Abrupt Climatic Change Coming Soon?

rRaAnNiI writes "Just read an extremely interesting article about the possibility of having a 'little ice age' quite soon - within a decade. The frightening thing is that it makes a lot of sense to me. Does anyone know how to build an igloo?"

Comments

Year without a summer

[Trinition]

Abrubt climate changes aren't new. In 1816, there was no summer. Volcanic side effects from the year before blotted out enough light to cause a winterry year.

Re:Year without a summer

[schmaltz]

If you mean the US, and for only one year, then no.

Can you qualify that with actual information?

Working in a previous life as a software development manager at a major produce distributor, I can tell you the pipeline from farm to stomach is measured in days. Some stocks have maybe a season's buffer; for instance frozen orange juice and wheat. Corn gets stored, but the amount and duration varies from producer to distributer to processor.

The U.S. is more grasshopper than ant. Stockpiles are due to overproduction and market strategy rather than actual preparedness -they are not intentional stockpiles against production interruption. I expect there'd be widespread pandemonium, not just from 'perceived threat', but actual disruption of the entire supply chain that is feeding over 300,000,000 people in the U.S. alone.

What stockpile we do have will probably move quickly. It's very unclear just what percent the U.S.'s "stockpiled" food store is -is it a fraction of the daily, weekly, monthly or annual need? Hard to tell. I imagine the military would get by for a time, but your typical city person, being at the far end of the longer chains, will have a hard time getting their hands on supplies.

scary stuff

[Anonymous Coward]

I saw something on the discovery channel the other night that mentioned the same thing, it was called ocean mysteries or something similar...

Showed how if the planet got just a wee bit warmer, it would frell with the ocean's thermal regulation system and frell it up for a while...

And yes, just a drop of a few degrees will really frell things up! Look at the florida citrus farmers - they are teetering on the edge now. they can't exactly move further south when they want - even a slight freeze, and their fruit is worthless...

if rivers freeze at the wrong time, it could interfere with salmon spanning and the like, causing small cascades in the food web. Oh nature as whole will handle it, though we will suffer during the adaptation...

After all, even one degree is the difference between freezing and melting point, no?

My obersvations

[shimmin]

The idea that a shutting-down of the Altantic Conveyor would lead to drastic cooling in Europe has been tossed around for the last twenty years or so (ever since computer simulations suggested that the patterns of ocean currents are not particularly stable, but are really merely metastable states in a rather easily perturbed dynamic system), and the idea that global warming might cause this (by dumping more fresh water onto the top of the ocean) has been around for the last 10-15 or so, but what's really interesting are the maps of ocean sanility over the past 40 years in the article.

Note that from 1965-1990 (a period of a general mild warming trend globally, depending on whose graphs you look at), the North Atlantic went through a period of exceptional salinity, especially on the eastern seaboard. The article makes no attempt to comment on this.

What it raises alarms based on are the last 10 years of data, in which the North Atlantic appears to be abnormally fresh. Unfortnately, we have no centuries-long data series for seawater salinity at depth, so what the article really means is "fresher than we've seen in the last 40 years," not "fresh is a manner that is historically significant."

But we've been dumping carbon in the atmosphere all century long. If human activity is to blame for the recent freshness, how can we explain the previous salinity when the human activity in question has more or less continued unchecked throughout the whole time period?

Personally, I think the truth is scarier than any environmental alarmism can paint. Articles like this would have you believe that

The climate is a delicate balance that can change suddenly.

Human activity can cause such changes.

Such a change appears imminent.

Therefore we should stop certain human activities to avoid the disaster.

All fine and good, but the truth is more like

The climate is a delicate balance that can change suddenly.

Human activity can cause such changes.

So can a whole lot of other stuff.

Supercomputers and all, we still have minimal understanding of how the climate actually works.

It's possible that major climatic change could happen within the decade as a result of human activity.

But ceasing that activity might not make a difference.

In fact, for all we know, ceasing that activity might at this point cause a climatic change that otherwise would have been avoided.

Chaotic dynamics can make you want to go run to mommy sometimes.

Now may be such a time.

Re:Not as extreme as headline may imply

[weaselgrrl]

While the difference of 5 to 10 degrees may not sound like much given the range of temperatures that we experience in Europe or North America just in a single day much less throughout the year, an average drop of 5 to 10 degrees is very significant and would create agricultural havok.

Crop plants are very sensitive to climative changes and have particular temperature/rainfall ranges in which they thrive. Make the local weather a little too hot, a little too cold, a little too wet or a little too dry and suddenly your fruit trees fail to produce, your vegetables wilt and your grains fail to pests, if they growq at all. Minor changes in the average temperature greatly effects the success of fungus and insects in damaging crops, allowing them to spread into new regions.

To put this into better perspective, during the peak of the last ice age, 18,000 to 20,000 years ago, the average temperature in was about 9 to 12F cooler than today. Even an average change half of that would create dramatic changes in natural plant distribution.

During the so called Little Ice Age from 1650-1850, a 3F temperature drop caused serious crop failure in Europe, leading to famine and disease. And that is just a 3F degree average drop.

Animals are also effected my temperature changes. Here on the Pacific NW coast, salmon require stream temperatures to be within a very delicate range in order to spawn. This is why cutting down trees (which shade the streams) causes a decline in salmon runs. That's just one of many examples.

Humans are much more adaptable to climate change than most other plants and animals. But with 6 billion+ mouths to feed, its not quite clear how we'd adapt to a climatic problem of this kind of scale.

As for the ocean conveyor belt, it naturally seems to have some tiny warming and cooling cycles which in turn effect rainfall and storm formation in many parts of the world. For a nice overview, go here: Climate Rides on Ocean Conveyor Belt. Over the past century+ a 20-year cycle of minor warming and cooling has been found in the conveyor belt, and supposedly the conveyor belt should be in a strong cycle right now, based of previous trends. But is it?

If global warming (natural cycles or man-made) causes too much melting of the Greenland glaciers, all of that extra fresh water poses quite a risk to the ocean conveyor belt.

Perhaps what we should be saying about the steady warming that has happened over the past 150 years is "enjoy it while it lasts."