Issue link: https://read.dmtmag.com/i/76198
CLIMATE CHANGE, or just freakish weather? That level of "As time goes on, we're becoming less comfortable about using history as a predictor." —Art DeGaetano change, Wolfe said, could allow growers there to produce Cabernet Sauvignon and Merlot, red grape varieties that haven't been adapted there. Unfortunately for Californi- ans, he added, warmer tem- peratures could push these red varieties out of the Napa Valley and into the arms of growers in Washington and Oregon, as well as encouraging growers in New York. In general, Wolfe said, Canadian farmers are not all unhappy about global warming, nor are farmers in Russia. The rate of warming could add horticulture at Cornell University and a founder of the Climate Change Center there. I Wolfe cochairs the Cor- Scientists believe bad weather years will become ever more frequent. by Richard Lehnert nell Soil Health Program Work Team and the Cornell Climate Change Program Work Team (which now includes 25 Cornell scien- tists). His outreach efforts include training for exten- sion staff, as well as direct outreach to farmers, policy- makers, and the general public on climate change mitigation. Highly unusual weather events, like those that dev- astated fruit crops across a large part of the Northeast and Great Lakes states this year, cause some growers to wonder what the future may hold for them. Others see it as just another freeze, some- thing that happened before and will happen again, every now and then. Climate change is real But beginning about 25 years ago, scientists realized that the climate was changing, and that it would be pru- dent for farmers to look at the risks—and possible oppor- tunities—that come with global warming, Wolfe said. "Climate preparedness makes good business sense," Cornell scientists say in a fact sheet on the Web site www.climatechange.cornell.edu. "The Earth's climate is always in flux, but today's pace of change is far beyond what previous generations of farmers have had to face. Climate change is already posing new challenges, such as increased risk of flooding, summer heat stress, and more intense pest and weed pressures." Since 1970, the average annual temperature in New York State has increased by about two degrees Fahrenheit, and the average winter temperature has increased almost five degrees. This change is enough to spur Cornell horti- culturist Dr. Alan Lakso and his colleagues to look at new opportunities for wine grape growers in the Finger Lakes area. www.goodfruit.com a 70-mile-wide band of better farming conditions all across the 16 time zones spanned by these countries by the end of this century. But most of the news about global warming is not t's time for fruit growers, and farmers in general, to start thinking about the effects climate change will have on them and their farms. "This is the first generation of farmers needing to think about this," said Dr. David Wolfe, a professor of good. "We do see an increased freeze risk in the future," said Dr. Art DeGaetano, a professor of earth and atmospheric sciences at Cornell and director of the National Oceanic and Atmospheric Administration's Northeast Regional Climate Center. The trend of climate change in the Northeast suggests that winters and springs like the one this year could be more frequent, he said. Warmer winters The winters have in fact been getting warmer, so trees can be pulled out of dormancy more easily in spring. "The paradox for fruit growers is that a warming climate can mean more spring frost damage," Wolfe said. As trees accumulate more growing degree days earlier, they leaf out and bloom earlier, subjecting them to a long period of vulnerability to spring freezes, and that period is not getting shorter. That happened this year. "Events like this year are not new," DeGaetano said. "But if in the past they happened once in 50 or 60 years, and in the future they happen one year in 10 or 20, this would be a greatly increased risk and would affect the kinds of decisions fruit growers make." Warmer winters, if it means higher minimum temper- atures, can be helpful when choosing varieties of grapes or peaches, which can be killed by extremely low winter temperatures. Most apples are very winter hardy, and low midwinter temperatures are not an issue if they remain completely dormant. Peaches and grapes, on the other hand, are less winter hardy. If climate change continues at its current pace, by the end of this century New York State will have summers like those in the Carolinas, the climate experts at Cornell say. Will New York be the peach state of the future instead of the second largest apple-producing state? Warming trends like these do not favor apples. A warmer atmosphere, with more water vapor, is already causing a clear trend across the United States for increased frequency of heavy storms and flooding—a trend projected to continue, Wolfe said. Warmer ocean temperatures provide more energy that can intensify hur- ricanes. Other extreme events, such as tornadoes and hailstorms, seem to be on the rise in some areas, but the jury is still out among scientists as to whether these types of extremes are due to climate change, he added. While most all climate scientists today believe that the climate worldwide is warming and its causes are man- made, scientists like Wolfe and DeGaetano are spending their efforts to help people adjust to the changes until Committed to Dedicated Service & Quality Trees For 74 Years & Counting Hickman: 19701 Lake Road Hickman, CA 95323 209-874-1821 21200 E. Dinuba Ave. Reedley, CA 93654 559-638-6675 Reedley: www.davewilson.com www.facebook.com/DaveWilsonNursery 800-654-5854 GOOD FRUIT GROWER AUGUST 2012 41 such time as public policy changes and the causes of global warming are addressed by nations, including ours. Years ago, climate scientists studied historical records as a predictor of the future, and obviously, farmers used that data. What states grow today is based on what the cli- mate dictates, DeGaetano said. "As time goes on, we're becoming less comfortable about using history as a pre- dictor. Historical data is still useful, but now we have to give more thought to what climate change will mean." Fruit farmers need to look at the emerging patterns when selecting varieties, making decisions about whether to install irrigation or whether wind machines will be needed for freeze protection. There are similar issues for pest control. There is no doubt that, as growing seasons get longer and warmer, growers will have to deal with higher disease pressure, more insect generations, and vigorous weed growth. Pests that are now south of New York will move north, and growers will have to learn to deal with new weeds, insects, and diseases. NOAA centers Cornell is one of six U.S. regional climate centers that NOAA operates. The others are located at the University of North Carolina at Chapel Hill, Louisiana State Univer- sity in Baton Rouge, the University of Nebraska in Lin- coln, the Illinois State Water Survey in Champaign, and the Desert Research Institute in Reno, Nevada. •