Gwynne Dyer: Sea ice, climate, food production, and an unknown unknown

It’s no surprise that we will have a record minimum of ice cover in the Arctic Ocean at the end of this summer melt season. It’s already down to around four million square kilometres, with a least another week of melting to go, but this is what you might call a "known unknown". Scientists knew we were losing the ice-cover fast; they just didn’t know how fast.

I’m no fan of Don Rumsfeld, who helped to lead the United States into the disastrous invasion of Iraq when he was George W. Bush’s secretary of defense, but I never had a problem with the distinction he made between “known unknowns” and “unknown unknowns” when discussing the intelligence data. He was brutally mocked in the media for using such jargon, but there really is a difference.

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 of 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 IPCC 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 Center, who thought it might happen in this decade, but nobody actually knew. A "known unknown", in other words.

There were also some assumptions about what would happen next in the Arctic. At first the ice would return each winter, although it would be thinner and less extensive than before, but as time passed the ice-free period would get longer.

A frozen ocean reflects sunlight back into space, but open water absorbs it and turns it into heat, so the ocean itself would now be getting warmer. The warmer water would inhibit the growth of ice even in winter, and eventually the Arctic Ocean would be ice-free all year round—but nobody knew when this would happen.

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.

In a paper in Geophysical Letters last March entitled “Evidence linking Arctic amplification to extreme weather in mid-latitudes", Jennifer Francis of Rutgers University and Stephen Vavrus of the University of Wisconsin–Madison offered a hypothesis that may explain why world grain prices have risen 30 percent in the past four months (and are still going up).

First, 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.

The bigger amplitude means the Rossby waves reach farther down into the temperate zone than they used to, and the slower winds means that the waves take more time to track across any given territory. The weather north of the jet stream is wet and cold (even warmer Arctic air is still pretty cold), and to the south it is dry and warm. And now, many temperate regions of the planet are stuck in one kind of weather or the other for much longer periods.

This is a recipe for extreme weather. In the old days the Rossby waves went past fast, bringing the alternation 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, like the U.S. Midwest and southern Russia, which is why food prices are going up so fast. And this was an "unknown unknown": nobody saw it coming.

All the scenarios that the military of various countries were working with assumed that climate change would hit food production very hard in the tropical and subtropical 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.

If Francis and Vavrus are right, that may not be the case. It’s a most unwelcome surprise—and it may be the first of many.

Comments (15) Add New Comment
DENDEN99
try and get countries and businesses motivated by money to accept that
5
1
Rating: +4
clar matchim
I appreciate much your "launching out into the deep" for pushing understanding of climate change and its implications for eco-systems. In psychology, reference is often made of the Jo-Harri Window to enable insight of self and others behaviour and some parallels of this model I see in your reference to the nomenclature of Rumsfeld.
4
3
Rating: +1
David Pulak
Bulls eye Gwynne. Food inflation is already here in Canada. Seen the price of a decent loaf of bread? The trend is not good, and points to the need for new forms of organization to counter the inevitable. I'm thinking food co-ops who buy grains and other foodstuffs directly from the farmer, thus curtailing the power of multinational food conglomerates. Two birds with one stone I should think. Food activist Susan George has been advocating this for years.
0
3
Rating: -3
miguel
Tectonic plate shift, maybe more earthquakes and vulcanism. Removing that much weight over that much area, is a massive change.
Miguel
0
3
Rating: -3
miguel
Scotland has been rising while southern England has been sinking since the last ice age ended, allowing the crust to spring back.
Miguel
2
2
Rating: 0
Michael Doliner
"A frozen ocean reflects sunlight back into space, but open water absorbs it and turns it into heat, so the ocean itself would now be getting warmer."

True enough, but in the winter in the arctic there is no sunlight and open water radiates heat better than ice.
3
0
Rating: +3
Kim Collins
"It sounds harsh, but in light of these realities, this year’s U.S. drought is good news. The sooner we get serious about climate change, the better our chances of keeping temperatures from rising too high. The drought and heat wave have already led to record corn prices. The world’s integrated grain markets will transmit these higher prices around the world, in time affecting just about everyone.

