Global warming is something farmers prefer to call climate change and see it generally as a year to year issue. But a lot of them are skeptical about it.
“It's happening in the world but fortunately not in the Midwest yet,” says grape grower Jerry Gulke.
Whether they think it's real, many don't want to wait around to find out.
“We run the rows east and west so the sun never shines directly on the clusters and burns them,” says grape grower Jim Verhey of Silverado Wine Growers.
Some of the biggest concern about climate change is in California’s wine country. In the Napa valley, temperature swings from day to night help make world class wine, but a study published by the national academy of sciences predicts wine production here could disappear by the end of this century as Napa gets too hot.
But Verhey hasn't completely drunk the cabernet Kool-Aid on that one.
“It may move the temp up a degree or two, but it will not impact that 30-40 degree temperature swing which is so critical for the quality of grapes that we generate here.”
At the same time he's preparing for more heat.
“We've actually put some spacers across the top to allow the canopy to hang out over the grapes,” says Verhey.
After all, vineyards are built to last decades. Each variety works in a specific region as ripping out and starting over is expensive.
“If it gets too warm all bets are off,” says David Graves of Saintsbury Winery. “We may have to change what we do. It may mean changing the grapes we grow or moving where we grow them,” says Graves.
Most of the viable grape growing regions are being pushed toward the coast.
Climatologist Greg Jones says modeling shows global warming not just impacting wine country, but everything from orchards in Washington to corn farms in the Midwest. Technology can help reduce the dependence on water, but what about the heat?
“I think we've established that corn can live without some water but it does not like the heat,” says Jerry Gulke, another grape grower in the region.
“We can ill afford to be blindsided by a disastrous crop and we are looking ahead to try and prevent that if it happens,” adds Gulke.
Many climatologists dispute the dire global warming models saying they've failed in the past.
“We could be wrong,” says Prof. Jones.
Meantime farmers hedge their bets, even as many people don't feel compelled to act on something that may or may not happen in 50 years.
“It's kinda like telling somebody the gas tank's full and yet you keep driving and you say well it's getting toward empty, said Jones. "Until it's right at empty people don't stop!"