It's true here in the West, where our temperatures are influenced more by warmer Pacific air, and it's true across the divide, which tends to be both colder and warmer at the extremes.
Maybe 5 degrees doesn't sound like much. And really,
What's curious about the warmer temperatures is this - overall, Montana's climate has warmed by about a degree over the same 50 years. That rise roughly mirrors the average increase in global temperatures, and serves to make the 5-degree increase in March stand out all the more.
The increase has climate scientist Steve Running worried. Running, a University of Montana professor in the College of Forest and Conservation and director of the Numerical Terradynamics Simulation Group, spends a lot of time looking at charts and graphs that depict various aspects of climate change.
And when he looks at the March temperatures, he thinks about the chart that shows the average spring snowmelt going off about three weeks earlier than it did 50 years ago. He sees the chart that shows green-up coming earlier each spring.
He sees the satellite photos that reflect five 100-year fire years in the past 15 years. He sees more charts that show more rain and less snow. He sees a 50-year projection showing a March snowline about a third of the way up the mountain at Snowbowl.
“If it was any one thing, maybe you wouldn't worry about it too much,” Running said recently. “But it's everywhere. And it's all connected.”
It's a complex portrait painted by all those graphs and charts, but there's at least one way to look at the March increase that provides some easy-to-understand context.
When western Montana is covered with bright white snow, it reflects the heat of the winter and early spring sun. When it's not snow-covered, that same heat is absorbed by the brown earth. Thus, cold promotes more cold, warmth more warmth.
“That's the inflection that we see in these charts,” Running said. “Less snow, an earlier melt, more rain. March is an important month for us, and these are changes that might change the way we do things here.”
March in Montana is, in fact, a microcosm of what's happening worldwide, at least where ice and snow are concerned. Take Greenland, for instance.
Greenland is pretty much snow- and ice-covered in winter, then goes through a summer melting season. In 1996, about 22 cubic miles of ice melted off during the summer. Last year, nearly 53 cubic miles melted.
So what? you say.
Here's what. Nobody thinks all the ice in Greenland is going to melt as Arctic temperatures rise, of course, but even an accelerating, partial melt could prove disastrous. The ice on Greenland contains enough water to raise the level of the world's oceans by 23 feet.
Even melting 10 percent of the ice sheet would raise the level by more than 2 feet. Now consider that 13 of the world's 20 largest cities are built at sea level.
“There's a lot more fresh water going into the ocean from Greenland now, and it's likely not a good thing,” Running said. “In just a decade, the melt has accelerated considerably there, so the potential to see ocean levels rise is not just some crazy idea that a bunch of scientists cooked up on their computers. It's real.”
Cold begets cold. Heat begets heat.
Now consider this: Antarctica's glaciers are retreating at an accelerating rate, calving icebergs the size of small countries into the sea. The same is true in Alaska. But there's enough ice in Antarctica to raise the oceans' levels by more than 200 feet, though again, no one expects all of it to melt. But what if 5 percent melts?
And this: For nearly 60 years, the United States' fleet of nuclear submarines has kept extremely close measurements of ice thickness in the Arctic.
“What they've found - and this is true all over the Arctic in many, many places - is that the ice is about 40 percent less thick than it was when they starting measuring,” Running said. “That's absolutely huge.”
There used to be a debate about global warming and the role mankind may have played in it. Where warming is concerned, the debate is mostly over, particularly in the scientific community, Running said. There will always be a discussion about the precise role the emissions from fossil-fuel burning have played, he said, and that's a good discussion to have.
“There's virtually no one that doesn't believe it now,” he said. “You'd have to be a pretty bad scientist to not see what's happening.”
But just five years ago, when Running would give what he calls his “little talk” about climate change, he'd get the occasional heckler.
“Inevitably, I'd have some guy out there saying nobody really knows what's happening, it's all just natural variability, it's all some liberal plot,” said Running. “Now I don't get openly challenged about the facts. Mainly people want to know is there anything we can do about global warming.”
The global-warming naysayers are mostly gone, Running said, rousted out by both science and reality. And discussion about the topic is running fast and hot - Time magazine devoted nearly an entire issue to climate change early this month. Nature and Science, two top scientific journals, are rich with papers about disturbing changes brought on by the warming climate.
A couple of recent findings seemed to have cemented the reality that the earth's climate is warming beyond its natural variability, Running said.
“The first thing is that last September, two scientific papers came out in Nature and Science that for the first time connected global warming with hurricane intensity,” Running said. “Those papers just hit like a runaway freight train.”
Those papers, which were already wending their way through the publication process before Katrina devastated the Gulf Coast, linked the ocean's warming to an increase in duration and size of hurricanes.
The second affirmation came in the journal Science just recently - the news about the Greenland ice sheet.
Time magazine then ran a special issue on global warming. “Be Worried. Be Very Worried,” the cover stated.
The main piece was titled, “The Tipping Point,” and that's precisely how Running sees the recent wave of news about climate change.
“We finally have enough information out there, information that crosses so many fields, that it's undeniable,” he said. “If you just had some curious findings in one area, say glaciers, then you could argue that maybe it's just an anomaly. But this is all across the board. This is everywhere. And now it's on fast-forward. We can't wait to talk about it.”
