(CNBC) - The wine grape has been called "the canary in the coal mine of agriculture." There's no question it has gotten far warmer in many of the world's wine regions. In fact, it has become too hot to make truly elegant Chardonnays in some previously celebrated regions like Napa.

Today, the canary has flown 800 miles north all the way into Canada, to what some scientists call the "magical climate zone" for Chardonnay, and that's exactly why I moved there.

Australian by birth, I was a practicing lawyer before turning my sights to winemaking in 2002, when I began my career in the challenging heat extremes of the Hunter Valley in Australia, located 32 degrees latitude south of the equator. Australia's oldest wine region, Hunter Valley temperatures can exceed 113F (45C) and climate change has been a major issue there since the beginning of the 21st century. During my tenure, our harvests typically began in mid-January, with some years as early as the first week in January. Looking back 30 years ago, the harvest used to start in early-February, a dramatic shift due in part to the effects of climate change.

To make amazing wines, I knew I had to move to a cooler region, so in 2007, I relocated to 38 degrees north of the equator to the Russian River Valley, Sonoma County. Here I experienced first-hand the challenges California is facing with drought and dwindling water supplies. Since 1931, temperatures on the northern coast have been increasing by approximately 0.03 degrees Fahrenheit every year. Additionally, the number of growing degree days over 95F (35C) have increased by up to 10 days annually in Northern California. The major issue facing some of these regions is that they are moving into the upper limits in terms of optimal temperatures to produce premium quality wines.