For the past few weeks, I enjoyed writing about things I had been mulling over for months. First, it was instinct and faith. Spring is a time of rebirth and renewal for almost everything, and organisms follow age-old clues to schedule their spring events. As we all wait for the relative ease of summer, looking to the sky can be a comfort no matter what you believe is up there.
Then I got philosophical about wind, and how it is both a symbol and a source of unity, freedom, eternity and balance. Most importantly for this time of year, the wind is the Earth’s attempt to find a temperature balance.
Recently, I shared stories of the many amazing organisms (including humans!) that look forward to the maple sap run each year. You can find all these stories on our Facebook page, or our blog at http://cablemuseumnaturalconnections.blogspot.com/.
All the while I was writing, something else was gnawing at my brain as well: an unpleasant, but fascinating understanding of how these three topics, and many others, are connected to each other, and to our actions.
Last year, UW-Madison professor Steve Vavrus and a colleague at Rutgers University published a paper hypothesizing that warming in the Arctic would cause the jet stream to slow down and meander like a river flowing through the plains. This, in turn, transports less warm air from the oceans over the land, and sets up more extreme weather.
The big-picture mechanism for this connection between warm oceans and slow-moving/extreme weather is not too hard to understand. Wind moves from high pressure to low pressure and equalizes temperature differences. When the temperatures are not as different, the wind does not have as much oomph. Melting ice in the Arctic, Professor Vavrus explained, allows heat stored in the ocean to escape to the atmosphere where it changes the pressure patterns.
It came as no surprise to the scientists, then, when record-low sea ice coverage in the Arctic last summer was followed by the coldest March in Wisconsin in 35-40 years, and a cold April full of slow-moving blizzards. Professor Vavrus acknowledges there is some natural fluctuation of the circulation patterns, and that weather and climate are different things, “But we're arguing the loss of sea ice is ... loading the dice in favor of a more negative Arctic oscillation pattern.” It is loading the dice in favor of extreme, unusual, and sometimes unpleasant weather.
The same meandering jet stream, he noted, could also explain the unusually warm spring in 2012. If a meandering jet stream is like a river, some bends are favorable to cold spells; others are favorable to extreme warmth. Either way, these unusual weather patterns are symptoms of climate change.
While we might be frustrated by the snow this spring, last spring people preparing to tap maple trees were just as disappointed by the early heat wave that severely shortened sap season. Cold nights are necessary for strong sap flow, and early bud-break stops it.
Wisconsin is one of the highest sap-producing states, and the crop value of syrup can be over $5.8 million a year. The value of this ancient tradition in terms of cultural history is immeasurable. You can read more at www.climatewisconsin.org.
This year, reports from tappers both old and new all point to the fact that this is just a weird year. As temperatures fluctuate from warm enough to cold again, the sap starts and then stops flowing. High winds steal away heat that trees absorb from the sun, slowing sap flow. Some sugarbushes are reporting record sap flows already, while others have not even started.
Maple trees respond to temperature to cue their sap flow, but other organisms rely on day length and sunlight intensity to prompt spring events. Many creatures in each category rely on each other for food, pollination, or other symbiotic services. What happens, then, when the day length and the temperature do not match up like the creatures expect? Will their faith in the progress of spring serve them well? Or will old instincts not work in a changing climate?
These are heavy questions to ponder, as I trudge through the slush with sleet pelting my face. The balance brought by wind, the comfort of the sky, the renewal of spring…will these change, too?
For over 45 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The current exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.
Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com/.