Regional effects of global warming vary in nature. Some are the result of a generalised global change, such as rising temperature, resulting in local effects, such as melting ice. In other cases, a change may be related to a change in a particular ocean current or weather system.
In general, white wines exhibit more acidity than red wines. Acidity gives wine its crispness on the palate. A dry wine needs good levels of acid to provide liveliness and balance; sweet wine needs acidity so it does not seem cloying. Too much acidity will make the wine seem harsh or bitter; too little and the wine will seem flabby and dull.
Note: Sweet (unfortified) wine is usually lower in alcohol than dry wine. To be considered sweet (doux or dulce), a sparkling wine must have more than 50 grams/liter residual sugar (i.e. sugar not used in fermentation, thus lower alcohol level) or 7.5 grams per 5 oz. glass. Slightly sweet (Demi-Sec, Semi-seco) is 32-50 grams/liter.