Here are the climate markers Running identifies in his “little talk.”
By the 1960s, scientific observers at the Mauna Loa Observatory began noting a steep upswing in the curve that charted the amount of carbon dioxide in the atmosphere.
“By the mid-'60s, we had a clue that it was going up, and it hasn't gone down one year since then,” Running said. “This is the cornerstone of global warming.”
A similarly disturbing pattern is apparent in the chart that tracks the emission of greenhouse gases being released into the atmosphere. By the middle part of the last century, the curve steepens dramatically; interestingly, the curve fits like a glove with measurements of global temperature, which break through the pattern of natural variability around 1980.
“Over a thousand years, we had some natural variability, but in the past 100 or so years, it starts to climb without really looking back,” he said. “Then, along about 1980, it really starts breaking out. We couldn't really see it then because we were just at the edge of the envelope of natural variability. But you can track the emissions and the temperature very closely.”
The 1980s also serve as an early marker for the increase in hurricane intensity, Running said. Hurricanes aren't particularly more powerful than they used to be, but the number of hurricanes that become dangerous Category 4 and 5 storms is increasing.
“When it does get started, it gets bigger and badder, and it gets there faster,” he said. “The ocean is measurably warmer, and this is one of the effects.”
The oceans - the engine of climate change - have warmed, and they've also risen. Sea level has come up about a foot over the past 100 years, and until recently that had been the projection for the next century as well. Then the news about ice melt came along, and the projections started changing.
“Now we're talking numbers two or three times that,” Running said. “When you think about all the people that live in coastal areas, all the infrastructure, all the valuable real estate, the effects could be devastating.”
In Bangladesh, for instance, a sea level rise of just a few feet could put nearly 20 percent of the country underwater.
The ice melt that is pushing the rise in sea level is well-documented, from submarines to satellites, which have detected a staggering loss of sea ice in the Arctic.
“We are losing the square mileage of about one Montana per decade in Arctic sea ice,” Running said. “It's getting to the point where people are starting to look at the Arctic Ocean as a shipping lane in the summer. It could take the place of the Panama Canal, and that's just unheard of.”
Sea ice and glaciers aren't all that's melting - the permafrost in places like Alaska and Siberia is starting to thaw in some places. People and industry in those areas depend on permafrost being exactly that - permanent and frozen.
“It's essentially the foundation for houses and roadbeds,” Running said. “When it's not frozen, it's a problem.”
And that could be just the tip of the problem. As the permafrost warms and thaws, it may well start to give off in gas form the hundreds of gigatons of carbon stored there.
“That would be a huge release of natural greenhouse gases that would just combine with the gases from fossil fuel,” Running said.
Rivers, too, are thawing out earlier in the far north, altering life for cultures and animals that depend on the pathways frozen rivers and lakes provide. The flip side, of course, in places like Montana and the Northwest, is the number of frost-free days.
“This is one of those areas where there's sort of a good side, too,” Running said. “We have more vegetation growth. Forests are growing more quickly. Agriculture might do better. There are ways we can benefit from a longer growing season.”
Steve Running doesn't want to be a doomsayer. He cringed when the Montana Kaimin, the university newspaper, covered a recent talk with a headline noting that “Climate changes doom Montana life.”
Montana, he said, might even be a place that benefits in some ways from global warming.
“You know, it's been sort of a cold place, and now it's moving away from that,” he said. “You can garden longer, enjoy a longer summer maybe.”
But the benefits may come with a cost.
“The flip side is that if you're interested in winter sports, it's going to get tougher,” he said. “And those frost-free days might not look so good if it gets hotter and we find ourselves with more wildfires.”
Running has a few more numbers to fuel the discussion about what life will hold for globally warmed Montanans. He labors not to place a value judgment on the numbers, which can speak for themselves.
“We labor not to make grandiose pronouncements,” he said with a laugh.
Rain has increased statewide by about 5 percent to 10 percent, while snow is generally decreasing. Missoula, for instance, has about 22 inches less snow a year than it did 50 years ago, Running said. In fact, if the current trends continue, Missoula might never see snow by 2080.
Montana's warmest temperatures are increasing, but not as quickly as our low temperatures are rising. Also, the high temperatures of winter are rising faster than the highs of summer.
“The general message is warmer, and that's particularly true on the low end,” he said.
That's tough news for ski areas that aren't high in the mountains on north-facing slopes.
But the numbers that concern Running most deal with the factors that combine for bad wildfire seasons - early snowmelt, less snow, more rain creating more flammable vegetation and a longer warm season.
“Maybe we get lucky and all of that works out OK,” he said. “But if Montana and the Rocky Mountains face a threat from global warming, it's probably going to come from wildfires. It may be that we have a nice, long summer that we can't get out and enjoy.”
So much of the global-warming future is wrapped in uncertainty, but one thing is becoming clearer to Running.
“From what I can see, people are starting to get this stuff a lot better,” he said. “I think that in the next five years, I'm not going to have to give my little talk anymore. Heck, maybe just a couple of years will do it.”
Reporter Michael Moore can be reached at 523-5252 or at mmoore@missoulian.com
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