Thin Ice

In a town that is known as ‘winter city’ and derives most of its tourism income from this picturesque concept, climate change is a hot topic.
It is early February. Ice has finally frozen solid. Construction of a veritable playground on the adjacent frozen lake has begun.
In winter, this town centers on the lake and it has become an intrical part of my own life as well. I walk across it to school and any other activity that requires going into town. It cuts my travel time in half crossing the ice rather than using the footbridge that connects our island to the mainland.
Nonetheless it’s still a 20 minute walk. That gives me plenty of time to contemplate the state of the 20-30 centimeters of ice that separates me from the lake’s cold waters.
When I fist arrived in mid-January, the ice was unsafe. There were huge soft spots. Water freely flowed under the footbridge. The lake finally froze in mid-December. However, it later thawed and refroze only recently.
On one of my recent forays, I started to wonder if it was normal for the ice to freeze this late. Is this just an unseasonably warm year? Or am I witness to the effects of a long-term warming trend.
Another question rolled around in my head: What would global warming mean for this area?
Seeking answers, I recently sought out Andreas Gyllenhammar. His job is monitoring climate change and how it directly affects Jemtland.
I went to meet Andreas on gray day that felt more like late March than mid- February. A light drizzle of sleet fell spitefully from the sky. The ice looked shakey at best. I took the longer route.
“Statistically it has to be a blip,” Andreas explained regarding this year’s warm weather. “Otherwise it’s really scary. If it’s a trend, then we don’t understand the climate, then something is really really wrong here.”
He pointed out that climate models forecast a gradual warming trend for the region. “That’s the only way to rule out years like this year,” he said.
According to those models, Jemtland is basking in a warm weather “blip.” That assumes the models projecting slower rates of change are sound. Not everyone shares that view.
“Some people think that this is happing faster then we think.”
As it turns out, Andreas uses the lake as an index tracking other warming trends. The lake’s freeze and thaw patterns have been recorded for the last 170 years.
Since 1870, according to the data, the lake’s mean date for thaw is May 18.
Andreas showed me a graph of the thaw dates. There were several deviations, so called “out liars” in statistical parlance, reflecting years when the lake’s thawing bucked overall year-to-year patterns. Since the 1970s, however, the tend shows the lake’s ice gradually thawing earlier.
“Thawing is a better climate parameter, then freezing,” Andreas explained, “freezing takes special conditions: very cold and no wind.” This means the lake’s freeze-up dates more often varies for reasons other than temperature.
The climate in Sweden is getting warmer faster on average then elsewhere in the world. (http://www.ipcc.ch/)
Ostersund spends half of the year below freezing; current projections about the warming trend indicate that in 80 years the Jamtland’s climate will be 5-7 degrees warmer. This would boost the area’s mean temperature to what’s now seen in the southern tip of Sweden, a region comparable to our Pacific Northwest.
“Those months where we are below zero are disappearing,” said Andreas, as he searched for another diagram illustrating projected temperature changes. “So my theory is that Ostersund is in a bad area because we still have winters, but they are disappearing.”
On my walk home, I found myself thinking about what he had said about
Losing winter.I grew up in Anchorage. Part of my identity is built around winter. What would my world be like without snow? The identity of the people here is also intertwined with ice and snow. When climates change, everything else does too. Seasonal patterns are shattered. Biodiversity of a whole region is subject to upheaval. However a more immediate concern to me was loss of my shortcut to school and the vast play ground that the lake provides.