Winter Getting Shorter

[Stratos Ferric]

http://news.bbc.co.uk/1/hi/sci/tech/5279390.stm

The report, based on data from across Europe, concludes that on average winter is now about ten days shorter than it was thirty years ago, that's around 10% of winter gone.

"The team examined 125,000 observational series of 542 plants and 19 animal species in 21 European countries from 1971 to 2000."

Fairly compelling stuff, and it makes neatly a point we were discussing in one of the other threads this week, that corroborating data from nature is an important factor in assessing trends. Note that this study is reporting only on consequence, not cause. The climate is clearly warming, but this study is not designed to indicate causation.

There is a strong argument, if you imagine a curve of temperature vs times, for saying that a shorter winter must also mean a warmer winter (on average). For this not to be the case there would need to be an acceleration in the rate of warming and cooling at the ends of the season.

Interesting stuff.

[cheeky_monkey]

im surprised it only 10 days shorter....feels like 3 months shorter 2 me!

[Shiny_Bottom_1]

Although I can see logic within that report, I do wonder about how they came to that conclusion.

Seasons are usually set by meteological or astronmical terms. Weather within those seasons, arent exclusively within those dates. A perfect example would be that we, over the last few years, have experienced snow outside of the winter season.

We have always had 'unseasonal' weather, so isnt the report just another spin off global warming (i.e. using the same data ype, but expressing it a different way)?

[J10]

Whilst not denying the original point which is probably true.

An irony is that the best wintry weather for the November 05 - April 06 period occurred in November and March certainly locally and I suspect for many across the UK.

[Thundery wintry showers]

I think their arguments are based on growing season terms, with the plants behaving as if the winter is shorter, resulting in a longer growing season.

I remember a Philip Eden article in the Telegraph talking of a 6C threshold for plant growth, and noting that 8 out of the 10 Marches during the 1990s exceeded a value of 6C CET, whereas in earlier decades it happened less often than not. (In the 2000s, we've had 5 out of 7, with 2001 and 2006 not making the cut). Thus March has become more of a month in which plants can start growing earlier.

I think that's what they're getting at.

As for 2005/06, it was certainly the case that in Yorkshire and Tyne & Wear, March had at least as much snow as the other months put together. However, the three main winter months did not approach the above 6C threshold, and late November was cold and, in places, snowy, so the result was a delayed growing season.

[Summer of 95]

The two biggest snowfalls of the 21st century here have both been in March- it's the only month to have produced more than 3cm of lying snow since 1998.

More so than winter getting shorter, autumn these days seems to have been reduced to a week or so of frosty, foggy weather in mid-November, as opposed to the 2-3 months of steadily cooling weather with misty, then foggy and later foggy and frosty mornings, followed by crisp afternoon sun which I remember being more usual up until the mid-1990s.

[The PIT]

Sadly studying a too short time span. In the life time of earth it's just milliseconds .

Edited August 25, 2006 by The PIT

[davehsug]

I was saddened once again that the reports on the TV this morning asserted as a fact that this was caused by man & that plants which failed to adapt would die. Surely the fact that they were growing 2 weks earlier showed that they had adapted!

dave

[Stratos Ferric]

Although I can see logic within that report, I do wonder about how they came to that conclusion.

Seasons are usually set by meteological or astronmical terms. Weather within those seasons, arent exclusively within those dates. A perfect example would be that we, over the last few years, have experienced snow outside of the winter season.

We have always had 'unseasonal' weather, so isnt the report just another spin off global warming (i.e. using the same data ype, but expressing it a different way)?

As TWS suggests, and as I quoted in my post at the top, the analysis is based on the recorded dates of certain specifically discernable features of a wide range of species e.g. first flower open etc. From one year to another these dates vary, just as, say, the date of the last frost / last snowfall does. What they are looking at is the trend; I assume they'll have run a regression throught the different data sets. The size of the sample is enormous, statistically it is beyond being unequivocal.

Sadly studying a too short time span. In the life time of earth it's just milliseconds .

That's a silly comment PIT: the terms are clearly stated. In the reference period (thirty years) the winter season has shortened - the fact that this is very short time period in the geological span is as relevant as is the price of fish. They are not going on to make any extrapolations regarding whether this is indicative of anything else, in fact they seem to have been particularly careful not to go there at all.

