That is so not the reason why the fall colors were delayed. The leaves changing color depends on how much sun light they get and temperatures that they experience.

Last year was the earliest fall in the northeast in a long time because of a cold rainy October and this year was the warmest October. This is a really good site to see the the differences between this year and last year (check archives).

http://www.foliagenetwork.com/reports/northeast_us/

I only notice EARLY leaf drop trends rather than more delayed ones. The last time I remember a fall like this is about 10 years ago in 1998, around the time of the last minimum if I'm correct?

Anyway this past October was the warmest on record and hit headlines! Here in northwest Jersey it has been much more like December. The higher elevations here have gotten 10" inches of snow this month and they average about a coating usually. I was stuck in the 30's for serval days in a row and it snowed for 3 DAYS in a row. I didn't see any headlines for this? November should end up being one the top coldest for northwest Jersey and if it is not then our records are being tampered with...

Also last years fall foliage was the earliest in atleast the last 10 years according to that site. The leaves last year were off of the trees before Halloween and this year they were green for Halloween. Is someboday seriously going to tell me that its C02? Come on. As C02 goes up the time of the fall peak has gone up and down and up and down.

Nobody in here can tell me that the leaves have remained on the trees for 25 days this year from last year because of C02.

Brett, I do not live in Europe but I do know that the northeast does not fit well into this delayed fall color.
Reply: I do not agree Darren, not from what I have seen and heard.

Another reason is WHY IS IT ISOLATED TO EUROPE? Wouldn't it affect the the whole world? Hence "global warming", oh yeah sorry, the IPCC said it that global warming is limited to certain areas. What a bunch of bull.

Why can't people come up with a more rational reason then global warming? We blame GW on everything we can think of! It is possible the gulf stream that delievers a moderate climate to entire continent could be the cause? Or the sun? Percession? That's a biggy! The earth's wobble on is axis will eventually make June winter and January summer! That would explain delayed winters and delayed springs! And unlike AGW, percession is ACTUALLY happening!

Happy Turkey day to all and enjoy the time with your family! Eat lot's and sleep later! ;)

Nice to see some science related to CO2 where the authors are able to focus on the evidence and produce logical conclusions.

I would think that the warmer nighttime temperatures much of Europe has experienced would also be a contributing factor. When I lived in England as a child, frosts seemed to be more common than they have been the last couple of decades.

Hey, here's an idea! Maybe if the CO2 levels get high enough, the leaves will stay green and on the trees and it will never snow again!!!..WOO HOO!!! I'd be doing back flips in the middle of Heinz Field!!!!! Time to rev up the SUV!!! Dare to dream, as it will NEVER happen, even with all of this gloom and doom nonsense.

By the by, Happy Thanksgiving to everyone! Even to our bitter progressive alarmist UN/Al Gore worshiping friends. Here's hoping they enjoy saving the earth as they eat their tofu turkey.....;-D.....

I'd rather sweat and swelter than shovel, shiver, slip, slide and scrape. BRING ON THE GLOBAL WARMING!!!!!

Adrian Grenier wants to give thanks to a slightly bigger Entourage than usual. "I'm thankful that we still have an Earth so I'm thanking the Earth," he said.
http://www.foxnews.com/story/0,2933,312545,00.html

Our children have been terrorized by the Al Gore fear mongers. They actually believe that CO2 is going to destroy the earth. Not difficult to imagine how that impacts a teenager's thought process "we are all going to die pretty soon anyway, so we might as well....."

Hopefully these people will wind up in jail for the damage they are doing to our children's futures. Children deserve better than fear and hopelessness. Chinese and Russian children are not troubled by this global warming hysteria.

How do you describe someone who makes tens of millions of dollars scaring children?

The frenzy over the so-called reasons for global warming is redicluous. Changing leaf color?? Give me a break, this is an assault on my intelligence. Tell me, what is the average time each species of tree changes leaf color? I want to see the average +/- the standard deviation over the past "several decades" and does that value statistically differ from the most recent measurements across tree species and climate zones.

