Here are some of his comments:
Dear Dave,
This is very interesting! I have looked at some specific sites and the
effect of dimming on photosynthesis, but I have not thought about it the way you show it with the keeling curve. Did you try other years as well or did you choose 1960 and 2006 because they are the first and the last?
I am curious and will show it to my colleagues.
Thanks for helping us with our daily science struggle.
Dave,
It becomes more interesting. You may already know that the Keeling data from Hawaii represent Northern Hemisphere biospheric productivity because CO2 is well mixed in the Pacific air mid troposphere. Although major forest fires or extended droughts can affect one year but a general trend is indeed relevant for climate change. Current thinking is that the biological uptake of CO2 in a warming world is reduced which implies a positive feedback (more man-made CO2 produces even more natural CO2). But I have never seen anything with regards to the changes within seasons as you show it. I have to do some more literature search and think about it more carefully.
It is VERY intriging.
-----
As I dug in for more supporting data I found this:
Before 1980 the Month of the Min CO2 levels (trees start to die)
27% in Sept
73% in Oct
Since 1980:
77% in Sept
23% in Oct
Since 1987:
90% in Sept
10% in Oct
There is some possible data that the year after a big Volcano eruption the trees die earlier but I'd need to see daily CO2 values to really show a good chart.
But I did find some data on the New England Foliage season. It is only since 1999 but we have been talking for years that it seems like it comes earlier these days.
When Rachel and I went to Vermont a couple of years ago it was the first weekend of "Foliage Season Rates" at the B&B. But most of the area was at or past its peak.
OK only 7 years but it shows some earlier foliage. At least still interesting.
My next big question is if the leaves change a few weeks earlier than before, how does that impact the amount of CO2 trees could be taking out of the air?
5 comments:
I am so fascinated by this and impressed with the teacher's comments.
If you're ready for that career change...
Keep us posted! I'm intrigued to learn more.
okay, okay, you're a genius. but, i'm still just a little more intelligent. just a smidge.
i think that you shoudl be charging a finding fee for this guy's next publication. :)
Rachel started alot of this, she has been saying for years she thinks all of the seasons are messed up. You tend to think about that when you don't need a jacket to take the dog out in December and most of the snow comes in Feb.
see? this is why we work so well... i'm the idea man, you're the make it happen man.
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