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The Weather Man

At the 19th Annual Energy Conference, Iowa State University climatologist Elwynn Taylor shared his near-term forecast, along with his broader views on greenhouse gases, global warming and the very real possibility of a future chock-full of erratic weather.
By Tom Bryan | July 20, 2007
Elwynn Taylor is all about weather and probabilities.

So it's ironic and fitting that on a hot mid-May morning he's at a conference inside an excessively air-conditioned casino—a place where chance is everything and the temperature is always the same—speaking about the risks of global warming.

"A lot of things we climatologists work with have a chance of occurring," he says, sauntering into his breakfast presentation at the 19th Annual Energy Conference put on by Minneapolis-based U.S. Energy Services. This event is at Mystic Lake Casino in Prior Lake, Minn., and includes presentations from the usuals: energy experts, risk management professionals and the like. But Taylor, who sounds like Paul Harvey and has retained the genuineness of a Midwest farmer's son, always steals the show with his 7 a.m. weather presentation. The title of this year's speech—which is really more of a neighborly chat than a speech—is narrowly titled "A Shift in Weather Trends," a topic he'll come around to in 20 or 30 minutes.

Taylor talks for an hour and conference attendees are well into their second cup of coffee by the time the Iowa State University climatologist serves up his summer weather predictions. He says pre-season moisture is good across the Corn Belt, but there's a looming 19-year drought cycle that could—yet probably won't—hit the Midwest this year. The effects of that ever-perplexing El Niño/La Niña thing is maybe a wash and semi-permanent pressure patterns are positive while jet-stream-controlling weather in the Gulf of Alaska remains suspicious. "Growing degree days" are working in our favor, though, and if the sun doesn't shine too hot on corn country late in the summer we could have bumper yields like we saw in 1994. That will happen only if the weather is warm early on and cools off later in the prime growing season. If it starts out warm and stays warm—or gets hot like it did in 1988—trouble could be on the way. He pauses before predicting that corn yield averages will land in the ballpark of 154 bushels per acre nationwide, with a greater than normal chance of record-high yields and corn prices settling out at roughly $2.45 a bushel. But that's just one scenario, he says.

Like a surgeon, though, a climatologist delivers the good news first. With a stern face, Taylor says the weather this summer isn't likely to be mellow, run-of-the-mill sort of stuff. The professor's stats—and his graduate students—tell him the standard deviation is pretty big this year, which means the weather in the Corn Belt should be very good or … well, pretty bad. "In other words, there's a good chance of having a great year and a good chance of drought," Taylor says. "That gives us a lower chance of being average."

Erratic weather, we soon learn, is what Taylor is most concerned with. He is by no means a global warming alarmist, but he understands that during warming cycles—and we're almost definitely in one—the swings of erratic weather are more viscous and unpredictable than at other times. "The more erratic the weather becomes, the more it hurts us," Taylor says. "And the first person to pay the cost is the Midwest farmer. They're paying the greatest toll from erratic weather associated with global warming."

Natural Cycles?
In the early '90s, Taylor gave a presentation at the annual meeting of the American Meteorological Society. The gist of his speech hinged on one central question: Is erratic weather the primary manifestation of global warming? "About 15 people came to hear me—and eight of them were my students," Taylor quips, before turning suddenly serious. "This year at the national meetings there were 31 papers on that subject—5,000 people listening to them," he says. "The world pretty much knows now that global warming isn't just about warmer temperatures. It's about the weather becoming more erratic. That is, in fact, its primary manifestation."

While Taylor believes entirely in global warming, he hasn't yet jumped on the popular "Inconvenient Truth" bandwagon. "I don't know how much people have caused," he says. "Nobody really knows … but what I do know is that we had a global cooling period from around the middle 1800s to around 1900, global warming from 1900 to around 1940, global cooling again from 1940 to 1972, and global warming since 1972. Thermometers have measured this for us."

The professor pulls up a slide picturing the north edge of Alaska in 1979. Then he quickly displays another picture of the same area in 2003, showing how far back the sea ice receded in 24 years. "Twenty-five percent less ice around the North Pole in 2003 compared to 1979," he says.

Building on his point, Taylor jumps back five decades—which he does with ease—to 1958, the year the nuclear submarine USS Nautilus dove beneath the ice of the North Pole. "It was world news," he says, explaining that it was the first time a submarine crew was able to measure the thickness of the polar ice cap. Such measurements are now conducted annually, and each year the numbers look grimmer. About one-third of the thickness of the ice is gone, as is 25 percent of its coverage. "Fifty years and half the polar ice sheet is gone," Taylor generalizes. "If it continues to melt at this rate you'll be able to sign up for a cruise to the North Pole in late summer 35 years from now."

So why, with such strong evidence of global warming, is Taylor reluctant to blame human activity—specifically, increased emissions of greenhouse gases like carbon dioxide—for its apparent acceleration? Because the bigger picture tells him there are more powerful cycles at play. He justifies his pragmatic position with convincing anecdotal evidence from the story he tells about Greenland's super-thick ice cap starting to melt back and revealing that humans inhabited the place 1,400 years ago. "You could have taken your ship across the North Pole late in the summer then, too," he says. "So what we've discovered is there have been occasions throughout history when sea ice in the North Pole would go away during certain times of the year and other spans of history where the ice was essentially permanent. These things go back and forth. We wonder now if there was ever a time when there was no glacier on top of Greenland at all. Geologists say yes—a short 3 million years ago we didn't have any permanent year-round ice on the planet. These things come and go in natural cycles."