Reply: the study is talking about CO2, not global warming causing the delay.

Change in leaf color, like most of these so-called "indicators" or "reasons" for global warming, is BS shoveled out typically by liberals in journalism and politics.

Stop shoveling the liberal BS and use your head.

Marie asks:
How do you describe someone who makes tens of millions of dollars scaring children?
"Contrarian"? "Republican"?

Brett interrupts D. Brown's excellent rant to say:
the study is talking about CO2, not global warming causing the delay.

Dang, Brett, there you go again.

You mean you expect to people to actually READ what you post? You mean you expect people to actually respond to WHAT THE AUTHORS WRITE?

For those who are interested, the full text of the paper (Temporal dynamics and spatial variability in the enhancement of canopy leaf area under elevated atmospheric CO2) is available (for a fee) from the publisher.

Here is its abstract:
Increased canopy leaf area (L) may lead to higher forest productivity and alter processes such as species dynamics and ecosystem mass and energy fluxes. Few CO2 enrichment studies have been conducted in closed canopy forests and none have shown a sustained enhancement of L. We reconstructed 8 years (1996-2003) of L at Duke's Free Air CO2 Enrichment experiment to determine the effects of elevated atmospheric CO2 concentration ([CO2]) on L before and after canopy closure in a pine forest with a hardwood component, focusing on interactions with temporal variation in water availability and spatial variation in nitrogen (N) supply. The dynamics of L were reconstructed using data on leaf litterfall mass and specific leaf area for hardwoods, and needle litterfall mass and specific leaf area combined with needle elongation rates, and fascicle and shoot counts for pines. The dynamics of pine L production and senescence were unaffected by elevated [CO2], although L senescence for hardwoods was slowed. Elevated [CO2] enhanced pine L and the total canopy L (combined pine and hardwood species; P < 0.050); on average, enhancement following canopy closure was ~16% and 14% respectively. However, variation in pine L and its response to elevated [CO2] was not random. Each year pine L under ambient and elevated [CO2] was spatially correlated to the variability in site nitrogen availability (e.g. r2=0.94 and 0.87 in 2001, when L was highest before declining due to droughts and storms), with the [CO2]-induced enhancement increasing with N (P=0.061). Incorporating data on N beyond the range of native fertility, achieved through N fertilization, indicated that pine L had reached the site maximum under elevated [CO2] where native N was highest. Thus closed canopy pine forests may be able to increase leaf area under elevated [CO2] in moderate fertility sites, but are unable to respond to [CO2] in both infertile sites (insufficient resources) and sites having high levels of fertility (maximum utilization of resources). The total canopy L, representing the combined L of pine and hardwood species, was constant across the N gradient under both ambient and elevated [CO2], generating a constant enhancement of canopy L. Thus, in mixed species stands, L of canopy hardwoods which developed on lower fertility sites (~3 g N inputs m−2 yr−1) may be sufficiently enhanced under elevated [CO2] to compensate for the lack of response in pine L, and generate an appreciable response of total canopy L (~14%).

Sadly, it does not fit on a bumper-sticker. Even worse, it is merely factual and describes actual results of an actual experiment performed by actual scientists. How dreadfully dull.

This is not born out by my experience here in Minnesota. 2006 was a very cold September and October, and the leaves changed and dropped very early.

THis year, drought and a cold early September started the leaves changing early, but the very warm weather in late September and October, especially at night delayed color drastically, especially in the CITY which is always warmer. I don't think the CO2 varied that much.

2005 was warm and leaves were leate. 2003 and 2004 were near average and so were the leaves.

Looks like the MWP was no myth.

Sorry Mann

COMBINING MANY MEASUREMENTS SHOWS THAT THE MIDDLE AGES WERE WARMER THAN NOW

Journal abstract and graph below:

Energy & Environment, 2007

http://www.ncasi.org/publications/Detail.aspx?id=3025

Oiznop

I like winter cold and gloom, as long as I have a heated house to retreat into.

