Having seen the website skepticalscience.com recommended by several people as a comprehensive source for all things climate science, I took a look and just for fun did a search for trees - and this is what came up, "Tree-ring proxies and the divergence problem." Probably most people that don't live in a cave have heard about "climategate" and the hacked emails and the "trick" of "hiding the decline" which has supposedly discredited the entire oeuvre of climate science. But linked in the article is a paper from 1998 by Briffa et al, which forthrightly discusses the decline of expected growth in recent decades and speculates...
"Along with climate, relatively large-scale positive growth influences such as hypothesized `fertilization' due to increased levels of atmospheric carbon dioxide or various nitrogenous compounds, or possibly deleterious effects of `acid rain' or increased ultra-violet radiation, might all be expected to exert some influence on recent tree growth rates."
from the discussion:
"K. R. BRIFFA. At this time, we do not know why maximum late-wood density declines in relation to large- scale changes (recent warming) in temperature. Further work needs to be done to investigate the regional and species-specific extent of this phenomenon. However, its widespread and apparently synchronous manifestation, N. America, Europe and Siberia, suggests one or more hemi- spheric-scale factors. Higher UV-B was suggested as an example of one such influence. Some synergistic interaction between different factors is certainly possible, in fact probable.
One could reasonably speculate that CO2 and temperature are implicated, but no more so (given our current knowledge of tree physiology and what experimental work has been done) than, say, higher nitrate levels or perhaps tropospheric ozone. It is salient to note that relative tree-ring width, and basal area increment, also show a relative decline and divergence from the temperature curve(s), arguing against the decline in density being a compensation reaction to increasing ring growth (as is seen in forestry soil fertilizing experiments).
I would imagine that higher temperatures, and possibly some increasing sensitivity to lower summer soil moisture are involved, but some additional growth-limiting factor must also be implicated. Higher CO2 would be expected to increase basal area growth, so I consider it unlikely that this is the factor."
Hmmm...acid rain...higher nitrate levels...tropospheric ozone...UV radiation...
All this from 1998! There is much more, but I'm so disgusted that nobody is paying attention to the catastrophic implications of "widespread and synchronous manifestations" of tree decline that I feel like screaming. Every day we do nothing and let the anti-science cretins dominate the conversation is compounding the misery we will leave for future generations, of which at the current rate of transition to clean energy, there will not be very many!
Arctic Sea Ice Belching Tons of Methane couldn't be much nastier news. Here's the graph:
Methane is actually escaping from the permafrost and dissolving in the water, working it's way to the surface. File this under the mushrooming category: "Faster and Worse than Predicted."
Gail, you might look into the writings of John Ott. He did the earliest research on the effects of different light spectrums on growing plants. He did the earliest Walt Disney time-lapse movies of plants growing and flowers opening. (You probably saw them as a child.) He discovered that the frequency spectrum of the light that he used made all the difference in how his plant subjects grew. I read his interesting books 30 years ago. At that time no one in industry or science was interested in his discoveries.
ReplyDeletehttp://en.wikipedia.org/wiki/John_Ott
You know me as slanted tom and catman306 at Climate Progress.
Thank you catman306/slantedtom, I will check into that!
ReplyDeleteAre you saying you think it is a difference in the light? Briffa alluded to extra UV radiation coming in thanks to less ozone in the stratosphere. I wonder about that too especially this winter seeing the top layer of evergreens has such different pigment than lower layers that don't get direct sunlight.
On the other hand, there's all that radiation from cell phone towers...to many effects all at once!
Well, I have no way of measuring the relative energy levels across the visible spectrum (and a little on each side). I think John Ott measured sunlight across the spectrum in the 1950s. Surely someone has done so today. I think that Ott found that fluorescent and mercury vapor lamps have an unusual spike of energy related to elemental mercury and that those types of artificial lamps are harmful to some plants. That why they make 'grow' lights which have no energy spike.
ReplyDeletePurely speculating, I wonder if mercury air pollution is somehow being excited on an atomic level and adding that mercury spike to normal daylight.
When I wonder if our light energy spectrum for daylight at the ground has changed in anyway, I realize, of course it has, because we have different pollution now then before the industrial revolution. And different pollution now than when John Ott took his measurements.
Chances are that plants have noticed the difference too.
Yes! Mercury + cell phones!
ReplyDeleteThe main problem here is that to figure this out requires collaboration from several disciplines of science that rarely intersect.