Some grapes like it hot.
But for growers of Pinot Noir, mild summers tempered by chilly nights and fresh ocean air make for award-winning, fortune-finding wines. Such a climate has turned Oregon into a producer of some of the world's most highly regarded Pinot Noir. This variety, which seemed to receive a strong sales boost from the 2004 film Sideways, accounts for about 60 percent of Oregon's wine production and 70 percent of Oregon's total wine sales.
But as global warming nudges average temperatures upward across the planet and causes tumultuous, grape-damaging weather changes, winemakers in Oregon are wondering just how their superstar grape will fare — if at all.
"Fifty years from now, we could be required to change to new grape varieties," said Harry Nedry-Peterson, owner of Chehalem Wines in Newburg.
Already, Nedry-Peterson says, the wines of Oregon are changing. He says the average alcohol content in his wines has increased over the past 20 years — a result of higher sugar levels produced in warmer, sunnier years. And while some of his best vineyards were "only marginally adequate" producers 30 years ago, today they produce first-rate wines, he says.
"The warming we've seen has benefited those vines," Nedry-Peterson said.
But if the warming trend continues, then what? Nedry-Peterson says moving vineyards to higher elevations could keep the good Pinot flowing from Oregon's wine country. Shifting to north-facing hillsides could buy some time, too — and a few degrees — as could allowing greater foliage growth on each vine to shield the grapes from the sun.
Another area winemaker, Alex Sokol Blosser, of his family's namesake winery in the Dundee Hills, says that irrigating Oregon's mostly dry-farmed vineyards could mitigate somewhat for increasingly warm summers.
Warmer summers are already a reality. Greg Jones, a research climatologist at Southern Oregon University, says the last decade was, worldwide, the warmest ever recorded, and that Northern Hemisphere temperatures are now between one and three degrees Celsius warmer than the 1961 to 1990 average.
Though Jones says small adjustments in basic vineyard management will probably allow Oregon's winemakers to deal adequately with gradual long-term temperature changes, what could really hurt grape growers, he says, are the extremes, like record-high temperatures, unprecedented storm events, cold spells like farmers have never seen before, and severe droughts. (As we've reported, the extreme weather changes expected will also make for extreme food price fluctuations throughout the world.)
Just last year was considered the most turbulent weather year on record in Oregon, says Jones. That spring was the coldest since 1890, he says, that June, the wettest, that September the warmest, and that fall the driest.
"Pinot Noir is still king here, but these events make us wonder, 'What are the drought and heat thresholds that different grape varieties can stand?" Jones says.
Pinot Noir is a notoriously difficult grape to grow. It has tight, almost seamless clusters that may trap moisture and begin rotting should any late-season rain fall on them. The grapes are also particularly susceptible to sunburn, which damages the complex nuances of flavor and aroma that can make Pinot Noir such a fine and expensive wine. Thus, in a warmer or wetter future, other, hardier grape varieties could be in order.
Ray Nuclo, vineyard manager at Croft Vineyards in the Willamette Valley, believes a warmer future would provide plenty of wiggle room in Oregon. That is, while Pinot Noir quality could falter, winemakers could still turn to Syrah, Merlot, or Cabernet Sauvignon as possible replacements. California's winemakers are struggling with similar uncertainties.
"The Pacific Northwest is a cool area already, and if that's the scenario, we could be pushed out of growing Pinot Noir," Nuclo says. "There wouldn't be a lot of good options for us. We're already a cold area at about the limit of where Pinot Noir will grow, and if it got much cooler I'm not sure what we could do."