The amount of sunlight a tree gets over the season is a constant. The variable is temperature ,and increasing co2 concentration is a trend. If the research shows leaf longevity as a result co2 then that's difficult to qubble with! A logical feedback of this is a lower albedo later in the Fall which means higher temperatures. In the Northeast, warmer Autumns have become the norm.

Sorry I made a small error in my last post, I left out the word SOLAR minimum:

I only notice EARLY leaf drop trends rather than more delayed ones. The last time I remember a fall like this is about 10 years ago in 1998, around the time of the last SOLAR minimum if I'm correct?

Let's see now, leaves staying greener for longer means more oxygen produced in a year and more carbon captured due to a slightly longer growing period. Looks like a negative feedback happening but don't expect it to be portrayed as such. Let's turn it into another boogeyman and pretend only bad things will come of this! That will grab the headlines and the dollars will flow!

God says, "While the earth remains, seedtime and harvest,and cold and heat, and summere and winter, and day and night shall not cease." Genesis 8:22
Give Thanks to whom thanks is due. Happy Thanksgiving.
Of course you wouldn't get to keep your job with global warming if you and they believed that.
LOL

Looks like Japan had a record set in November:

A woman clears the way in front of a store in Aomori on Thursday after heavy snow blanketed northeastern Japan. Snowfalls in the Tohoku region, Hokkaido and Niigata Prefecture hit record levels for November. In the Tohoku region, 30-50 centimeters fell from Wednesday through Thursday morning. (KENICHI HATO/ THE ASAHI SHIMBUN)

It must be the warm November causing the heavy snowfall, because everyone knows that global warming causes increased snowfall.

Let's see! Through photosynthisis green leaves turn CO2 into O2....I would then think that if the leaves stay green and viable longer, then they will be converting more CO2 into O2 and thereby consuming a portion of the 'excess' CO2....and this is bad?

Again, many thanks to the Excellent bt for his cutting and pasting of the paper abstract for our perusal. I'm grateful for him being able to take time out of his busy life to keep us informed. I am particularly overwhelmed by his fantastic synopsis of the paper. Well done, bt!!

The way I read it, these forests react positively to increased CO2 by showing an increase in leaf production. I'm unable to fathom how this is a bad thing. Anyone?

I'm under the impression that in the perfect world of the AGW zealot, the world must fit into the tight little box they have christened "normal". Anything outside of this "norm" is considered undesirable and must be dealt with accordingly with some sort of engineered "fix".

Thank you, Al Gore!!

One thing left out of the equation is soil temperature. Everyone wants to jump on board and point fingers at air temperature, and figures that's what drives leaf development and leaf drop.

Leaves don't emerge in the spring until soil temperature reaches a point that the roots can effectively transport liquid. Ever notice the lag time between spring temperatures and leaf development?

The same can be said for leaf drop. There is a time lag between soil temperature drop and leaf drop.

I'm not saying that CO2 isn't a contributing factor, but its not the only factor.

cbmclean: I like winter cold and gloom, as long as I have a heated house to retreat into.

Its this kind of prudence that is putting our delicate, fragile earth in peril. You are hurting the climate change movement by mentioning preposterous notions such as heating your house. Dont you realize that your selfishness is also heating the earth?

Because of people like you, the forecast is saying 17 degrees tonight in NH, 1 month before the start of winter. It could be 16 degrees, were it not for AGW. Thanks to your type, the temperatures are wicked warm up heya. Knock it off. Why dont you just wear winter clothing while inside? You could save the earth!

Heres a woman that most of global alarmist could warm up to:
http://www.dailymail.co.uk/pages/live/femail/article.html?in_article_id=495495&in_page_id=1879

Thank God she will not be multiplying. No need to procreate her ignorance. I posted this just to show how wide spread and popular this lunacy is. Yesterday I heard some movie star was begging us to drink rats milk because it was better for the environment than drink milk from a cow. You can take your rats milk and two pieces of toilet paper straight to the luney bin. Mad. This world is going mad.