I was saddened once again that the reports on the TV this morning asserted as a fact that this was caused by man & that plants which failed to adapt would die. Surely the fact that they were growing 2 weks earlier showed that they had adapted!

dave

If you saw those reports then I suspect they were secondary. If you think about it the analysis would have to use species that had managed to cope, you can't compare a living plant with a dead one. There would be no value in using species that declined. There are species (flora and fauna) that will suffer from a warmer climate; some will migrate polewards, but not all are able to do that, or to do so quickly enough. If, say, you're an alpine that requires cold weather for seeds to germinate, like the arctic poppy, a warmer climate will wipe you out. On the whole the biomass benefits in terms of growth, and this rather mischievious argument was the basis of the Oregon petition in the US that is often misattributed as being a petition against the presence of GW, when its wording is actually that GW, if present, would not be a bad thing because the growing season would be lengthened and yields would increase (this latter, by the way, is not necessarily true because it assumes no change in rainfall, particularly in existing grain belts). The whole ecosystem is delicately balanced, and has evolved slowly; one of the big problems with current warming is that it is happening so rapidly that, were it to continue, the ecosystem is bound to have to re-equilibrate, and that process will favour some species and hurt others.

[Shiny_Bottom_1]

Thanks TWS and SF. I understand that part better.

I hope i've read this better, and just playing a little devils advocate.

Spring is starting earlier by 6-8 days

Autumn is starting later by 3 days

So I see where the 'winter is 10 days shorter' theory.

But, and perhaps I havent read the report correctly, there is no actual mention of neither winter, nor when the seasons end.

So is winter actually getting shorter, or is just Autumn getting shorter, or perhaps spring getting longer.

In other words, is it GW or season shifts (i'm not denying GW at all, just trying to look at the report in different respects)?

Of course, it could be the news article that gives the impression to me, where as the report itself does give evidence of shortening winters.

[The PIT]

That's a silly comment PIT: the terms are clearly stated. In the reference period (thirty years) the winter season has shortened - the fact that this is very short time period in the geological span is as relevant as is the price of fish.

Not a silly comment climate varies per year per decade per century. Whats the title of the piece Climate Change. It was only in the ninties that we getting heavy Snows later in the year. In fifty years time it could have shifted back again. The last bit of your sentance is the silly comment as the lifetime of the Planet has to be considered and it's very relevant.

[Devonian]

Not a silly comment climate varies per year per decade per century. Whats the title of the piece Climate Change. It was only in the ninties that we getting heavy Snows later in the year. In fifty years time it could have shifted back again. The last bit of your sentance is the silly comment as the lifetime of the Planet has to be considered and it's very relevant.

Not if you want to compare like with like. You don't have to go far back in time, say to when the Isthmus of Panama closed, to find times when climate then is simply not comparible to now becuase the basic set up wasn't the same.

You'd need to compare like cars using different fuels, if you wanted to say anything about what effect different fuels have.

[Stratos Ferric]

Not a silly comment climate varies per year per decade per century. Whats the title of the piece Climate Change. It was only in the ninties that we getting heavy Snows later in the year. In fifty years time it could have shifted back again. The last bit of your sentance is the silly comment as the lifetime of the Planet has to be considered and it's very relevant.

PIT, I accept all that, but you're missing the point. The title of the piece (on the BBC site) will have been put there by the journalist / compiler. The STUDY itself covers a thirty year period, I say again, a THIRTY YEAR period. All the authors are saying is that in that thirty year period winters have got shorter; there is no need for any further extrapolation. I agree with all the points you're making, but you might as well be quoting cancer stats during a debate about Manchester United's rise in football over the past 15 years.

Statistically the lifetime of the planet is NOT relevant, though the variation of climate across that time arguably is. In that regard however, the simple fact that the climate has, hitherto, bounced within certain bounds does not mean that it has to stay in those bounds. The longer the period assessed, the wider the variation should become, and in any case, if the components of the system are changed then there is no reason whatsoever why new bounds (limits) should not be established.

Our climate may, indeed, bounce back, but right now by any measure it's not looking likely; not impossible, just not the likeliest outcome.

Not if you want to compare like with like. You don't have to go far back in time, say to when the Isthmus of Panama closed, to find times when climate then is simply not comparible to now becuase the basic set up wasn't the same.

You'd need to compare like cars using different fuels, if you wanted to say anything about what effect different fuels have.

Precisely, and what ought to be alarming to us all is that in the modern record the rate of warming is unmatched, especially if you remove reflux from a period of cold. The current warming is from a base that, in the meso-scale, is NOT cold.

[snowsure]

...The STUDY itself covers a thirty year period, I say again, a THIRTY YEAR period. All the authors are saying is that in that thirty year period winters have got shorter; there is no need for any further extrapolation. I agree with all the points you're making, but you might as well be quoting cancer stats during a debate about Manchester United's rise in football over the past 15 years.

Good points as ever.

Whenever the debate gets to a certain point I always look for something fundamental that may be overlooked.

2 points spring to mind:

1 - A 30 year study (5 years less than my age) has attached to it percpetions that may not be true. When I was 8 years old, the snow was HUGE due to my diminutive size compared to now. To be in the snow for 1 hour felt like being in a winter wonderland for about 10 days. I therefore concur with the spirit of the study.