People may not care much about climate change, but most do care about the price of food because it affects their everyday lives. Fears about imperiled food security may be our best hope for breaking through widespread climate-change denial and generating the political pressure to do something, finally, about the problem."

- Thomas Homer-Dixon, author (e.g. Carbon Shift, The Upside of Down) and director of the Waterloo Institute for Complexity and Innovation (Waterloo University)
1
1
Rating: 0
UrbanSurvivor
FEH..is Venice underwater YET?

NO?..Shocking!

More Commie-Chicken Little-carbon taxes-we-must-DO-something nonsense from the hoi-polloi Kool-Aid crowd.

I remember the 70s when we were told that the icebergs were coming to get us...youre all weasels...looking to destroy the worlds' economies with your lies and wealth re-distribution. Your thumbs down to me is my middle finger to you.
2
1
Rating: +1
Andrea Silverthorne
The Arctic ice and the logically illogical greater increase in temperature in the area can be attributed to the breaking . . .dissociation of methane hydrate. They bring up heat from the deep earh, given they can hold up to 400 degrees F that is a lot of heat. . .and a lot of radiation. Methane is the source of all excess CO2 in the atmosphere. Co2 is what methane oxidzes to. CO 2 is the cover story for methane. Stop methane emissions. We also need to know: Are the oil producing nations are still conducting experiments with methane hydrates trying to harvest the methane with forced dissociation. They did so in 2003, the probable cause of ice melt that then began. Are they sti;ll experimenting with these very dangerous substances.
6
3
Rating: +3
jgnfld
Re. M. Dohliner: Uh, you do know that it is the radiated heat rather than reflected sunlight that the CO2 traps, right?
0
4
Rating: -4
DireTimes
Dyer looks for facts that fit his apocalyptic fantasy of climate alarmism. There will be plenty of food in temperate and tropical regions for a long time to come, in fact North America has not been affected by climate change as much as other parts of the world. Dyer's rantings about this subject are more of an indication of his psychological state rather than truth.
2
1
Rating: +1
Kim Collins
@DireTimes:

Dyer is a military and global security analyst. Climate change is on his radar because militaries around the world recognize it a "threat multiplier" (e.g. http://www.fco.gov.uk/en/global-issues/climate-change/priorities/global-..., http://www.themarknews.com/articles/5085-at-war-with-the-climate/#.UEZU6...).

If you're interested, here's a 2009 interview with Dyer where he explains why he started researching climate change and how he expects it will effect global security and conflict:
http://ww3.tvo.org/video/171087/gwynne-dyer-global-effects-climate-change.

By the way, it doesn't have to be dire times. We can change our ways to adapt to this predicament. Many of us already are and are living healthier and happier lives as a result of it.

“It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is the most adaptable to change.”
~ Charles Darwin
1
1
Rating: 0
Pender Guy
Food is still cheap, very cheap when compared to other resources.
In this country other than those at the bottom it shouldnt be an issue for the average Canadian to absorb any rise in the forseeable future.
However, a perpetual loss of production in the main exporting countries like the US, Canada, Brazil, Argentina and Russia/Ukraine would be catastrophic for many 3rd world countries. Cheap food and goverment subsidies in the West have paved the way for rampant overpopulation in the 3rd world. As some of the comments above I welcome more expensive food for the sake of our planet.
7
6
Rating: +1
Issac Çhandler
not to worry - supply side scientists will save us. Agri multinationals (Monsanto et all) are developing genetically modified foods that survive drought:

http://www.youtube.com/watch?v=-0uls507hvM

http://www.youtube.com/watch?v=QxpH9wBt0fM

http://en.wikipedia.org/wiki/%C3%81rp%C3%A1d_Pusztai#Pusztai_affair

The World According To Monsanto describes how american agencies ( USAIS / CIA and Food and Drugs Agency) and the supreme court of Canada has enabled Monsanto to do good works...
6
5
Rating: +1
Mareyline
The UK was a good example of slower wind this summer (2012) where the London sky was uninterruptedly covered with grey clouds from the beginning of April to mid-August.
5
3
Rating: +2
Add new comment
To prevent automated spam submissions leave this field empty.