This article appears to have changed the reason that reduced sunlight is the major cause of leaf losing their colors.
"The timing of color change and leaf fall are primarily regulated by the calendar, that is, the increasing length of night. None of the other environmental influences-temperature, rainfall, food supply, and so on-are as unvarying as the steadily increasing length of night during autumn." ( http://na.fs.fed.us/spfo/pubs/misc/leaves/leaves.htm.)

Is this a real change in our understanding or a more "profound" view of the event to involve CO2 for obvious reasons?

Brett,

I'm shocked at your inability to see through the poor research methods by some scientists.

Let's rehash what these scientists are doing. They hypothesize that increased CO2 concentrations are causing a delay in the color change of leaves. Supposedly this delay is based on our experience of when the leaves change color. Assume CO2 concentration right now is 380ppm and CO2 concentration 25 years ago (supposedly when those people remember the leaves changing color sooner) at 340ppm. Those numbers seem to correlated to literature.

The PROPER experiment would have been to have one forest area exposed to CO2 levels of 340ppm and the other exposed to CO2 levels of 380ppm. If there is then a delay in the leaves changing color in the higher CO2 concentration forest area, then AND ONLY THEN can they conclude that the CURRENT delay in the changing of the color of leaves is due to increased CO2 concentrations.

These scientists investigated what happens when a forest is exposed to CO2 levels that differ by 175ppm. Just because that difference in concentration exhibits a delay in the leaves changing color does NOT mean a difference of 40ppm will also exhibit a delay. Additionally, when these trees are shocked with 550ppm of CO2 there may be a different response than when trees witness a much more natural gradual change in CO2 levels.

I guess that nasty CO2 hasn't gotten that bad in southeastern PA yet. The leaves have dropped per the normal reasons leaves drop, shortening days, declining intensity of sunlight, cooler weather. Due the glorious warm October we had this year, the trees and plants stayed green a little longer, and my perennials and annuals kept growing. There was nothing dramatic though. Every year I have been here, it has been different. This past week however, the leaves started dropping like crazy and Thanksgiving night when the cold front came in with wind and much colder weather, the leaves really came down. My deck and driveway and the street are covered. Most of the leaves are off the trees that normally lose their leaves. Beeches keep their brown leaves most of the winter. Also had one of the most beautiful long lasting fall foliage periods since I moved here 10 years ago.

Bad news for BT: per his response to Marie.
How do you describe someone who makes tens of millions of dollars scaring children?
"Contrarian"? "Republican"?

He isn't going to be able to point to Republicans as being the richest any longer.

"Apparently, a new study out shows that the Democrats are the party of the rich.
Democrats like to define themselves as the party of poor and middle-income Americans, but a new study says they now represent the majority of the nation's wealthiest congressional districts.

In a state-by-state, district-by-district comparison of wealth concentrations based on Internal Revenue Service income data, Michael Franc, vice president of government relations at the Heritage Foundation, found that the majority of the nation's wealthiest congressional jurisdictions were represented by Democrats."

Probably making their money from Global Warming grants and earmarks. oops, did I say that?

I agree Chris. If increased CO2 is causing
increased photosynthetic production, would it not offset increased CO2? Within reason of course as anything can become a vicious cycle. Perhaps though, on a global scale, we may see faster recovery of denuded / deforested areas thus resulting in more CO2 captured and thus a leveling off (also depending if people stop
ignorantly devastating forests and use sustainable practices instead.)

I also am in Northwest Jersey and yes the leaves are delayed this year. It is very obvious as there is still brilliant color in some areas remaining. But this summer was very cool from Spring into September (there better be a blue spot over Jersey on the map). And probably the
most beautiful in my 47 years. Few 90+ days.
So we had an extended Indian Summer (remember those?)The leaves were dropping early without color until fall where it was milder.

And we just had the earliest fall snowfall of
significance in as long as I can remember.

So I guess time will tell. The
sad part missing from the AGW argument is that we should be doing what is right for our planet regardless, across the board. Restoring forests, cleaning water, using clean technology. Then everything else will fall into place. Instead we have a reactionary global society who thinks little for (or of?)itself anymore, and lives on fear.