2 - It is easy to be too local on this issue. Many places (especially the East of Scotland) still receive regular dumps of snow every year. I keep reminding myself that a decline in snowfall across the coutry does not mean a decline in snowfall everywhere (either across our country or further afield)

In much the same way as a news report declaring that average earnings have increased seldom means that I am paid more next month!

[Stratos Ferric]

Good points as ever.

Whenever the debate gets to a certain point I always look for something fundamental that may be overlooked.

2 points spring to mind:

1 - A 30 year study (5 years less than my age) has attached to it percpetions that may not be true. When I was 8 years old, the snow was HUGE due to my diminutive size compared to now. To be in the snow for 1 hour felt like being in a winter wonderland for about 10 days. I therefore concur with the spirit of the study.

2 - It is easy to be too local on this issue. Many places (especially the East of Scotland) still receive regular dumps of snow every year. I keep reminding myself that a decline in snowfall across the coutry does not mean a decline in snowfall everywhere (either across our country or further afield)

In much the same way as a news report declaring that average earnings have increased seldom means that I am paid more next month!

SS,

The above may be valid points, but they certainly don't invalidate the study and its reported findings, though I'm not quite sure what you mean in your first point. If your inference is that the study somehow uses perceptions of what happened when then I think you need to go see some original scientific field study papers. Be assured, to be reported in a technical journal the method will be robust, i.e. based on measured events NOT people's reports or recall of what happened when.

Re point 2, the report does not measure snowfall, in factl so far as I am aware it doesn't mention snowfall at all. It inferentially reports on temperature (this becauae plants respond fairly precisely to temperature, so changes in growth paterns reflect changes in temperature (yes there are other factrs too)), and that's as close as it gets to meteorology.

The reason why it's of meteorological interest is because it corroborates other met based studies and data.

[The Enforcer]

Too right winter's getting shorter: it ended ten years ago.

[Guest Daniel]

http://news.bbc.co.uk/1/hi/sci/tech/5279390.stm

The report, based on data from across Europe, concludes that on average winter is now about ten days shorter than it was thirty years ago, that's around 10% of winter gone.

"The team examined 125,000 observational series of 542 plants and 19 animal species in 21 European countries from 1971 to 2000."

Fairly compelling stuff, and it makes neatly a point we were discussing in one of the other threads this week, that corroborating data from nature is an important factor in assessing trends. Note that this study is reporting only on consequence, not cause. The climate is clearly warming, but this study is not designed to indicate causation.

There is a strong argument, if you imagine a curve of temperature vs times, for saying that a shorter winter must also mean a warmer winter (on average). For this not to be the case there would need to be an acceleration in the rate of warming and cooling at the ends of the season.

Interesting stuff.

As I keep on saying this warmth is just a natrual phase were are going through in which will soon come to an end. Further more if part of this study was done in or near large cites then the heat island effect will have to be taken in to account. Of course in big cities leaves would come out sonner on trees than then open country side. this is because the citty is warmer than the country. During July heat wave night time temps were higher in London and other big U.K cites than the country.

[Methuselah]

As I keep on saying this warmth is just a natrual phase were are going through in which will soon come to an end. Further more if part of this study was done in or near large cites then the heat island effect will have to be taken in to account. Of course in big cities leaves would come out sonner on trees than then open country side. this is because the citty is warmer than the country. During July heat wave night time temps were higher in London and other big U.K cites than the country.

Thank you for that Daniel. But, I'm sure that, like you and I, the scientists involved will have taken all that into account?

And, as far as the natural phase claim: none of us knows for sure whether it is true or not?

[Stratos Ferric]

As I keep on saying this warmth is just a natrual phase were are going through in which will soon come to an end. Further more if part of this study was done in or near large cites then the heat island effect will have to be taken in to account. Of course in big cities leaves would come out sonner on trees than then open country side. this is because the citty is warmer than the country. During July heat wave night time temps were higher in London and other big U.K cites than the country.

Daniel;

The study will NOT have been done in or around big cities. Even if it had, are youhonestly trying to suggest that the UHI effect has increased significantly in the past thirty years? I suspect these scientists are rather more advanced in spotting the obvious methodological baddy creeping up behind the on the stage than you give them credit for.

There's a definition of stupidity that we often use with clients, don't know where the quote comes from, and can't really think why you make me think of it, but anyway...Stupidity is doing the same thing over and over, and expecting the result to be different.

[Stratos Ferric]

More grist for the mill...

http://www.cleartheair.org/seasoncreep/index.vtml

Click and read the report. More data than you can shake an early sprouting Canadian maple branch at.