From Chicago Tribune:
Terroir is a French concept. Terroir is "somewhere-ness," a combination of the macro- and micro-climate, soil, geology and culture. The French don't call a wine by the grape's name - 2 wines can be made of the same grape but be of different character because of their terroir.
Grapevines are creepers, with roots going through the topsoil and into the geology layers deep down, commonly 150 feet. A vintner can influence the topsoil but he cannot change the deep geology layers. This gives the wine a distinct character. The French do not allow irrigation, thus forcing the grapes to search deep for water.
There are 2 kinds of wine in the world: that of big growers and that of little growers. Big business works better for wine in places such as Argentina and Australia (where 3 companies dominate the wine industry). Most French wine still is made by thousands of small, independent vintners.
The French are not enthusiastic about the oaky taste of American wine. "I don't like oak shaping my wine", said one French vintner.
Because of global climate change and higher temperature, the grapes become sweet many days before the tannin level is ready (they used to "mature" at the same time). The average wine was 11% alcohol in the past; now it's 13% because of the higher sugar content.
Put a cork in intimidation over French wine. Rick Steves, Tribune Media, 02/2011.