An ongoing US Department of Energy-backed research project led by a US Navy scientist predicts that the Arctic could lose its summer sea ice cover as early as 2016 - 84 years ahead of conventional model projections.
The project, based out of the US Naval Postgraduate School's Department of Oceanography, uses complex modelling techniques that make its projections more accurate than others.
A paper by principal investigator Professor Wieslaw Maslowski in the Annual Review of Earth and Planetary Sciences sets out some of the findings so far of the research project:
"Given the estimated trend and the volume estimate for October–November of 2007 at less than 9,000 km3, one can project that at this rate it would take only 9 more years or until 2016 ± 3 years to reach a nearly ice-free Arctic Ocean in summer. Regardless of high uncertainty associated with such an estimate, it does provide a lower bound of the time range for projections of seasonal sea ice cover."The paper is highly critical of global climate models (GCM) and even the majority of regional models, noting that "many Arctic climatic processes that are omitted from, or poorly represented in, most current-generation GCMs" which "do not account for important feedbacks among various system components." There is therefore "a great need for improved understanding and model representation of physical processes and interactions specific to polar regions that currently might not be fully accounted for or are missing in GCMs."
Those of us - well, nearly all of us, who live along Canada's southern border - fail to grasp the significance to our immediate future that the warming Arctic holds. It's not just bad news for polar bears and people who hunt with snowmobiles. It's a far more powerful Arctic atmosphere that whipsaws our own temperature and precipitation patterns. It's the new Polar Jet Stream and the Rossby waves that generates. As Gwynne Dyer put it some months ago:
A “known unknown,” in the case of the Arctic Ocean, is how long it will be before the entire sea is ice-free at the end of each summer. The last report by the Intergovernmental Panel on Climate Change, published in 2007, talked about that happening some time in the second half of this century, but it couldn’t be more specific.
The panel usually underestimates the rate of climatic change, but even the pessimists didn’t think we’d get there before the 2030s. I did encounter one maverick at the National Ice and Snow Data Centre who thought it might happen in this decade, but nobody actually knew. A “known unknown,” in other words.
As for the impact that an ice-free Arctic Ocean might have on climates elsewhere, it would obviously accelerate the global warming trend, but beyond that there wasn’t much to go on. This was the territory of the “unknown unknowns.” Big things might happen to the complex atmospheric system of the planet when a major chunk of it suddenly changes, but nobody knew what.
Now we begin to see the consequences. The polar jet stream — an air current that circles the globe in the higher northern latitudes and separates cold, wet weather to the north from warmer, drier weather to the south — is changing its behaviour.
...a warmer Arctic reduces the temperature gradient between the temperate and polar zones. That, in turn, slows the wind speeds in the zone between the two and increases the “wave amplitude” of the jet stream. The jet stream flows around the planet in great swooping curves, like a river crossing a flat plain, and those curves — Rossby waves, in scientific language — are getting bigger and slower.
This is a recipe for extreme weather. In the old days, the Rossby waves went past fast, bringing the alternating of rainy and sunny weather that characterized the mid-latitude climate. Now, they hang around much longer and generate more extreme weather events: droughts and heat waves, or prolonged rain and flooding, or blizzards and long, hard freezes.
The temperate zone has been seeing a lot of that sort of thing in the past couple of years — much more than usual. It’s cutting deeply into food production in the major breadbaskets of the planet, such as the U.S. Midwest and southern Russia, which is why food prices are going up so fast. This was an “unknown unknown.” Nobody saw it coming.
All the scenarios that the militaries of various countries were working with assumed that climate change would hit food production very hard in the tropical and sub-tropical parts of the world, and that is still true. But the scenarios also assumed that the temperate regions of the planet would still be able to feed themselves well (and even have a surplus left over to export) for many decades to come.
Nobody saw it coming, indeed. Nobody who mattered anyway. Those who did see this coming were derided as alarmists and ignored. Now it is our new reality and what are we doing about it? In Calgary they're looking at building floodways and restricting new construction on their ever-expanding flood plains. Toronto is also talking about finding mechanisms to flow floodwaters into Lake Ontario. That's all well and good but it fixes a problem somewhat, temporarily. It solves nothing.
Why are we not hearing any calls to action from the Petro-Pols of Parliament Hill? Is ignoring this going to make it better for the country and our people or is it merely shrewd politics? Why do I even have to ask?
Post a Comment