese are also consuming more wine.

Roca also noted that China, despite an 11 percent drop in production in 2018, is the world's leading grape producer at 11.7 million tons (mt) -- 15 percent of global grape production, followed by Italy (8.6 mt), the United States (6.9 mt), Spain (6.9 mt) and France (5.5 mt).

With 33 million-hectoliters (mhl), the United States has been the biggest consumer of wine in the world since 2011, followed by France (26.8 mhl), Italy (22.4 mhl), Germany (20 mhl) and China (17.9 mhl).

The congress will also address climate change, to which vineyards are very sensitive, as well as the development of products and how to protect vines, said the OIV.

The OIV is an intergovernmental organization of a scientific and technical nature of recognized competence for its works concerning vines, wine, wine-based beverages, table grapes, raisins, and other vine-based products.

As of Nov 6, 2018, the OIV was made up of 47 member states, it says on its website.