Wednesday, October 15, 2014

Farmers unwittingly adjust to climate changes

The Ohio wine industry has been getting more and more dependent on French grapes over the last 30 years. The vinifera, or French grape, the species of grape known to produce the world's best and snootiest wines, is very tender, which would make sense since it is adapted to a Mediterranean climate. But for the last few decades Ohio winemakers, and those in many other temperate regions, have been planting more and more vinifera to replace the good old American grape varieties they used to grow. American grapes, like Concord, the grape juice grape, and French-American hybrids are much hardier in the normal Midwestern winters—or what used to be known as normal winter. But American grapes are better known for producing juice or sweet wines, while hybrids have never been able to compete with the old French standbys in wine quality in the eyes of the Wine Spectator crowd.
An Ohio vineyard testing the limits
Regions like the West Coast have climates much like that of France, and it's in places like this where vinifera thrives. But before climate change began to bring milder winters (devasting floods and hurricanes) to the rest of the country, wineries were forced to look to American grapes, and to breeders to develop cold hardy French-American hydrids, in order to have productive vineyards to base a business on. Vinifera vines could not survive most Midwestern winters without a down coat, only questionably able to survive as low as -10 degrees F at their hardiest.

But as the climate has changed over the last few decades, the tender vinifera has crept into the locally-made wine market in the Midwest. It started out as a sort of testing of the waters, with a few renegades planting small vineyards and finding the grapes could survive most winters in the new era of 400 ppm. After a few were successful, they attracted the attention of others who saw dollar signs. Ohio wineries realized that their hardy native grapes didn't produce the kind of wine that demanded top dollar, and didn't produce what is the socially-accepted definition of good wine. So they scrapped their American vines and replaced them with the much more valuable (and vulnerable) French vines. It's unlikely that any of them suspected they were only able to grow the vines now because the climate was changing and the world was gradually warming.

All primary buds on these vinifera were killed. Secondary and tertiary buds sprouted. Many vines died back to the ground.
Then last winter, Ohio winegrowers were surprised by a sudden change in their mild winters. The warming arctic had pushed the polar vortex from its normal position atop the globe. Huge acreages of the state's vinifera vines were wiped out by the frigid winter. Those that did survive died back to the ground, saved only by a thick cover of snow that insulated their roots against the far below zero temps.

Of course, the key to understanding climate change is to realize that though it is a gradual warming on a global scale, there is what's known as climate chaos on a local scale. On a local scale climates have become more erratic, bouncing back and forth between extremes in no predictable manner. Most places I've been to, the locals seem to know that things have changed in the last few decades. After last winter, while relative newcomers in this part of Missouri talked with surprise about the cold winter, the locals claimed it was a "normal winter", like the ones they had when they were younger— like 40 years ago. Of course, none of the locals seemed to have an opinion about why “normal” hadn't happened in 40 years--but it sure wasn't climate change.

Early warm weather, then a late hard frost killed new shoots (in brown).  Secondary shoots (in green) are weaker and less fruitful.

Planting grape vines is no small investment in time and money. Grapes take at least 4 years to produce a crop big enough for winemaking, and that's in ideal conditions. Replanting vinifera might seem foolhardy, but it's likely that the mild temperatures brought about in most winters by climate change will lure wineries in temperate regions to invest again.

Some permaculture advocates like Mark Shepard think perennials are the key to dealing with climate change, but this seems like faulty logic. Perennials can take longer than a decade to become fruitful and at any time the entire plant can be wiped out by weather extremes. As the climate gradually changes, perennials become less suited to their environment. If you plant a perennial fruit tree, by the time it comes into production, the climate may no longer be suitable for it. On the other hand, in a bad year an entire annual crop might die, but if you plant a diversity of annuals, it's likely something will do well in any season. Even if one season is bad, it's possible to try again the next year and be successful. If you notice a trend in the weather toward warmer climates, you can plant varieties that do better in warmer weather and get a crop the same year. With perennials, you may plan for a warmer future by planting less hardy varieties, but it only takes one hard winter to wipe out years of investment, and you'll have to wait years more before you see fruit again.
Disease like this bunch rot will likely increase with climate change
I think it's likely that Midwest wineries growing vinifera will continue to see their investment brought into question. Aside from being vulnerable to temperature extremes, vinifera is very susceptible to disease, being adapted to a dry Mediterranean climate, which could prove to be another costly problem as climate changes and as fossil fuel supplies dwindle. Vineyards growing vinifera are already investing a lot in a disease spray regimen just to be able to get a crop. Without heavy application of modern chemical pesticides (which owe their existence to either direct conversion from fossil fuels like natural gas or to fossil fuel intensive production processes), it would be impossible to grow vinifera outside Mediterranean climates. Who knows what will happen as the climate changes more. This season in Missouri, the wet weather contributed to an increase in disease, and unusual late season heavy rain just before harvest led to fruit cracking, which can destroy an entire crop (and did for me this season).
There are other obvious changes in the practices of farmers around the country in response to climate change. The increased appearance of irrigation systems in soybean and corn fields in the Midwest and Central plains isn't just because irrigation increases yields, it's because without it there would be no crop. And currently vast acreages of walnut, pecan, and other crops are being uprooted after dying from lack of access to water in California's continuing drought. All of California agriculture is vitally dependent on irrigation from unreliable water sources that will only become less reliable as the climate changes. This drought and the resulting crop losses may be the first signs of its decline. This American Life did a segment about the impact of drought on farmers in Colorado and the continued denial of the existence of climate change by politicians and the farmers themselves.
One way to easily quantify the impact of climate chaos on farmers is to look at the increase in crop insurance payments that has occurred over the last decade or so. When a conventional farmer's crops fail, they collect insurance. When they collect insurance payments, American taxpayers foot the bill. Because farmer's crop insurance losses are paid for with federal taxes, the 2012 drought alone cost each American $51.
Whether it's grapes, pecans, or wheat, climate change is going to make agriculture much more uncertain in coming years.  Should we be worried about it? Well, it is only our food supply.  Probably somewhere food will be grown despite climate chaos, and the rich will be able to afford it.  But likely there will be a lot less of it to go around before too long, and eventually the reality will hit us even here in our American walled fortress.

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