Learning from the Ozone Example
So, like most respected scientists, Taylor accepts that global warming is occurring. But he says the extent to which man is contributing to its acceleration is debatable. That said, Taylor has obvious concerns about the probable effects of greenhouse gases contributing to the warming of the Earth's atmosphere, and hence triggering increasingly erratic weather. Climatologists are by necessity historians. They look to the past to see the future. But without any recorded history of how greenhouse gases effect global warming and weather patterns on Earth, Taylor says the best he can do is look to other examples of manmade emissions that have caused atmospheric blunders. The hole in the ozone layer is a perfect example.

Just as the acid rain scare of the '70s and '80s gave way to fears about the hole in the ozone layer in the '90s, it too has been replaced with global warming concerns. That's probably OK, Taylor says, because the hole in the ozone layer has basically stopped growing. The growth of the hole has been curtailed because—and this is a vastly underrated example of global cooperation—human beings have stopped using the Freon gas that eats away at the protective atmospheric stratum. "It's still a concern," Taylor says, "but we believe we have it under control now—it's not getting worse."

According to Taylor, who has a remarkable story to share about his personal involvement in one of the earliest discoveries of Freon's affect on the ozone layer, the fact that the infamous hole is not getting larger is exceptionally important. Living in the sun's unfiltered rays beneath the ozone hole in the early '90s proved fatal for humans and animals alike. In 1992, the ozone hole sat over the tip of South America, a populated area near Santiago, Chile, and human skin cancer rates there almost tripled as a result. That year, tens of thousands of yearling sheep and llamas died of eye cancer. Taylor says what happened in South America in 1992 was an example of what might have happened globally if people around the world had not acted. "It's no longer going to be a great calamity for the Earth as it was clearly headed for before we put the controls into effect," he says. "So we've corrected a major climate change that people were causing. … The half life of Freon is about 90 years, so in about 180 years it will be virtually gone or have a negligible affect. Until then, we'll just watch it and tell people to keep their sheep out of the ozone hole."

The point that Taylor makes with his ozone story is not, "Hey people, the ozone hole is our fault, so global warming probably is, too," but rather, "Hey people, human beings have cooperated and stopped the ozone hole from getting worse, so we just might be able to stop global warming from getting worse, too."

While the world continues to debate the causes of global warming, Taylor is more interested in what warmer weather is causing. He and other climatologists want to better understand how warmer temperatures affect weather, nature and related human activities such as agriculture. He says history has established that warmer global temperatures affect nature. He talks about what happened in 1847—"the worst year of that century"—which marked the peak of a major global warming cycle. "It was the coldest, wettest winter of the 1800s, and the hottest, driest summer," he says, explaining that subsequent drought years were less severe, at least until the worst drought of the next century hit in 1936. A couple of decades later there were droughts in 1954 and 1956, but those dry periods weren't as severe as their predecessors because a cooling period kept conditions relatively benign.

Taylor says the Midwest is due for another drought soon, and since serious droughts occur every 19 years on average, the worst one of the century should hit around 2025.
Winter weather is also predictably cyclical. Taylor explains that the North Atlantic Oscillation Index (NAO) is based on ocean water temperatures between Maine and Greenland that cause cycles of harsh and mild winter weather in the United States. "The NAO won't tell you what any given year is going to be, but it will tell you the trend," he says, pointing out that the next 20 years or so may be warmer than usual. Overall, though, the winter weather will probably be more volatile and hard to predict. The year-to-year volatility of heating demand in the United States has increased since the mid-1970s, and is likely to keep increasing as the current global warming trend continues. Taylor says there is strong evidence that a winter cooling cycle occurred from 1950 to 1971 and that a warming cycle has been in play since then. This natural warming cycle, which should last about 89 years, is expected to peak around 2025—maybe after that big drought Taylor prophesizes. The professor pulls up a slide showing that "heating day requirements" have gone down since 1980. "Global warming started affecting our winters," he says. "The winters have been warmer all through the Midwest. This has been shown as evidence that, yes, we have global warming going on and global warming is affecting our winters."

Interestingly, it is unusual for record-low temperatures to be set during cooling cycles. The lowest temperatures typically are set during warming cycles (i.e., the hot summer and cold, wet winter of 1847). This reinforces the idea that global warming causes erratic weather.

What are the Odds?
Science shows that carbon dioxide levels in the atmosphere have risen approximately 53 parts per million (ppm) over the past 40 years. "When I was a high school student, CO2 in the atmosphere was 312 ppm," Taylor says. "Now it's up to 365 ppm."

Of course, carbon dioxide levels are always higher in the winter than in the summer, coinciding with the growing cycles of plants that consume it, and possibly also affected by increased human emissions of carbon dioxide in the winter (i.e., the burning of fossil fuels for heat). "So it varies every year, but overall it's been climbing," Taylor says.

