How climate change is affecting our food

The effect may not yet be obvious in grocery stores and markets, but behind the organic apples and bags of rice and cans of cherry pie filling are hundreds of thousands of farmers, plant breeders and others in agriculture who are scrambling to keep up with climate change.

Drop a pin anywhere on a U.S. map and you'll find disruption in the fields. Warmer temperatures are extending growing seasons in some areas and sending a host of new pests into others. Some fields are parched with drought, others so flooded that they swallow tractors. Decadeslong patterns of frost, heat and rain — never entirely predictable but once reliable enough — have broken down. "Farming is no different than gambling," said Sarah Frey, whose farms in the South and the Midwest grows much of the nation's watermelons and pumpkins. "You have all of these consequences that farmers weren't expecting."

Indeed, a two- or three-week shift in a growing season can upset supply chains, labor schedules and even the routes that honeybees travel to pollinate fields. Higher temperatures and altered growing seasons are making new crops possible in places where they weren't before, but that same heat is also hurting traditional crops. Here are a handful of everyday foods that are facing big changes:

Most organic apples in the U.S. come from Washington state, which grows about 230,000 tons a year. Hotter spring weather can increase diseases like fire blight. And hotter temperatures can subject both organic and conventionally grown apples to sunburn, which causes defects on the fruit's skin. Some growers have taken to installing large nets over orchards to reduce the intensity of the sunlight, but the process is expensive. Unlike many row crops, which can be replanted year to year, orchards can take a decade or two to regrow.

Growers rely on a long, cold winter and a slow, cool spring so trees won't bud and bloom before the threat of a final freeze is over. But lately, Grand Traverse Bay hasn't been freezing over reliably, so warmer temperatures arrive too soon. There have been two total crop failures in a decade; the last one before that was in 1945. Spring weather has become more violent. The spotted wing Drosophila, an invasive fruit fly, also showed up in 2010, and many farmers believe it is spreading quickly as a result of shifting climate patterns.

The fruit fly that is vexing cherry growers in Michigan is also attacking the raspberry crop in New York. Winters haven't been as long or as cold, so the flies are appearing earlier; organic fruit are especially at risk because of limits in the use of pesticides. Couple that with mild winters that don't kill off pests, and unusual weather patterns that don't bring rain when they should — or bring so much that farmers can't get into the fields to work or have to battle fungus — and organic berries aren't such a good bet anymore.

An earlier growing season has, in many ways, been good for farmers like Sarah Frey. She used to start harvesting Florida watermelons in mid-April. This year, her crews were picking in March. She'll be picking earlier in Georgia and Missouri. But earlier and longer growing seasons have consequences. For Frey, harvesting watermelons earlier puts her into competition with the late-winter crop from Mexico. And more restrictive immigration policies could mean she won't have enough workers when she needs them.

The wild blueberry has long been an essential player in Maine, but unpredictable weather is challenging the 44,000 acres where the commercial low-bush berries grow. The season has stretched out four weeks longer, summers are becoming warmer and frosts are becoming erratic. Drought isn't helping. Many smaller growers, some tending fields that are 100 years old, don't irrigate, but that expensive step may become necessary. And the same fruit fly troubling cherry and raspberry growers is also a concern in Maine.

Gene Mealhow's family lost its farmland in the 1980s. Now he grows pearly flint popcorn, whose genetics he can trace to the 1840s, on about 300 acres. When he was growing up, predictable spring rains led to even summer heat and a reliable crop of corn. Not anymore, he said. This season, some of Iowa's big corn producers had to leave crops in the rain-soaked fields. Mealhow is doing what many small farmers are: diversifying. He'll work through his inventory of popcorn, then grow onions, sweet corn and tomatoes.

The symbol of Georgia and the mainstay of a Southern kitchen, peaches could be devastated by climate change. They need a certain amount of consistent cold weather — what growers call chill hours — followed by dependably warm weather. Without enough chill hours, peach buds are weak, and weak buds make poor fruit. In addition, trees are blooming too early and then being hit by unusual frosts, which result in less sellable fruit. In 2017, a warm winter destroyed almost 85% of the state's $30 million peach crop.