Why is there more carbon dioxide in the atmosphere? According to Taylor, part of the cause is natural and part of the cause is manmade. He explains that some of the increase can be attributed to the natural warming cycle the Earth is currently in. "When the world is warmer, the CO2 will go up," he says. "It just works that way." But the rest is caused by the burning of fossil fuels. "If we're releasing CO2, if we're burning fossil fuels faster than the Earth creates fossils, we're going to raise carbon dioxide," he says, explaining that carbon dioxide is a greenhouse causing gas because, unlike oxygen, it's thermally opaque. These types of gases tend to trap the sun's energy in the atmosphere, causing a warming effect.

This greenhouse affect isn't all bad, of course. Plants grow faster with increased levels of carbon dioxide to feed on, growing seasons are longer and Arctic shipping lanes could open up. But when it comes to more CO2 in the air, most scientists believe the negatives far outweigh the positives. Taylor says he's not sure what the impact will ultimately be, but he's rather certain that serious checks need to be put in place immediately. "There's no question that carbon dioxide is up," he says. "There is little question that it is up substantially and it looks like human activity has about doubled the natural effect during the past couple of centuries. This is a significant thing. We probably shouldn't let our carbon dioxide balance continue to get off kilter like this."

Taylor doesn't pretend to have all the answers, though, and he says the popular theories floated by the likes of Al Gore may be slightly overcooked. "I think people are exaggerating the idea that all of the temperature change occurring on Earth is being caused by this," he says. "They shouldn't be saying that. Because pretty soon we could discover that these things are only partially true. And then people, feeling misled won't do anything. And in fact we should do something about this great change we're causing, if for no other reason than it's not a good idea to change the environment like this when we're not really sure what it will do."

One thing it might be doing, from an agricultural viewpoint, is preventing crop yields from reaching their full potential.

Since the introduction of synthetic fertilizers and hybrid corn varieties, U.S. corn yields have steadily risen. According to Taylor, from the late 1950s through the 1970s, yields were climbing at about 3 percent per year. In fact, in the 1950s, '60s and '70s, there seemed to be little variability in this rate of increase, leading many farmers and crop experts to believe that science had essentially beaten Mother Nature. In truth, Taylor says, farmers were simply experiencing a benign cooling phase in those decades that produced consistently optimal growing conditions coupled with agricultural breakthroughs.

Despite continually terrific gains in corn yields, Taylor says climate change on a global scale—and principally the erratic weather associated with it—has stopped growers from staying on that straight trend line of 3 percent yield growth per year. "We've been improving our technology," he says. "We've been improving our hybrids. We've been improving everything we do, but nature is keeping that trend line down—keeping it lower than what it could be with respect to its potential," he says, pointing out a "kink" in that upward trend line that occurred around 1980.

"Things are consistent during global cooling and erratic during global warming because—and some of it may be coincidence—when the Earth is warming there is more energy on the Earth from the sun," Taylor explains. "The place is simply warmer, and this energy tries to balance itself between the poles and the equator and it does that with convection—ocean currents and air currents."

More heat leads to more convection. More convection leads to a greater chance for warm ocean air to move up into the Corn Belt. It also means there's a greater chance of unseasonably cold arctic air to move down into the Corn Belt. That's what happened in 1988, the last really bad drought year in the Midwest and the hottest year since the Dust Bowl. "We also had frost damage here in Minnesota on June 10 that year," Taylor says. "It was an extreme year. Things were extreme in both directions."

Unfortunately, good years never quite make up for bad years. "I call this the 'riding your bicycle into the wind' phenomenon," Taylor says. "I ride my bike to the office every day. It takes me 12 minutes to get from my house to my office in still air. Last week I had a good, stiff tail wind and I got to the office in nine minutes. That evening it took me 24 minutes to get home. Wind at my back never makes up for what I lose for the wind being at my face. And great crop years never make up for bad ones. The bad years hurt us more than the good years help us."

And with that, everything Taylor is saying really starts to make sense. Global warming is cyclical and does occur naturally. Human-caused greenhouse gas emissions might be significantly accelerating or bolstering the current warming period. Warming periods lead to erratic weather. Now, a bolstered warming affect could lead to especially erratic weather. Erratic weather leads to a greater chance of bad crop years—and good crop years never quite make up for bad ones—setting the stage for a potentially scary near-term agricultural outlook.

After doling out his closing predictions, Taylor picks up a set of dice and pulls up a slide showing this year's actual corn yield risk broken down by the odds he's just shared with the audience. He says, "You can play this game at home and try figure out what's going to happen this summer." He rolls the dice and gets two sixes, which only happens one out of every 36 tries on average. "I just rolled a drought with $7 corn at harvest time," he says as the crowd laughs. Then he rolls a couple of threes—above trend line yield with $3.80 corn. Then he rolls an eight—back to drought and $5.50 corn. "Weather is our greatest risk and we have to treat it that way," he says. "We know what the odds are."

Tom Bryan is the editorial director of Ethanol Producer Magazine. Reach him at tbryan@bbibiofuels.com or (701) 746-8385.